EMDEC troubleshooting tool

8/10/2019 EMDEC troubleshooting tool

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Electro-MotiveDiesel Engine

EMDECOperating &

Troubleshooting

Guide


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Acknowledgments

The EMDEC Operating & Troubleshooting Guide has been preparedfor use by qualified personnel engaged in the maintenance and repair ofelectronic fuel injection systems on Electro-Motive diesel engines.

Always refer to the correct electrical schematic for the specific application.

NOTE:

To ensure compliance with emission standards and warranty

conditions, use only by O.E.M. certified replacement pads. Consult

the appropriate Service Parts Catalogue for the application.


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Table of Contents

Introduction and System Development

1.1 INTRODUCTION .......................................11.2 REASONS FOR DEVELOPMENT

OF EMDEC ...............................................11.3 EMDEC COMPONENTS ...........................21.3.1 Engine Control Modules (ECMs) ..........2

1.3.2 Electronic Fuel Injectors (Two-stroke).... 31.3.3 Electronic Fuel Pumps & Injectors

(Four-stroke)............................................41.3.4 Sensors ....................................................51.3.5 Power Supply & Interface Module .........51.3.6 CONCLUSION ..........................................5

1.3.7 EMDEC GLOSSARY OF TERMS.................6

EUI Fuel Delivery System

2.1 INTRODUCTION .......................................92.2 THE 710 TYPE FUEL SUPPLY SYSTEM .........92.2.1 Suction Strainer ................................... 112.2.2 Fuel Pump ............................................ 112 2 3 Fuel Preheater & Primary Fuel Filters 12

Chapter 1

Chapter 2


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Electronic Injection Equipment -Fuel Components

3.1 INTRODUCTION .................................... 233.2 710 SERIES ELECTRONIC

UNIT INJECTOR ..................................... 233.2.1 Control Portion (Solenoid) .................. 253.2.2 Armature .............................................. 253.2.3 Hollow Poppet Valve ........................... 253.2.4

High Pressure Pump Portion ................ 263.2.5 Injector Portion .................................... 263.2.6 Fuel Flow Through The EUI ................... 263.2.7 Operation Of The EUI ........................... 283.2.7.1 Start Of Injection.................................. 293.2.7.2 Piston Rises In Cylinder ........................ 30

3.2.7.3 Fueling Decisions................................. 303.2.7.4 Injection ............................................... 303.2.7.5 Bleeder Passages ................................ 323.2.7.6 End Of Injection ................................... 323.2.7.7 Injector Feedback To

The EMC (Response Time) .................. 33

3.2.7.8 Injector Response Time ....................... 343.3 H SERIES ELECTRONIC

INJECTION EQUIPMENT ........................ 343.3.1 Pump Operation.................................. 353 3 1 1 Start Of Injection Sequence 35

Chapter 3


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EMDEC Electronic Components & Operation

4.1 INTRODUCTION.................................... 394.2 ENGINE CONTROL

MODULES (ECMS) .............................. 414.2.1 Arrangement ...................................... 424.3 POWER SUPPLY .................................... 444.4 INTERFACE MODULE ............................ 464.5 SPEED CONTROL ................................. 474.5.1 Speed Control - One-Way Serial

Link (Locomotive Application) .......... 474.5.2 Speed Control - Two-Way Serial

Link (Locomotive Application) .......... 484.5.3 Speed Control (Marine

Application) ........................................ 484.5.4

Speed Control (PowerGeneration) ........................................ 484.6 SENSORS .............................................. 514.6.1 System Sensors ................................... 524.6.1.1 System Sensor Mounting

Arrangements - Early 710 Series ........ 53

4.6.1.2 Setting SRS & TRS Sensors ................... 544.6.1.3 System Sensor Mounting

Arrangements - H Series ..................... 544.6.1.4 Synchronous Reference Sensor ......... 554 6 1 5 Timing Reference Sensor 55

Chapter 4


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Load Control

5.1 INTRODUCTION.................................... 735.2 FUEL MAP ............................................. 755.3 CONTROLLING ENGINE SPEED ............ 765.4 % ALLOWABLE TORQUE SIGNAL .......... 78

Diagnostic Tools

6.1 INTRODUCTION.................................... 816.2 WINEMMON & PC READER

(DIAGNOSTICS WITH A LAPTOP PC) ... 826.2.1 Using The WinEMMON

Or The PC Reader Kit .......................... 836.2.2

Loading WinEMMON Software OnTo A Laptop Computer ......................... 846.2.3 Loading The PC Reader

On To A Laptop Computer ................ 866.2.3.1 To Edit The EMMON Command File .. 876.2.3.2 Connecting the WinEMMON

And The PC Reader to EMDEC .......... 876.2.3.3 Access Ports ........................................ 886.2.4 Utilizing WinEMMON & The PC

Reader Program ................................... 906 2 5 WinEMMON Main Screen 92

Chapter 5

Chapter 6


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6.2.8.1 Injector Rise Time .............................. 1136.2.8.2 Injector Calibration .......................... 1136.2.8.3 Calibration Process ............................. 1146.2.8.4 Injector Cut Out ................................ 115

6.2.8.5 Pulse Width ........................................ 1166.2.9 Bus Monitor......................................... 1176.2.10 Miscellaneous Screen ...................... 1216.2.11 Help ................................................... 1256.2.11.1 Help Topics ........................................ 1276.2.11.2 Faults ...................................................1326.3.1 PC Reader Main Screen ......................1386.3.1.1 ECM Data Boxes ............................... 1386.3.1.2 Engine Parameter Data Box ............ 1396.3.1.3 Editing The Main Screen .................. 1426.3.1.4 Injector Response Time ....................... 1446.3.1.5

Using The Injector Screen ................ 1446.3.1.6 Fault Data ......................................... 1456.3.2 Using The Diagnostics Screen.......... 1466.3.2.1 To View The Faults............................... 1476.3.2.2 To Save Archived Faults To A

File (EMDEC Fault Download) .......... 147

6.3.3 Using The Download Function ............ 1486.3.4 Using The Sensor A/D

Value Screen .................................... 1576.3.5 Using The Digital I/O Pins ................. 1586 3 6 Other PC Reader Functions 159

Chapter 6cont.


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Chapter 6cont.

6.4.1.4 Low Water Pressure Light ......................1656.4.1.5 Crankcase Pressure Light .....................1666.4.1.6 System Reset........................................1666.4.1.7 Engine Diagnostic Lights ......................1676.4.1.8 Stop Engine Light (SEL) ........................1676.4.1.9 Check Engine Light (CEL) .................... 1686.4.1.10 Fuel Injection Switch ............................ 1686.4.1.11 System Ready Light ..............................1696.4.1.12 Code/Test Switch ................................1706.4.2 Reading Diagnostic Codes

- Flash Method..................................... 1706.4.3 EMDEC Diagnostic Codes ...................172

Maintenance Procedures

7.1 EMDEC Injector Change-Out And

Setting Procedures.............................. 1797.1.1 Change-out And Setting

Procedures For 710 Series Electronic

Unit Injectors (Including Timing

Procedures) ...................................... 1797.1.1.1 Removing Existing Injectors

From Engine ...................................... 1797.1.1.2 Installing New Injectors In Engine .... 1807 1 1 3 Timing The Electronic Unit Injectors 183

Chapter 7


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7.4 70/80/90 MAC PLATFORM STYLE FUELSYSTEM CHECK VALVE REMOVALINSTRUCTIONS ................................... 202

7.4.1 Instructions For Engines With

Filters Mounted On Right FrontCorner Of Engine - 40 PSIValve ................................................. 202

7.4.2 Instructions For Engines WithFilters Mounted On Right FrontCorner Of Engine - 120 PSI Check

Valve ................................................. 2037.4.3 Instructions For Engines WithCenter Mounted Filters -120 PSI or 40 PSI Check Valve .......... 206

7.5 REPLACING EMDEC TERMINALS ........ 2087.5.1 Airbox Pressure (MAP) Sensor .......... 2087.5.2

Engine Protector ............................... 2097.5.3 Remaining Sensors And AllConnectors Into The ECM ................ 210

7.5.4 Power And Sensor Harness

Connectors - 12 Cylinder Engines ... 2117.5.5 Sensor Harness Connector - 16

Cylinder Engines ............................... 2127.5.6 Power Harness Connector - 16

Cylinder Engines ............................... 2137.5.7 Pig-Tail Temperature Sensor Plug .... 2137.5.8 AMP Plugs At Power Supply

Chapter 7cont.


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Chapter 8cont.

