Kn ppt aum221 1 1 intro basics

Engine PerformanceBasic Electronics

and Computer

Systems

Computers can be called

central processing unit

powertrain control module

engine control module

body control module

transmission control module

controls body systems

controls transmission & traction

controls engine & transmission only

controls all electronic system

Generally for our learning purposes, we’ll group them all as one

C P U

E C M

P C M

T C M

B C M

controls engine systems

Computer Functions

• Input– Is a signal sent from an input device.

• Processing (logic)– The computer compares input information to programmed instructions.

• Storage– The programmed instructions are stored in the computer’s memory.

• Output– Is a command given by the computer to operate an output device.

at INPUTS firstLet’s

• All inputs have same basic function

detect a mechanical condition, position, chemical state

temperature, or electrical value

change it into an electrical signal to be used by a computer.

INPUTS can be either

Switches

Sensors

or

something turned on or offeither by a person, or a device

switches are either normally open or normally closed

they send an digital input signal to the pcm

some switches switch the ground side some switch the power side

if they switch power, it can be B+ or Reference Voltage

Switches

Switches

P S P Power Steering Pressure Switch

OD Overdrive Switch

CP Clutch Pedal Position Switch

I G N Ignition Switch

P N P Park Neutral Switch

B L S Brake Light Switch

A C C A/C Clutch Switch

T S Temperature Switch

Sensors

• Each sensor has a specific job.

• All sensors are either

reference voltage sensors or

voltage generating sensors.

provide feedback information

✓confirms position or action

✓reports voltage changes

(instead of on / off)

Various Sensors

C T S Coolant Temperature Sensor

A T S Air Temperature Sensor

T P S Throttle Position Sensor

I S C Idle Speed Control Sensor

C R K Crankshaft Position Sensor

M A P Manifold Absolute Pressure Sensor

KNOCK Sensor

E G R Position Sensor

M A F Mass Air Flow Sensor

C A M Camshaft Position Sensor

Oxygen Sensors

One Wire

Two Wire

Three Wire

Four Wire

• All sensors are either reference voltage sensors or voltage generating sensors.

Remember this statement ?

Notice..... they all have to do with voltage

They must either create their own voltageor respond to the battery voltage

Let’s Talk AboutReference Voltage Sensors

“use of a source of information in order to ascertain something”

Reference means

What are we “referencing . . . . and why ?

Remember this is

“Reference Voltage”

All we have to work with is the vehicles voltage

A good battery supplies 12.6 volts

A weak battery will supply less

A good charging alternator can supply 13.5 - 14.5 volts

A bad alternator can supplyvoltage above 14.5 volts

or no volts at allleaving you with

battery voltage that is decreasing

Since we are “measuring”or “referencing” something

there must be a point where that measurementis always the same

A car simply won’t runif the voltage drops below

6 Volts

So............to solve this problem

The computer sends a constant5 volts

to the sensor

That way it can’t be confused with any voltage generated by something other than

what the computer sends out

And it provides a constant pointto measure from

For all of the sensors that need to measureor “reference” voltage

“reference”

5volts

Reference Voltage Sensors

• Computer sends a constant voltage to the sensor.

• The sensor reacts and sends a voltage signal back to the computer.

• Reference voltage is normally 5 to 9 volts.

• Most are variable resistors or potentiometers.

So......... inputs can be

Switches

Reference voltage feedback sensors5

volts

On or Off

Voltage Generating Sensorsthey make their own voltage signal

OR

Voltage Generating Sensors

• Speed sensors

• Hall-effect switches

• Oxygen sensors

• Produce an input voltage for the control system

• Knock sensors

Magnetic Pulse Generators• Also called permanent magnet generators.

• Use magnetic induction.

How do they produce voltage ? ?

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Current running thru a wire wound around a solid core

Hall-Effect Switch• Performs the same function as a PM generator





at OUTPUTS nextLet’s

Actuators

• Solenoids, • Switches, • Relays, • Motors.

• Electromechanical devices.basically

Solenoids

What is a solenoid ?

A coil of wire, wound tightlyaround a metallic core,

which produces a magnetic fieldwhen an electric current is passed through it.

They can create a controlled magnetic fieldand can be used as electromagnets

Simplified ControlBeing a pulsed device with minimal components optimizes solenoids for digital control. This results in faster cycling and higher reliability with fewer interfaces.

Uncompromising ReliabilitySolenoids provide repeatable, predictable performance with a specified life of up to 100 million cycles.

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Starter solenoid

Trans shift solenoid Fuel injector solenoid

Idle air control solenoid

EGR solenoid

Door lock solenoid

Fuel Solenoid

Throttle solenoid

Variable Valve solenoid

Relays

Relays are remote control electrical switchesthat are controlled by another switch

Horn SwitchSwitch #1

Switch #2

Horn Circuit

A switchcontrolled by

A switch



Many relay show their diagram

Pay close attention

Motors

An electric motor is an electromechanical device that converts

electrical energy into mechanical energy





Endpart 1

Kn ppt aum221 1 1 intro basics

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