8.2.1.4 Check Fuel Pump Operation ........... 2198.2.1.5 Check Magnetic Pickups (TRS/SRS).... 2198.2.1.6 Check For Active Communication

Failures ............................................... 220

8.2.1.7 Check Plug Connections ................. 2208.2.1.8 Check For Injector/Sensor

Harness Grounds .............................. 2218.2.1.9 Check Turbocharger ........................ 2218.2.1.10 Replace ECM Module ...................... 2218.2.2 Unit Not making Horsepower ........... 2228.2.2.1 Check For EngineR Value ................ 2228.2.2.2 Check The Individual Injector

Response Time.................................. 2228.2.2.3 Check The Inlet Fuel Pressure .......... 2238.2.2.4 Check Plug Connections ................. 2248.2.2.5

Check The Airbox Sensor(MAP Sensor) .................................... 2248.2.2.6 Check The Injectors.......................... 2258.2.3 Unit Loading At 90%.......................... 2258.2.3.1 Check For EMDEC

Communication Faults..................... 225

8.2.4 Throttle Request Problems................ 2278.2.4.1 Check The EM2000 ........................... 2278.2.4.2 Check The Connections At The

Interface Board................................. 2278 2 5 Protective Engine Shutdown 229


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Chapter 8cont.

8.3.1 No Lights On 24V Power Supply....... 2378.3.2 Red Light Glows On 24V

Power Supply .................................... 2378.4 EMDEC WIRING VISUAL INSPECTION 2398.4.1 Open Circuit ..................................... 2398.4.2 Short Circuit ...................................... 2398.5 TROUBLESHOOTING TRS & SRS .......... 2408.5.1 Troubleshooting The TRS/SRS

Sensor Circuit .................................... 2408.6

TROUBLESHOOTING SENSORCIRCUITS ............................................ 2428.6.1 General Information ......................... 2428.6.2 Troubleshooting The Crankcase

Pressure Detector Circuit

Switch Output ................................... 243

8.6.3 Troubleshooting The AnalogCrankcase Pressure Sensor

Circuit (Analog Output) ................... 2468.6.4 Troubleshooting The Coolant

Pressure Circuit ................................. 2508.6.5 Troubleshooting The Coolant

Pressure Circuit ................................. 2538.6.6 Troubleshooting The Oil Pressure

Circuit ................................................ 2568.6.7 Troubleshooting The Oil

Pressure Circuit 259


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Chapter 8cont.

8.10 TROUBLESHOOTING FLOWCHARTS ... 2708.10.1 Fault Code 994 ................................. 2708.10.2 Fault Code 996 ................................. 2738.10.3 Fault Code 997 ................................. 2768.10.4 Fault Code 998 ................................. 2798.10.5 Fault Code Generic.......................... 2828.10.6 710 Engine Starting Problems .......... 2908.11 EMDEC TROUBLESHOOTING

QUICK REFERENCE GUIDE ................. 301

System References ComponentLocator Charts

A.1 EMDEC QUICK LOCATOR CHART ..... 307

EM2000 EMDEC Signal Acronyms

B.1 EM2000 EMDEC SIGNAL

ACRONYMS ....................................... 315

B.2 EMDEC ACRONYMS .......................... 320

System References

Appendix A

Appendix B

Appendix C


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1

Introduction &System Overview

INTRODUCTION

1.1 This manual has been prepared for personnel involvedin the maintenance and repair of the General Motors

EMDEC (Electro-Motive Diesel Engine Control)fuel injection system. This electronically-controlledfuel delivery system is currently available for the 710series, and 265H series diesel engines, and as a retrofitto appropriate older engines. EMDEC is applicable torail, power, marine, and industrial applications.

This text is intended to provide a solid workableknowledge of the basic EMDEC system, itscomponents, operation, and troubleshooting.

Due to the significant variations between equipmentapplications, the system used in this presentationreflects a basic configuration. Always refer to thecorrect Engine Maintenance Manual (EMM), andwiring schematic for specific service data.

EMDEC system diagnostics may be performed usinga laptop computer with a diagnostic program calledWIN-EMMON, and in some locomotiveapplications, by using the EM2000 control computer.This text will illustrate diagnostic techniques for both


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ECMs

INJECTORS

SENSORS

An additional benefit is the ease with which the systemcan be modified. By altering the programming withinthe control modules, the same physical componentscan be used on different engines, or for different

performance ratings.

The EMDEC system consists of several maincomponents that are common between most engineapplications. These components will be examined indetail later in the text. A brief description follows.

EMDECCOMPONENTS

1.3

1 1 C


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1

EMDEC equipped two-stroke EMD engines useelectronically-controlled unit injectors. The injectorsare fitted to the cylinder heads in a similar manner tothe mechanical style. However, instead of a mechanical

linkage, a wiring harness connects each injector to itscontrolling ECM.

Electronic UnitInjectors(Two-Stroke)

1.3.2


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Unlike the unitized injector on the 710 series ofengines, the 16V265H engines are currently equippedwith separate fuel pump and injector (nozzle)assemblies for each cylinder. Although separate

components, they function in a manner identical to theunitized assembly. Bosch manufactures the four-strokeinjection equipment to EMD specifications. Like otherEMDEC applications, all fuel pumps are connected tothe controlling ECM by an electrical harness.

Electronic FuelPumps &Injectors(Four-Stroke)

1.3.3


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1

Sensors

1.3.4 EMDEC uses various sensors to determine crankshaftspeed and position, system pressures, and temperatures.The sensors are connected to the ECMs by means ofexternal wiring harnesses .

The 24 volt power supply and interface moduleconverts control system voltage into a stable 24volts, as required by the EMDEC components.

In addition, the interface module allows forcommunication between the injection system and thecontrol system. Speed inputs for example, are convertedfrom the solenoid commands found on a Woodwardgovernor, into RPM requests that are understood by theEMDEC system.

EMDEC is by no means afinished system. Assystem and performance requirements change, thecomponents and programming are being refined

to better meet the needs of our customers. Olderapplications are upgraded to reflect the changesand maintain commonality of components.

Power Supply& Interface

Module

1.3.5

Conclusion

1.3.6


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ECM Engine Control Module.

EM2000 Locomotive control computer.

EMDEC Electro-Motive Diesel EngineControl.

Engine Ratio Expression of amount of fuel beingconsumed as a percentage of totalavailable fuel at a given engine

speed.

Engine_R Engine ratio as seen on the EM2000computer.

EUI Electronic Unit Injector

MUI Mechanical Unit Injector

Pulse Width Duration of an injection sequence,measured in degrees of crankshaft

rotation.

SRS Synchronous Reference Sensor, usedfor timing and speed signal.

EMDECGlossary OfTerms

1.3.7


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1

Notes:


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Notes:


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2

EUI Fuel SupplySystem

NOTE:

INTRODUCTION

In operation, the basic fuel supply systems used withEMDEC-equipped engines function similar to MUI

equipped systems. Major differences include filtration,fuel pressures, and fuel volume. This section of the textwill trace the fuel flow through two typical systems,those applied to typical 710 applications, and as appliedto the 6000 HP 265H application. Due to thedifferences between equipment, always refer to thespecific service publications for your applications.

The function of the fuel supply system is to provide theinjectors with a supply of filtered fuel in quantity, and

at pressures adequate to ensure proper performance.Figure 2.1 on the following page shows the basic systemas configured for a typical 710 engine locomotiveapplication.

2.1

THE 710 TYPEFUEL SUPPLYSYSTEM

2.2

Before performing maintenance or diagnostics on the

fuel system, ensure that the proper system schematic is

available for reference.


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reliefvalve120psi.

(tak

esplaceofbypasssigh

tglass)

vent

suctionstrainer

600

electrically

driven

pump

thermostatic

modulating

valve

fuel

preheater

enginejacket

water

primary

fuel

filter13

bypass

valve30psi.

platform

/core

elements

nitinjectors

fuel

pressure

sensor

fuel

temperature

sensor

secondaryfu

el

filters5

(spin-on)

cold

plate

electronic

control

modules

fuelout

fuelin

-

-


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2

As in the MUI system, fuel is pulled from the fuel tankthrough a suctionstrainer by thefuel pump. This

strainer, mountedon the equipmentrack (figure 2.2)protects the fuelpump from anylarge debris

contained in thetank.

The fuel pump (figure 2.3) is typically mounted onthe equipment rack. The pump has been increased incapacity over MUI systems, with output between 5.5and 8 GPM depending on the application. While stillsupplied with 74 VDC from the control system, themotor carries its own inverter pack, and operates on

AC to eliminate brush and commutator maintenance.

Suction Strainer

2.2.1

Figure 2.2 Suction Strainer.

Fuel Pump

2.2.2


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Most EUI systems are equipped with a fuel preheaterand thermostatic modulating or AMOT valve (figure2.4). Inlet fuel temperature is monitored by this valve,which has a setting of 75 F(96 F on previous

locomotive models). Should fuel temperature dropbelow the nominal setting, fuel will be directedthrough the fuel preheater where it is warmed byengine cooling water.

Fuel next flows to the 13 micron primary fuel filters

(figure 2.4).These filters are equipped with a bypassvalve that will allow fuel to flow around the filters tothe engine, if the filters plug. Should the filters beginto plug, the pressure will increase in the line betweenthe primary filters and the fuel pump.

Fuel Preheater& Primary FuelFilters

2.2.3

PRIMARY

FUEL FILTERS

FUEL

PREHEATER


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2

The bypass begins to open (crack) at 25 psi, and is fullyopen at 30 psi. Any impurities in the fuel will be trappedby the secondary filters which will quickly plug.

On certain EUI applications, pressure transducers havebeen added to the filter inlet and outlet lines, connectedto the control system. Should the pressure differentialacross the primary filters exceed 25 psi, the controlsystem will indicate a plugged filter condition.

On later models without spin-on secondary fuel filters,primary filters are 5 microns and the bypass valve islocated between the fuel pump and the thermostaticvalve to direct fuel to the tank in the event of pluggedfilters.

From the primary filters, fuel now travels to a fuel blockat the bottom right front of the engine from which 3steel tubes (or flexible hoses on some applications) runvertically up to the Secondary Spinon Fuel FilterManifold. This fuel block feeds fuel to the Spin-on Fuel

Filter Manifold and receives return fuel from theengine. The 3 fuel lines coming from the block are:

Fuel Block

2.2.4


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In early models the fuel enters the Spin-on SecondaryFuel Filter Manifold. Depending on the application,this manifold may be:

mounted on the right front corner of the engine (figure 2.5a),

mounted on the front center of the engine (figure 2.5b),

SecondaryFuel FilterManifolds

2.2.5


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2

Figure 2.5b Front Mounted Filters.

NOTE:

Due to the increased fuel pressure and risk of fuel

leaks at this location, the sight glasses have been

eliminated on later EMDEC applications.


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NOTE:

Regardless of the mounting application, internalporting within the manifold allows the fuel to flow tothe cracking side of the high pressure filter bypassvalve, and both spin on secondary filters. Bypass valve

is located internally in the housings without sightglasses. On EUI applications, these filters have a 5micron rating. The element size has been increasedfrom previous systems to allow a greater fuel flow rate.Fuel pressure is monitored by EMDEC at this point,by means of a pressure transducer located in the upper

left-hand portion of the manifold, when facing thefront of the engine.

In previous models, if the primary fuel filters are

bypassing, the Secondary Spin-ons will quickly plug up.

Back pressure between the secondary filters and the fuel

pump will rise, causing the high pressure bypass valve to

open. Fuel will flow through the high pressure bypass

valve and from there back to the fuel tank. Unlike the

primary bypass, when the secondary filters plug, the

engine will starve for fuel causing major performance

problems. Changing of both primary and secondary fuel

filters is mandatory on all EMD engines.


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2

For applications with the filter mount on the frontright corner of the engine, fuel leaves the manifoldand enters a ported fuel distribution block mountedon the front center of the engine. From this fuel block,

supply lines connect to the right and left bank fuelmanifolds to supply the fuel injectors. On engineswith the filter manifold mounted in the center of theengine, fuel is routed directly to the fuel manifolds inthe top decks of the engine.

Fuel travels down the upper line of the manifold,down each bank of the engine, terminating at the lastcylinder on each side. Note that the fuel manifoldshave been increased in size to 7/8" diameter.

Each injector is supplied with fuel through fueljumpers as on MUI systems. The jumpers however,are now a flexible line with a larger diameter (figure2.6). The fuel enters the fuel injectors through a smallin-line filter element, then circulates through theinjectors internal passages. A portion of the fuel is

used for injection, the remainder is returned to thefuel tank. Note that lubrication and cooling of thefuel injector is done with this excess fuel flow as inprevious systems. For a more detailed operation of

Fuel Injectors

2.2.6


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Fuel now leaves the injector through the jumper lineto the lower line of the fuel manifold. In previousmodels, the return fuel flow from the manifolds isrouted through cold plates (if applied) attached to the

front face of the ECMs. The cold plates consist of ablock with milled fuel passages covered with a thinplate. As return fuel temperature is nominally 120 -140 F and does not change quickly, this fuel is used tostabilize the temperature of the ECMs.

From the cold plates, the return fuel is directed to thereturn fuel check valve.

On previous systems equipped with sight glasses, thisvalve is located under the return fuel sight glass (closestglass to the engine). On most EMDEC systems, thevalve is mounted inside the filter manifold block. Thecheck valve ensures that the system maintains back

Return Flow

2.2.7

Check Valve

2.2.8

NOTE:

This check valve may have a rating between 30 and 60psi, depending on application. Ensure that you consult the

Engine Maintenance Manual for the correct check valve

application.


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2

While the basic fuel supply system applied to Hengines performs the function as the 710 typesystems, there have been several major changes tothe operation.

The fuel supply system (figure 2.7) begins with the fueltank (a).

The tank is equipped with drains for the fuel side and

the retention tank portion.

Fuel is drawn up to the engine through the suctionstrainer (b) that serves to protect the fuel pumps.Certain 265H engine applications are equipped with

two fuel pumps, one electrically-driven (c), and onemechanically-driven (d).

The electric fuel pump is used for priming the engineprior to startup; normal engine operation is with themechanical pump only.

The electric fuel pump is a diaphragm-type pumpcontrolled by the EM2000 and is mounted below the

265H TYPEFUEL SUPPLYSYSTEM

2.3

Fuel Tank

2.3.1

SuctionStrainer

2.3.2

Fuel Pump

2.3.3


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TO

TANK

FUEL

TANK

D.MECHANICAL

FUELPUMP

EMDEC

FUELPRESSURE

SENSOR

FROM

PUMP

LBS

RBS

LBR

RBR

B.SUCTIO

N

STRAIN

ER

FUEL

TEMPERATURE

L URE

E.FUELFILTER

PRE

HEATER

DISTRIBUT

ION

BLOCK

C.ELECTRIC

LIFTPUMP

F.FUEL

DIST

BLOC

K


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2

The fuel filter (e) is a paper element type rated at 13microns and is equipped with a 25 psi bypass valve.Note the increased size of the filter to handle thegreater flow rate of the new system.

From the filter, fuel is transferred to the fueldistribution block (f) mounted on the front of theengine. Flow is divided at this point and directed to thesupply rails (g) running down each bank of the engine.

At each cylinder location, flexible jumpers carry asupply of fuel to the rocker box housing, then withinternal jumpers, across to the pump body.

The injection pumps use a portion of the fuel supplyfor engine operation, the remainder carries excess heatfrom the pumps back to the return side of the system.Through another set of flexible jumpers, return fuel isrouted into left and right bank return fuel rails (h). Atthe front of the engine, fuel is directed from eachreturn rail to a cold plate mounted to that banks ECMto stabilize temperatures within the unit. From thecold plates, fuel then travels to the fuel distributionblock where a return check valve ensures proper

Fuel Filter

2.3.4

FuelDistributionBlock

2.3.5

InjectionPumps

2.3.6


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Notes:


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Figure 3.1 Electronic (EUI) and Mechanical (MUI) Injectors.

The EUI may be broken down into three basicsections - control, high pressure pump, and injector(figure 3.2).

CONTROL

PORTION

HIGH

PRESSUREPUMP

E Coil

Stator

Armature


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The high pressure pump portion is made up of theplunger assembly and the injector body portion. Theplunger is operated by the camshaft through theinjector rocker mechanism, similar to a mechanical

injector. Downwards motion of the plunger is used togenerate the high pressures required for injection.Note that the diameter of the plunger is slightlysmaller than the diameter of the cylinder. The fillpassage for the pump chamber is located at the upperleft corner in the illustration. At no time is this passage

blocked by the plunger, which simply acts to displacea volume of fuel in the chamber.

The actual injector forms the lower portion of theassembly, and protrudes into the combustion

chamber. The injector is comprised of a check valve,needle valve, needle valve spring, and spray tip. Thespray tip has orifices that atomize the fuel as it isforced through the tip into the combustion chamber.

Fuel flows from the flexible jumper line to the EUI,entering through its inlet filter located in the body ofthe injector. Refer to figure 3.3 which shows the fuelflow in the EUI in the de-energized state (no

High PressurePump Portion

3.2.4

Injector Portion

3.2.5

Fuel Flow ThroughThe EUI

3.2.6


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3

Figure 3.3 Flow of Fuel Through EUI (no injection).

An internal passage directs fuel to the control portionof the injector, filling the armature chamber below theE coil stator. The flow of fuel through the armatureh b l h d l idi


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If the injector is de-energized, the poppet valve is openallowing fuel to flow upwards around it. This fueltravels into a drilled passageway to fill the highpressure pump chamber below the plunger. As in the

previous systems, it is important to note that most ofthe fuel sent through the injector is used for coolingand lubrication; only a small amount is actually usedfor injection.

The EMDEC electronic unit injector is bothelectrical and mechanical in operation. It performs thefunctions of metering and timing electronically, whilethe functions of pressurizing and atomizing are stilldone mechanically.

The metering and timing functions are controlled bythe ECMs, which fire each individual EUI at aprecise point in time for a specific duration.

This action is based on the software programcontained in the ECMs and inputs into the ECMssuch as:

speed requests from the control system via the interface module,

Operation OfThe EUI

3.2.7


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3

Top View of Injector

Poppet Valve Closed

Injection Cycle

Fuel Lubricating

and Cooling

Injector Plunger

High Pressure Bleed

Pass Return

Fuel Supply Flow

Fuel Return Flow

Trapped Fuel for Injection

Bleed Return Fuel

710 Cylinder Head

Adapter Collar

The easiest way to understand the operation of theEUI is to follow it through a typical injectionsequence. Refer to figure 3.4 for the flow of fuelthrough the injector during an injection sequence.

Start Of Injection

3.2.7.1


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The high pressure generated in the pump chamber isalso transmitted downwards to the spray tip throughthe column of fuel and the check valve. As thepressure increases, it pushes outwards in all directions

in the tip area, including backwards against thetapered surface of the needle valve. When the pressurein the tip area has reached between 2000 psi and 2400psi, the needle valve will be lifted off its seat againstthe needle valve spring. This allows fuel to flowthrough the needle valve and the orifice holes in the

spray tip, into the cylinder.

The continued downwards motion of the plungercauses the pressure in the injector to rise to the finalworking pressure of between 16,000 psi and 18,000psi. Note that once injection has begun and the

injector has reached the final working pressure, theflow rate of the tip cannot be changed. For a givenperiod of time, the injector will deliver a measuredquantity of fuel. As with any injection system, what hasto be varied is timing (start of injection) and duration(pulse width). The injector will continue to inject fuelinto the cylinder as long as: a) the solenoid isenergized, and b) the injector plunger is movingdownwards.


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Top View of Injector

There are two additional passages shown in theillustration. These bleed passagesprevent the escapeof high pressure fuel to the outside of the injector.

During the high pressure process, fuel bleeds upwardsaround the EUIs plunger for lubrication. This fuel iscollected in the bleed passage and fed into the EUIsfuel return system to prevent further migration upwards.Due to the extremely high pressures involved, someleakage will take place between the components above

the injector tip. A second bleed passage gathers fuel inthis area to prevent leakage between the body portionand the lower housing. Again, this fuel is fed back to thelow pressure return system of the EUIs.

When the ECM has determined that injectionshould cease, it simply turns offthe injector byde-energizing the solenoid. This allows the armaturereturn spring to drop the armature and poppet valveagainst the bench in the lower fuel chamber.

BleederPassages

3.2.7.5

End Of Injection

3.2.7.6


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3

As the poppet valve opens, the high pressure fuel in thepump chamber is allowed to escape back through thevalve to the return fuel system. The pressure in thechamber drops instantly to end injection. When the

pressure coming from the pump chamber to the injectortip drops below 2000 psi, the needle valve return springpushes the needle valve back against its seat to close thepassage through the tip to the spray orifices.

Note that the check valve in the injector will not allow

the flow of fuel pressure back into the pump chamberfrom the tip. This serves several purposes. First, byretaining a certain amount of pressure in the tip (slightlybelow the injectors cracking pressure), the response timeof the injector for the next sequence is improved.Second, in the event of a leakage in the needle valve,

combustion gases will not be allowed to work their waythrough the injector into the fuel system.

The final action in the injector is the return of theplunger to its initial position. As the camshaftmechanism rotates further, the plunger return springmoves the plunger upwards to the top position. Thisupwards movement draws fuel back into the chamberfrom the poppet valve, refilling the chamber for the nextinjection sequence


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This feedback is called injector response time. Typicalresponse times will be in the range of 1.30 to 1.50milliseconds. Each injector will vary slightly, but allshould have approximately similar times. When

checking injector response times using a laptopcomputer, any injector with a response timesignificantly different from the rest may indicate afaulty injector or defect in the wiring harness. Theproblem must be diagnosed, and corrected before theengine is returned to service.

Although the ECMs can monitor the injectorselectronic performance, the mechanical portions arestill subject to failure requiring more in depthdiagnosis. These procedures will be covered in thesection on Troubleshooting settings and adjustments

are covered in a separate section.

The injection pump and nozzle (figure 3.6) functionin an identical manner to the electronic unit injectorfound on the 710 series of engine, however they have

now been divided into two separate, largercomponents. Theinjection pump islocated on the upper

InjectorResponse Time

3.2.7.8

H SERIESELECTRONICINJECTIONEQUIPMENT

3.3


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3

Pump Operation

3.3.1 Internally, the pump (figure 3.7)is similar to the pumpportion of the 710 electronic injector. The plungertravels in a chamber that is connected to the fuel supplysystem by a fill passage. Operation of the fill passage iscontrolled by the Engine Control Module, using apoppet valve mechanism with a 24 volt coil. In thede-energized state, upwards movement of the plungerdisplaces fuel from the pump chamber, back throughthe poppet valve to the supply system.

When the ECM determines that injection shouldbegin, the coil is energized to close the valve. Furtherupward movement of the plunger results inpressurization of the fuel in the chamber, which isdelivered to the nozzle through the delivery passageand check valve.

On completion ofinjection, thepoppet is de-energized torelease the fuelpressure back tothe supply system.The downward

To InjectorFuel Inlet

Start Of InjectionSequence

3.3.1.1

End Of InjectionSequence

3.3.1.2

Poppet

Valve


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The injector (figure 3.8)is mounted on the top of thecylinder head on the vertical centerline of the cylinder.The injector receives a supply of high pressure fuelfrom the pump through the high pressure jumper line

during the injection cycle. As the fuel pressure risesdue to the closing of the poppet valve, the pressurebuilds internally in the nozzle. When the pressure issufficient to lift the needle valve off its seat against thespring, fuel is allowed to flow into the engine cylinderthrough the spray tip. The fuel is atomized and mixes

with the air in the cylinder for combustion. At the endof the injection phase as fuel pressure drops, theneedle reseats to block the flow of fuel into thecylinder.

The bleed off (or leak off)line serves the samefunction as the internalbleed passages in the olderstyle unit injectors. Internalhigh pressure leakage

between components in thenozzle assembly is collectedand routed back to thereturn fuel system before it

Bleedoff

Highpressure

from

pump

INJECTOROPERATION

3.4

BLEED OR LEAKOFF LINE

3.5


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3

Notes:


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Notes:


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4

EMDEC ElectronicComponents &Operation

This section of the text will concentrate on theelectronic components that make up EMDEC, andhow the systems function to control injection. For thepurpose of instruction, a typical 16-cylinder 710engine application is used. 265H engine applicationsuse a similar control method.

The text will use a building block approach, discussingeach component in detail as it pertains to operation.The main electrical and electronic components of theEMDEC system are:

1. ECMs (Engine Control Modules): The actualinjection control computers.

2. Power Supply: 74 VDC to 24 VDC EMDECpower source.

3. Interface Module: Communication interfacebetween EMDEC and the main controlsystem.

4 S E i f

INTRODUCTION4.1


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4

As stated before, the main components of the systemare the engine mounted ECM's. These units are self-contained microprocessors that operate on 24 VDC.Each ECM has the ability to control up to 8 injectors.

Therefore, the number of ECM's applied depends onthe engine configuration for example:

8-cylinder engine has one ECM.

12-cylinder engine has 2 ECM's (right bank 1

thru 6, left bank 7 thru 12).

16-cylinder engine has 2 ECM's (right bank 1thru 8, left bank 9 thru 16).

20-cylinder engine has 3 ECM's (right bank 3thru 10, left bank 13 thru 20, center (1,2,11,and 12).

ENGINE CONTROLMODULES (ECMS)

EM200074 VDC

ABCD

74 VDC

ABCD

FAULT DATA

TIMING & SPEED INFOSRS

TRS

RPM

24 VDC

Request24 VDC

POWER

SUPPLY

LOCO

INTERFACE

4.2


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Physically all ECMs are identical, but the software isdifferent for each unit. Every application has oneECM designated as a sender (or controlling) ECM.The software provides the units identity as well as the

application specific operating parameters (speedschedules for example). The sender is responsible forprimary data processing, and overall control of enginefunctions. The remaining ECMs carry the designationof receiver(s).

Receiver ECMs are controlled by the sender ECM,which provides basic information such as injectionpulse width (fuel amount), and base injection timing.Remember, the number of receiver ECMs dependson the number of engine cylinders. The softwareallows for some independent operation of the unit, and

engine RPM requests and basic timing feedbacks arefed to the receiver(s), independent of the sender. Thiswill allow the system to overcome intermittentcommunication problems between the sender andreceiver(s).

The location of the ECMs on the engine will varydepending on application.

Early 16-cylinder 710 models have the ECMs

Arrangement4.2.1


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In previous models, the Power Supply (figure 4.3)onthe following page is located in the AC Cabinettowards the rear of the locomotive. Later models havethe power supply located in the electrical locker nearthe door.The function of the power supply is to stepdown and filter the 74 VDC control system voltage to24 VDC. EMDEC was originally designed for heavytruck type applications, therefore operates on a systemvoltage of 24 VDC. The output of the power supply isfed directly to the interface module, and through a

power harness, to the engine mounted ECMs.

In applications other than locomotive, control systemvoltage will be filtered and regulated to provide astable 24 VDC supply. While the appearance of thepower supply will be different, the function remains

the same.

The Power supply is fed through the engine controlcircuit breaker located on the fuse and circuit breakerpanel. Note that both the positive and negative sides ofthe circuit are protected. The power supply is

equipped with two LEDs (light emitting diodes) on itsface to indicate status.

The green LED (normally on) indicates that the

POWER SUPPLY

4.3


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4

EM200074 VDC

ABCD

74 VDC

ABCD

FAULT DATA

TIMING & SPEED INFO

FEEDBACKS

INJECTORS

9-16

INJECTORS

ECM

RECEIVER

ECM

SENDER

F P

F T

SRS

TRS

RPM

24 VDC

Request

AP

O P

O T

24 VDC

POWERSUPPLY

LOCOINTERFACE


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INTERFACEMODULE

In previous models, the Interface Module is located inthe AC cabinet of the locomotive, and is typicallymounted on the side of the power supply. Latermodels have the interface module located in theelectrical locker. The function of the module is totranslate signals being sent from the control system toEMDEC, and data traveling from EMDEC back tothe control system.

Engine speed information is communicated from the

control system to the ECMs through an interfaceboard.

Depending on the application, the connection fromthe interface module to the control system may be aone-way or two-way serial data link.

The main difference between the two types of links isin the amount of data that can be transmitted. Theone-way link allows for simple speed instructions fromthe EM2000 to EMDEC, and simple fault messagesand performance feedbacks from EMDEC to the

EM2000. The two-way serial link allows for enhanceddata transmission both ways.

4.4


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4

With the one-way serial link, the ECMs areprogrammed to accept 4 input signals, which are thentranslated into set speeds. Throttle information is sentfrom the control system to the interface module as 0 or74 VDC governor solenoid signals. The interfacemodule translates these 0 or 74 VDC signals intoinverse logic 0 or 24 VDC signals for the ECM's.Consider the following examples:

Example #1 - Throttle in Normal Idle(300 RPM)

Control System Signals Interface Signals

ECM Set Speed

A Valve - 0 VDC A Valve - 24 VDC

B Valve - 0 VDC B Valve - 24 VDCC Valve - 0 VDC C Valve - 24 VDCD Valve - 0 VDC D Valve - 24 VDC

Example #2- Throttle in Run 6(730 RPM)

Control System Signals Interface Signals

ECM Set Speed

A Valve - 74 VDC A Valve - 0 VDCB Valve - 74 VDC B Valve - 0 VDCC Valve - 74 VDC C Valve - 0 VDCD Valve - 74 VDC D Valve - 0 VDC

Speed Control -

One-Way SerialLink (LocomotiveApplication)

SPEED CONTROL

4.5

4.5.1


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The two-way serial link functions much differently forengine speed control. Instead of speed signals sent toEMDEC as governor solenoid signals (signals are stillgenerated for trainline control), EM2000 creates exactRPM requests (for example 1000 RPM), and relaysthese to the ECMs over the serial link. This method isvery fast and decreases the chance of problems in thespeed signals. Note that the two-way serial link passesall communication through the interface panel.

Fault data and load control information are sent backto the control system from EMDEC through theinterface module. These types of data will be looked atin greater detail in later chapters.

In a marine application, control signals are relayed tothe ECMs as a variable speed governor signal. Notethat the signal is supplied to the ECMs as Vref(ECM#ID). As the original voltage is increased, theECMs will translate the reference signal to an RPMrequest.

Power generation applications typically use twoseparate engine speeds only; IDLE (standby) and

Speed Control -Two-Way SerialLink (LocomotiveApplication)

4.5.2

Speed Control -(MarineApplication)

4.5.3

Speed Control

4.5.4


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4EM2000

74 VDC

ABCD

2 WAY

SERIALLINK

ABCD

TIMING & SPEED INFO

FEEDBACKSINJECTORS

9-16

ECM

SENDER

F

P

F T

SRS

TRS

RPM

24 VDC

Request

O P

24 VDCPOWERSUPPLY

LOCOINTERFACE FAULT &

SENSORDATA


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EM200074 VDC

ABCD

74 VDC

ABCD

FAULT DATA

TIMING & SPEED INFO

FEEDBACKS

INJECTORS

9-16

INJECTORS

1-8

ECM

RECEIVER

ECM

SENDER

F

P

F T

SRS

TRS

RPM

24 VDC

Request

A P

A T

O P

O T

C P

CC

24 VDC

POWER

SUPPLY

LOCO

INTERFACE


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4

At this point, the system has been supplied with 24VDC for operation, and has received speed inputsfrom the control system. Before EMDEC can operatethe injectors, additional information is required suchas timing and speed data, engine performance data,

and engine protection data. All this information comesinto the ECMs in the form of sensor inputs. Thesensors can be broken down into three major groups:

1. System Sensors for timing and speedinformation:

Synchronous Reference Sensor (SRS) Timing Reference Sensor (TRS)

2. Performance Sensors for calculating fuel injectoroperation:

Fuel Pressure Sensor (FPS) Fuel Temperature Sensor (FTS) Turbo Boost or Air Pressure Sensor (TBS) Air Temperature Sensor (ATS)

3. Protective Sensors for monitoring ofsupport systems:

Oil Temperature Sensor (OTS)Oil P S (OPS)

SENSORS

4.6


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System Sensors

The system sensors (figure 4.6a and 4.6b)provide twofunctions for EMDEC operation. Timinginformationis used by the ECM's to determine when to energizethe injector solenoids. Speedinformation is used tocompare actual engine speed to desired engine speed.Fuel rates are then adjusted by the ECM's to correct anyvariation. Unlike other sensors on the engine, the systemsensors (SRS & TRS) are magnetic pickups. Operation ofthe system sensors is identical between the 710 and Hseries engines, however the mounting arrangement is

very different.

4.6.1

Figure 4.6a 710 Series System Sensors, Previous Models (Left) Recent Models (Right).


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4

The early 710 series of engines have three timingplates (figure 4.7a)attached to the inside face of thecoupling disk between the engine and ring gear. Theplates have openings cut into them leaving 36 spokesthat are used to generate signals by the TRS sensor.One of the plates has a (Position Indicator Pointer) PIPattached, that is used by the SRS sensor to generatesignals.

SRS and TRS share a common mounting bracket

located on the left rear corner of the engine. Thisbracket serves two functions; first to hold SRS and TRSin precise alignment with the PIP and spokes on thetiming plates; and second, the spring and stopmechanism allows the bracket to swing back and thenreturn to the original position should the coupling disk

flex. This serves to protect the sensors from damagecaused by contact with the timing plates.

System SensorMountingArrangements -Early 710 Series

4.6.1.1


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An improved feature on the 16-710G3C-T2 engine isthe mounting and accessability of the SRS and TRSsensors.

Figure 4.7b SRS and TRS Sensors.

The H series of engines does not use coupling disk

mounted timing plates like the 710. Instead, theseengines have timing disks attached to the front andrear of the camshaft (figure 4.7c). The timing diskshave a circle of 36 raised bumps stamped into them,that are used to generate signals by the TRS sensor.Each disk also has a stamped PIP that is used by theSRS sensor to generate signals. Note that although

there is a disk on each end of the camshaft, only therear plate is used at this time.

System SensorMountingArrangements -H Series

4.6.1.3

Setting SRSand TRS Sensors

4.6.1.2


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4

Timing

Synchronous

ReferenceSensor

SRS and TRS are rigidly mounted in the coverhousing the rear camshaft gear. They are arranged toread the stamped protrusions on the timing disk andrelay this information to the ECM's. Reading camshaftspeed (one half crank speed) allows for the use of thesame ECM's as the 710 series.

The Synchronous Reference Sensor or SRS provides asignal to the ECMs when the Position Indicator

Pointer (PIP) passes in front of it. The action of the PIPpassing in front of the pick-up causes a small current tobe induced in the sensor, which then passes throughthe wiring harness to the ECMs. This signal isprovided once, for every revolution of the crankshaft,and indicates when the number one cylinder is four

degrees before top dead center.

This signal synchronizes the ECMs with respect toengine speed and crankshaft position, this tells theECMs when to start the timing count.

The Timing Reference Sensor or TRS reads the metalspokes of the timing plates. As the engine rotates, the

4.6.1.4

4.6.1.5


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PerformanceSensors

Note that unlike other systems, there are no specifictiming indicators for each cylinder. Instead, the firingorder of the engine is contained in the ECMssoftware. With this type of a system, the same pick-ups,timing plates, and wiring harness may be used with anyengine configuration.

The calculation of engine speed is quite simple. TheECMs simply look at the elapsed time between TRSpulses to calculate engine speed. This is thencompared to the set speed. If actual speed is lower than

set speed, EMDEC will lengthen the injector pulsewidth to add fuel to the engine. If actual speed ishigher than set speed, EMDEC will shorten the pulsesto reduce the amount of fuel injected.

The performance sensors (figure 4.8)provideinformation that is used for adjustment of fuel rates. By

NOTE:

The sensors used as examples in this section are for a

generic 16 cylinder 710 series engine. The feedbacks

portrayed are to be used as examples only as there are

several different models of sensors used in service

depending on specific application. Note also that the

number of sensors used will vary.

4.6.2


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4

EM200074 VDC

ABCD

74 VDC

ABCD

FAULT DATA

TIMING & SPEED INFO

FEEDBACKS

INJECTORS9-16

INJECTORS

1-8

ECM

RECEIVER

ECM

SENDER

F P

F T

SRS

TRS

RPM

24 VDC

Request

A P

A T

O P

O T

C P

C C

P

24 VDCPOWERSUPPLY

LOCO

INTERFACE

PERFORMANCE

SENSORS

Figure 4.8 Performance Sensors.


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The Turbo Boost or Air Box Pressure Sensor (figure4.9)provides data to the sender ECM for use primarilyin emission control. It is also known as the smokesensor. The sensor is connected to the ECM with athree wire plug, and to the engine with a sensing hose

off the left front corner of the engine. The device ismounted just below the crankcase pressure sensor,(early 710 systems), in the sensor box (late 710systems), or on the front of the aftercooler ducts (HEngines).

Figure 4.9 Turbo Boost Sensor.

Turbo BoostSensor (TBS)

4.6.2.1


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4

Figure 4.10 shows a typical feedback graph. Note thatthe device measures absolute pressure and at 0 psi, thefeedback voltage is approximately 0.5 VDC. Note alsothat at 45 psi, the feedback is approximately 4.5 VDC.The ECM looks at this feedback signal for threeconditions.

Boost Pressure SensorP/N 16070629

6

5

4

3

2

1

010 15 20 25 30 35 40 45

SensorO

utput(Volts)

Airbox Pressure (psi)

Check calibration at25 C and Vin = 5.1 VDC

Normal

Error Limits


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In either case, the following happens:

the feedback is ignored for calculations,

a nominal "standard" pressure is used,

a "fault" is generated in the archives specific tothe feedback failure (voltage low or high).

Remember that the fault archive can be accessed byuse of a laptop computer (with WinEMMON or PCReader software), or the FIRE display (two-way serial

link).

The Air Temperature Sensor or ATS (figure 4.11)measures the temperature of the air charge in theengine airbox. This feedback is necessary for fuelconsumption calculations and emission control by theECMs. The sensor is applied to the left front corner ofthe engine next to the turbo boost sensor, with theprobe inside the airbox. On some applications, asecond sensor, inlet air temperature (IATS) has been

applied to the inlet eye of the turbocharger. Thissecond sensor is identical to the Air Temperaturesensor.

Air Temperature

Sensor

4.6.2.2


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4

This sensor is a thermistor type device. As thetemperature changes at the sensor probe, the internalresistance of the device changes. The voltage andcurrent characteristics of the circuit are looked at bythe ECM, and are converted into a temperature

reading.

Temperature Sensor ResistanceP/N 40063567

100,000

10,000

1,000

100

10

0 50 100 150 200 250 300

SensorOu

tput(ohms)

( )

Calibration points:

77 F = > 2590.7-2964.7 ohms

262.4 F = > 77.7-84.9 ohms


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FuelTemperatureSensor

The Fuel Temperature Sensor or FTS (figure 4.13)measures fuel supply temperatures necessary for fuelconsumption calculations, and fuel inputcompensation by the ECMs. This is one of thefunctions that goes beyond the possibilities of the

mechanical system. The fuel temperature sensor is anidentical device to the air temperature sensor(s). It islocated on the secondary fuel filter manifold andexamines the temperature of the fuel as it enters theengine. As fuel temperature increases, performancedecreases. EMDEC will compensate for high fueltemperatures by adjusting pulse width and timing asrequired.

Figure 4.13 Fuel Temperature Sensor.

4.6.2.3


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4

The Fuel Pressure Sensor or FPS (figure 4.14)monitors fuel supply pressure for two reasons. First, thefuel pressure reading is an input to the sender ECMwhere it forms part of the fuel rate calculations.Second, should fuel pressure drop below an

acceptable level, the system will log a fault to warn ofany impending power loss.

Figure 4.14 Fuel Pressure Sensor.

The device is a capacitive pressure transducer.Operation is quite similar to that of the boost pressure

FuelPressureSensor

4.6.2.4


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Figure 4.15 Fuel Pressure Sensor.

Figure 4.15 shows a graph of the sensor output. Note

that the cut off points for feedback voltage areapproximately 0.5 VDC and 4.5 VDC. If the feedbackis maintained within this range, the ECM will

id h i l lid d h f db k f

Pressure Sensor SignalP/N 40059731 or 40087573

5

4

3

2

1

0

0 20 40 60 10080 120 140 160 180 200

SensorOutput(Volts)

Pressure (psia)

Normal

Error Limits

Check calibrationbetween 77 and 221 F

at 5.0 .1VDC


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4

The protective sensors (figure 4.16)provideinformation that is used by the sender ECM to

monitor the performance of the engine supportsystems. In the event of a system failure (lube oil,cooling, or crankcase ventilation), EMDEC can shutdown the engine to prevent costly component damage.The protective functions of EMDEC have beenprogrammed to react in exactly the same manner as a

Woodward governor. All shutdown pressures,temperatures, and timing remain the same as on themechanical system.

PROTECTIVESENSORS

NOTE:

The sensors used as examples in this section are for a

generic 16 cylinder 710 series engine. The feedbacks

portrayed are to be used as examples only as there are

several different models of sensors used in service

depending on specific application. Note also that the

number of sensors used will also vary.

4.6.3


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EM200074 VDC

ABCD

74 VDC

ABCD

FAULT DATA

TIMING & SPEED INFO

FEEDBACKS

INJECTORS

9-16

INJECTORS

1-8

ECMRECEIVER

ECM

SENDER

F P

F T

SRS

TRS

RPM

24 VDC

Request

A P

A T

O P

O

T

C P

C

C P

24 VDC

POWER

SUPPLY

LOCOINTERFACE

PROTECTIVE

SENSORS


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4

Oil PressureSensor

The Oil Pressure Sensor or OPS (figure 4.17)providesa feedback of engine lube oil pressure to the ECM. Ashutdown will occur if the engine lube oil pressure atthe turbocharger drops below a predeterminedsetpoint, relative to engine speed and duration of time.

The oil pressure sensor is an identical unit to the fuelpressure sensors, and is mounted in the top of theturbo lube filter head or on the left front corner of theengine in some applications.The shutdown times andpressures are identical to previous systems.

Figure 4.17 Oil Pressure Sensor.

4.6.3.1


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Oil TemperatureSensor

Physically, the Oil Temperature Sensor or OTS (figure4.18)is identical to the fuel and air temperaturesensors. The input to the sender ECM allows it tomonitor the temperature of the oil entering the lube oilsystems in the engine. An engine shut down will occur

if the oil temperature exceeds 256F (124C). Thesensor is located in the same position as the hot oildetector on the mechanical injection system.

Figure 4.18 Oil Temperature Sensor.

This sensor also has three possible types of faultconditions. Input voltage high or input voltage low willeach generate a separate fault condition. If the signalfrom the sensor is valid (between 0.5 and 4.5 VDC), but

above the operating parameters, a shutdown fault islogged and fuel injection is cut off, stopping theengine. This will prevent damage to enginecomponents caused by excessive oil temperatures.

4.6.3.2


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4

CoolantPressureSensors

The Coolant Pressure Sensors or CPS , monitorcoolant pressure at the water pump discharges, and atthe Y pipe (engine discharge). The sender ECM maybe connected to one, two, or three CPS depending onsystem requirements and engine configuration. A

typical system will use two sensors. The coolantpressure sensors (figure 4.19)are identical units to theoil and fuel pressure sensors. If coolant pressure dropsbelow a programmed set point, an engine shut downwill be initiated.

Figure 4.19 Coolant Pressure Sensor.

4.6.3.3


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CrankcasePressureDetector (CCP)

The Crankcase Pressure Detector (figure 4.20)activates if crankcase pressure increases to a positivepressure of 1 1/2" of water.Unlike other sensors, theCCP is a mechanical

device. The detectorconsists of a sensingdiaphragm, trip button,and electrical switch. It islocated in the samelocation as the EPD onmechanical injectionsystems.

Following a crankcase pressure shutdown do not openi f i i f t h A

Figure 4.20 Crankcase Pressure

Detector.

DO NOT attempt to restart the engine until the cause of

the shutdown has been determined and corrected.

WARNING:

4.6.3.4


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4

The mechanical portion of the device must bequalified on maintenance inspections to ensure properoperation. Consult section 13 of the EMM for testprocedures.

The crankcase pressure sensor has been developed toreplace the crankcase pressure detector. It is located inthe sensor box on the left front corner of the engine(figure 4.20). Unlike other pressure sensors this devicecan read both positive and negative pressures. Engine

protection parameters and responses remain the sameas the CCP.

This completes the section on electronic componentsof the EMDEC system. The following chapters willdeal with load control, fault data, troubleshooting, anddiagnostic tools.

CrankcasePressureSensor

4.6.3.5


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Notes:

Load


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5

The term load control refers to the matching ofelectrical load on the main generator to engineperformance. In one way, this may be considered as

another protective system for the diesel engine. If thereis a problem with the engine that will reduce availablehorsepower, such as plugged air or fuel filters, it isnecessary to reduce the load on the engine to preventdamage to components or over-fueling. Over-fuelingleads to unacceptable levels of exhaust emissions andpossible engine damage.

Control of the actual load on the generator, commonlyreferred to as excitation level, is the responsibility ofthe locomotive control system. The injection system

must provide the control system with a feedback thatwill indicate the engines ability to maintain speed atthe given load level.

This section of the text will look at this feedback, howit is generated, and how it is used by the control system

to modify the load.

Load control with EMDEC protects the dieselengine against overloading and overfueling

Control

INTRODUCTION

5.1


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The operator establishes a desired power level usingthe control system (figure 5.1). The control systemdetermines excitation levels and engine speeds. Thecontrol system speed relays commands to EMDEC,EMDEC, through the interface module.

Once the ECMs receive the signal from the interfacemodule, this is converted to a set speed. As we saw inthe previous chapter, the ECMs will control the fuelinjectors based on sensor inputs, to maintain actualengine speed at the set speed level.

SET

SPEED

SET

SPEED

CONTROL CONSOLE EM2000

COMMUNICATIONS

PORT

THROTTLEHANDLE

THD1 THRU 8

INTERFACE MODULE

EMDEC HASITS OWN

ISOLATEDGROUND

24V SYSTEM

LOAD OUTPUTDIGITAL SIGNAL

(ONE WAYSERIAL LINK)

EMDECSENDING MASTERECM (SENDER)

SERIAL LINKFUEL PULSE WIDTH TO EUI INJECTORS


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5

FUEL MAPS

5.2 Fuel maps are programmed into the ECMs software(figure 5.2), that indicate allowable pulse widths foreach throttle position. Remember that the injectorpulse widths refer to the duration of the injectionpulse, measured in degrees of crankshaft rotation. The

longer the pulse width, the more fuel is injected intothe engines cylinders.

As we see in the below, there is a different map foreach throttle position. These are examples only;actual maps vary according to application. For

example, in throttle 5, an allowable pulse width forinjection would be anything from 0to 15. In throttle8, any pulse width between 0and 23may be used bythe ECMs. The fuel maps indicate the total availablefuel for each throttle position.

2

IDLE OR 1

Throttle

Position

3

4


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CONTROLLING

ENGINE SPEED

5.3 EMDEC works just like a Woodward governor tocontrol engine speed. If speed drops, it adds fuel(opens the injector pulse widths). If speed rises, it cutsfuel (closes the injector pulse widths). A feedback tothe control system is still required to prevent overfueling.

EMDEC will generate a reference signal proportionalto the amount of fuel being consumed (figure 5.3).

In the above illustration, we see examples of the fuel

maps for throttle 5 and throttle 8. As EMDEC operatesthe injectors, it generates the Engine Ratio signal. Thisis the actual pulse width divided by the maximumpulse width expressed as a percentage Simply put the

Throttle

Position

PULSE WIDTH

(Degrees of Crankshaft Rotation)

PULSE WIDTH

(Pulse Width Degrees...)

5

8

0 11.5 21.5 23

15117.5

100%87%50%0%

100%50% 87%

0

Figure 5.3 Engine Ratio Signal.


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5

Normally, if everything is operating properly underload conditions, the engine will require approximately78% to 80% of the total available fuel. Actualconsumption will vary according to engine and ambientconditions. For example, in Load Test 1, the engine

typically will use a pulse width of about 18.5inthrottle 8. This would equate to an engine ratio signalof approximately 80%; it is consuming 80% of the totalavailable fuel in throttle 8. Should there be any problemswith the engine, for example plugged air filters,performance will drop, and EMDEC will have to addmore fuel to the engine to maintain speed against theload on the generator. As the pulse width is openedby the ECMs, the Engine Ratio signal increasesproportionally.

The Engine Ratio signal is sent to the EM2000 via theinterface module, and the serial data link. By lookingat this signal, the EM2000 can assess the enginesability to make horsepower. As long as the EngineRatio is less than 87%, the EM2000 will assume thatthe engine can make full power, and will regulate

generator excitation to produce the proper kilowattoutput for the throttle position.

However should the Engine Ratio rise to 87% for any


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Notes:


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5

Notes:


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DiagnosticTools


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6

DiagnosticTools

INTRODUCTION

6.1 This section of the text covers the use of diagnostictools to access the EMDEC ECMs. These tools arerequired for troubleshooting, loading software, and

injector calibration. Covered, are procedures for usingthe WinEMMON or PC Reader program with alaptop computer and the FIRE display for applicationsequipped with a two-way serial link.

Note that EMDEC is an evolving system that isconstantly being upgraded to improve servicereliability and performance. Every effort has been hasbeen made to ensure that the information containedin this section is current, however, always consult theproper system schematics and EMM for specific

service data.

The WinEMMON kit (figure 6 1) is the recommended6 2


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The WinEMMON kit (figure 6.1) is the recommendedEMDEC interface tool. Some locations will have theolder PC Reader system as a diagnostic tool, so this willbe covered as well. The primary difference between thetwo system diagnostic tools is that WinEMMON is a

Windows based system while PC Reader is based onthe older DOS (Digital Operating System) technology.

The following instructions are provided to assist thetroubleshooter in using this tool. The PC reader enablesyou to:

monitor all sensor inputs to the ECMs;

view ECM outputs to the injectors (pulse width and timing);

view injector response times;

calibrate the injectors;

load ECM software;

view and download fault data.

The software generates a diagnostic screen and interface

protocol on the laptop. To use the program, it must beloaded into the laptop, the laptop connected to theEMDEC system through the cable and translator

bl d h d h f ll

WINEMMON &PC READER(DIAGNOSTICSWITH A LAPTOP

PC)

6.2

WinEMMON and PC Reader are software programs6 2 1


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WinEMMON and PC Reader are software programsthat are run on a personal computer interfaced withthe EMDEC system. It is recommended that

WinEMMON be used in a laptop PC running aWindows 95 operating system or newer, such as

Windows 98, 2000, NT, XP, or XP PRO. You willalso need the WinEMMON Diagnostic Kit(#40094241), which consists of the following:

WinEMMON Translator Box #40094242

WinEMMON Software Disk #40094243 15 D-R Plut #40055365

PCT-R Cable #40055364

9 Pin Male to 9 Pin Female Cable #40055366

PC Carry Case #40055367

The minimum requirement for using PC Reader is a386SX/DX-type laptop with one megabyte of RAM.In addition, the PC Reader kit (#40055368),

consisting of the following items, is required:

EMDEC Translator Box #40055363

Using theWinEMMON orthe PC Reader Kit

6.2.1

6.2.2 1 Insert disk #1 of the WinEMMON


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LoadingWinEMMONSoftware On To ALaptop Computer

6.2.2 1. Insert disk #1 of the WinEMMONsoftware (#40094243) into the floppy diskdrive of your laptop computer (usuallythe A: drive).

2. Click on the Start button in the lower leftcorner of your computer screen.

3. When Run appears above the Startbutton, click on Run.

4. When the command box opens, type inA: setup, without the quotations marks,then put the mouse on OK and click it.

5. The computer will then copy theinitialization files required from disk #1.

When that is done, the computer will tellyou to insert disc #2.

6. Remove disk #1 from the floppy driveand insert disk #2, then click on the ok

button.

7. This will allow the setup program toproceed Close any other programs you

8. Next you will be asked where you would


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6

8. Next you will be asked where you wouldlike the WinEMMON directory to beplaced on your computer. The defaultlocations is Program Files on the C:drive. If you wish to put your WinEMMON

program somewhere else on your computerthan the default choice (not recommended),click on the Change Directory button andfollow the instructions that appear. If you aregoing to use the default location (recommended),then click on the large box in the upper left of the

pop up box (it has a computer icon on it).

9. The computer will now copy the WinEMMONfiles to the chosen directory. When the computertells you that the installation has beensuccessfully completed, click on the OK button.

You have now successfully installed WinEMMON onyour computer. Connection and diagnostics use willbe covered later in this chaper.

1. Escape out of Windows and get to the C:\>6.2.3


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p t g t t tprompt. It is imperative that windows not beactive, or the program will not function as desired.Press Alt+F4 or double click the cursor on theupper left bar on the windows screen to exit

Windows.

2. Create a new directory (For example:C:\> md emdec).

3. Change the directory to the pcreader

(For example: C:\> cd emdec).

4. Once in the directory, copy the files fromthe disk into the directory (For example:C:\emdec> copy a:\*.* ).

Occasionally the PC Reader software is upgraded toenhance its operation, or to reflect changes in theequipment installed on the engine. After receiving anew version of PC Reader, it will be necessary tochange the files in the laptop. To ensure properoperation, use the most recent software.

Loading The PCReader SoftwareOn To A LaptopComputer

1. While in the EMDEC directory, type in:6.2.3.1


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y, ypedit emmon.bat. A screen will appearshowing the contents of the emmon file.

Example: @ECHO OFF

rp1202emmon11a (or currentversion number)ECHO ON

2. Use the cursor to select the existing

executable file (For example emmon11aor current version number), and renameit to the latest executable file nameloaded (such as emmon11a).

3. Press Alt + F to highlight the File task

bar, and open the dialog box.

Select SAVE and press .

4. Press Alt + F to highlight the File taskbar and open the dialog box once again.

Select EXIT to return to theemdec directory.

To Edit TheEMMONCommand File

On most applications there are two access locations for6.2.3.3


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EMDEC (figure 6.2).

One is located in the cab of the locomotive, inside thecenter door of the Computer Chassis Cabinet. The

EMDEC access port is located to the right of theEM2000 computer chassis, and is labeled EMDEC.

The second access port is located on the interfacemodule mounted to the 24 VDC power supply. It isusually found in the AC Cabinet in the EngineCompartment.

Access Ports

80 SERIES / 90 SERIES

AC CabinetHigh Voltage CabinetEMDEC Ports


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6

ElectricalLocker

Figure 6.3 EMDEC Access Port (SD70ACe/ SD70M-2).

1. Connect the 9 Pin cable from the PC to6.2.4


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the translator box.

2. Connect the 15D-R plug to the PCT-Rcable, and the other end of the cable tothe translator box.

3. Connect the 15D-R plug into the EMDECreader port, and note that both the red and greenLEDs on the side of the translator box areilluminated.

The EMDEC Communications (EMMON)program will not work if the hardware is notconnected to the locomotive.

4. Click on the Start button in the lower leftcorner of the computer screen. When the menu

options appear, click on all Programs/Programs(depending on which version of Windows youare using). Move the cursor (arrow) to the

WinEMMON option, and click there. ForPC Reader change the directory on the PC toC:\emdec> and type EMMON to startthe program.

A message will appear stating that the program is

UtilizingWinEMMON &The PC ReaderProgram


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6If the software is loaded correctly, and the system isproperly connected, a main screen should appear onthe laptop (figure 6.4).

The systems (EMDEC, WinEMMON or PC Reader),

are communicating when the green light on thetranslator box is illuminated, and the red light isflashing. If there is a problem with the connection,another message box will appear (figure 6 5) This

Figure 6.4 Communication Problem.


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Figure 6.5 Communication Problem.

The main WinEMMON screen consists of fivesections, covering Sender ECM, Receiver 1 ECM, and

Receiver 2 ECM. As well, there are sections forTranslator Box and System Description. In the lowerright corner of the Main Screen is a refresh button.The ECM sections give you the software part number

WinEMMON

Main Screen

6.2.5


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6Figure 6.6 WinEMMON Main Screen.


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Figure 6.7 System Information Dialog Box.

The WINEMMON main screen appears wheneveryou open the WinEMMON program, regardless ifyou are connected to the locomotive. The SystemInformation Dialog Box (see Figure 6.7)will thenappear on the computer screen This will document


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6Figure 6.8 System Information Dialog Box.If the connection is successful the System InformationDialog Box will show the connection data (see Figure

6.8).


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Figure 6.10 Windows Translator Box Help Screen.

This Communication Error box will give you threeoptions, Retry, Cancel, and Help. Retry tells the systemto attempt to communicate with the locomotive again.Cancel will stop the whole process and close the

WinEMMON program. Help is a shortcut to theWinEMMON Help program, in particular the sectionon Translator Box connections, that gives a diagram ofthe proper connections and a description of same (see


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Figure 6.11 WinEMMON Main Screen (System Information)

This Help screen describes the two lights on theTranslator Box and gives some helpful suggestions tocorrect any connection problems you may encounter.

If the connection was successful, the WinEMMONMain screen will appear (see Figure 6.11). Across thet f th th ti l ti b tt


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6Figure 6.12 WinEMMON Main Screen (System Information).

On the left of the System Information Screen there are

three sets of ECM information fields. The sets of dataare labeled, from top to bottom:

S d ECM

ECM Data

6.2.5.1

The information in these fields shows:


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The software part number The software revision number The calibration name revision

This will be useful data when determining if thesoftware loaded into the ECMs is correct for theapplication. The data in these fields serves one otheruseful function; having the data in the fields serves toconfirm that the ECMs are communicating correctly

with WinEMMON.

On the right hand side of the screen are three otherdata fields. The two in the upper right hand corner ofthe screen are for the Translator box. These fields

show:

Status of the Translator Box (connectedor disconnected)

Version of the Translator Box being used

This data will help to trouble shoot a connectionproblem to determine if the fault lies within the physical

Secondary Data

6.2.5.2

The field in the lower right hand side of the screen isfor system information, that is which engine/wiring


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6

y g gcombination is used on that particular engine. Belowthat is the Refresh button, which will replace the datawith fresh data whenever clicked on.

If you move the computer cursor (usually an arrow) tothe top of the screen and on to the Monitor button,then click on it (on the keyboard of the computer,usually close to the mechanism for moving the cursor,will be two buttons. The left of these buttons will

usually be the selector button that you press, or click,to make your selection. The mechanism for movingthe cursor will usually be a small pad that you dragyour finger across, known as a touch pad, or a smallbutton called a pointer) the Monitor screen willappear, see Figure 6.13.


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Figure 6.13 Monitor Screen.

The Monitor screen allows the operator to look at, ormonitor, engine functions in real time. All sensorfeedbacks monitored by EMDEC can be monitored.These include engine speed, engine RPM set point,engine R (as shown), as well as such things as temperaturesand pressures. The signals (known as parameters) shown in

Figure 6.13 are the default signals that are loaded whenyou first open the monitor screen. Other parameters canbe selected by moving the cursor to the Select Parametersb tt i th l i ht h d id f th d

Monitor Screen

6.2.5.3

Once the desired parameters have been selected, move thecursor to the Save button and click on it if those parametersselected are the parameters the operator wishes to keep


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6

selected are the parameters the operator wishes to keepusing. Note that the parameters can be changed at anytime, as required.

There are two signals that are extremely valuable fortroubleshooting. The first one is Engine Ratio, that wasdiscussed in the Load Control Section. It is the bottomline of the box and is labeled as "% max fuel".The second signal is labeled "% allowable torque".

If EMDEC is satisfied with the performance sensorinputs (fuel temp, fuel pressure, air temp, and airpressure),it will maintain this signal at 100%.

If EMDEC itself must cut back on horsepowerbecause of an engine performance problem (such as

low boost pressure), this signal will be reduced.

Reducing the allowable torque signal has the effect oflowering the top ends of the fuel maps. This in essencewill increase the Engine_R signal to the EM2000,causing it to reduce generator excitation.

Remember the three signals.


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Figure 6.14

Data Save Box.

A Snapshot of data can be taken and saved by movingthe cursor to the Save button and clicking on it. ASave box then opens (see Figure 6.14), requiring theoperator to name the data file (unit number, date, or

other relevant information that identifies the datashould be used) and then move the cursor to theOpen button and click on it. A second Save box

Saving Data

6.2.5.4


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6

Figure 6.15 Diagnostics Screen.

If the operator then moves the cursor to the top of theMonitor screen and places it on the Diagnosticsbutton, and clicks on it, the Monitor screen will closeand the Diagnostics screen will appear (see Figure6.15).

The Diagnostics screen is a Real time display ofcurrent faults both active and inactive from the

Diagnostics

6.2.6

For example, in Figure 6.15, the Diagnostics screenshows us that there are no Active Faults. UnderInactive Faults Proprietary Data Link is displayed

UnderstandingThe Fa lt Screen

6.2.6.1


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Inactive Faults, Proprietary Data Link is displayed.This tells the operat

EMDEC troubleshooting tool

Documents