13 P1 Traction and Stability Control Internet

7/24/2019 13 P1 Traction and Stability Control Internet

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Table of Contents

E46 TRACTION AND STABILITY CONTROLSYSTEMS

Subject Page

MK20 EI ASC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4C orner Braking C ontrol (C B C ). . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Electronic B rake Proportioning (EB V). . . . . . . . . . . . . . . . . . . . . . 6

D iagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

DSC III MK20. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7System O verview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

D SC C ontrol O verview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

C om ponents

C ontrol M odule/H ydraulic U nit. . . . . . . . . . . . . . . . . . . . . .11

W heel Speed Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . .12

B rake Light Sw itch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

B rake Fluid Level Sw itch. . . . . . . . . . . . . . . . . . . . . . . . . .13

D SC B utton. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Steering Angle Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . .14

C AN Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15R otation R ate Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Lateral Acceleration Sensor. . . . . . . . . . . . . . . . . . . . . . . .17

I.P.O .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

H ydraulic System C om ponents

C harge Pum p. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

M aster Cylinder/Fluid R esevoir. . . . . . . . . . . . . . . . . . . . . .20

Pressure Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

D SC H ydraulic O peration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

D iagnosis. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

TEVES DSC III MK60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Purpose of the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

I.P.O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

System C om ponents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

C ontrol unit/H ydraulic unit . . . . . . . . . . . . . . . . . . . . . . . . 27

C AN Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Tandem M aster B rake C ylinder. . . . . . . . . . . . . . . . . . . . . 30


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Subject Page

Expansion Tank and B rake Fluid Level Sw itch. . . . . . . . . . .30

B rake Pressure Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . 31

W heel Speed Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . .32R otation R ate Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . 35


Transverse Acceleration Sensor. . . . . . . . . . . . . . . . . . . . .37

D SC B utton. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

Instrum ent C luster W arning Indicators. . . . . . . . . . . . . . . . 39

Principle of O peration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

AB S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40

ASC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44

D SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

W orkshop H ints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55

Bosch DSC III 5.7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57Purpose of the System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

I.P.O . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59

System C om ponents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60

C ontrol unit/H ydraulic unit . . . . . . . . . . . . . . . . . . . . . . . . 61

C AN Interface. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62

Tandem M aster B rake C ylinder. . . . . . . . . . . . . . . . . . . . . 63Expansion Tank and B rake Fluid Level Sw itch. . . . . . . . . . .63

Pre-charge Pum p. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

B rake Pressure Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . 64

B rake Light Sw itch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

W heel Speed Sensors. . . . . . . . . . . . . . . . . . . . . . . . . . . .65

Integrated R otation and Transverse Acceleration Sensor. . .67


D SC B utton. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Instrum ent C luster W arning Indicators. . . . . . . . . . . . . . . . 69

Principle of O peration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70AB S. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70

ASC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74

D SC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77

W orkshop H ints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

Traction and Stability Control Systems Application Chart. . . . . . . . 85

Review Questions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86


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MK20 EI ASC

Model: E46/4

Production Dates: 6/98 to 6/99

Objectives

After com pleting this m odule you should be able to:

Identify the com m unication link betw een A SC and D M E.

U nderstand the C B C function of ASC .

U nderstand the EB V function of ASC .


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MK20 EI ASC

ASC w as standard equipm ent on both the 1999 323i and 328i M odels. The Teves -

M ark 20 EI system is used for the E46. The theory/operation of the slip control system is

unchanged from the previous ASC system . The m ajor changes of the M ark 20 El are:

The electronic control m odule is integrated into

the hydraulic unit.

The throttle reduction operation is carried out

through the D M E activation of the M D K m otor.

The ASC control m odule com m unicates w ith the AG S and D M E control m odules over

the C AN B us.

4E46 Traction and S tab ility Control System s


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The M ark 20 EI system includes the C ornering B rake C ontrol (C B C ) utilized in the B osch

ASC 5 system . This feature reduces pressure build-up on the inside rear brake circuit

w hile cornering, if the threshold values for activation are exceeded.

5E46 Traction and Stsbility C ontrol System s


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ELECTRONIC BRAKE PROPORTIONING (EBV)

A new feature of the M ark 20 EI system is the Electronic distribution of the braking force

(EB V). This feature w ill adjust the braking force to the rear w heels based on the vehicles

loading to m axim ize the braking force at all w heels.

The control m odule m onitors the w heel speed sensor inputs, w hen the brakes are applied,

to determ ine vehicle loading. The control m odule com pares the rate at w hich the front and

rear axles are slow ing dow n.

If the rear axle is slow ing at a rate sim ilar to the front it indicates that the vehicle is loaded

and m ore braking force can be applied to the rear calipers to stop the vehicle.

If the decel rate of the rear w heels is far less than the front, it indicates a lightly loaded vehi-cle. At this point, if the sam e braking force w ere applied to the front and rear axles, the vehi-

cle w ould becom e unstable.

If this difference exceeds the threshold values program m ed in the control m odule, EB V is

activated. The control m odule w ill cycle the inlet valves to the rear brakes to regulate the

braking force.

DIAGNOSIS

D iagnosis of the slip control system is carried out w ith the D IS or M oD iC using the faultsym ptom driven troubleshooting procedures.

6E46 Traction and Stability C ontrol System s


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DSC III MK20

Model: E46 all versions except all-wheel drive

Production Dates: 6/99 to 9/00

Objectives


List the com ponents used in the D SC III system .

Explain the intervention the D SC III can execute to control oversteer or understeer.

D escribe the calibration required w hen replacing a steering angle sensor.

Explain the reason w hy a pre-charge pum p is necessary.


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INTRODUCTION

The D SC III system w as introduced for the E46, beginning w ith M odel Year 2000 produc-

tion (E46/2: 6/99, E46/4: 9/99). The system is sim ilar to the D SC III used on the E38 and

E39 vehicles, how ever it is m anufactured by Teves for use in the E46.

The system incorporates all of the features of the previous Teves slip control system and

adds the lateral dynam ic control of the D SC III system already installed on the E38/E39s.

The Teves D SC system is designed to m aintain the lateral locating forces for the follow ing:

AB S braking control

ASC +T traction control

D SC - D ynam ic S tability C ontrol for oversteer and understeer conditions

SYSTEM OVERVIEW

The E46 D SC III system consists of the follow ing com ponents:

C ontrol m odule/H ydraulic U nit (com bined)

Four w heel speed sensors

C harge pum p

Tandem B rake M aster C ylinder

Steering Angle S ensorYaw R ate Sensor

Lateral Acceleration Sensor

Tw o B rake Pressure S ensors

Brake Fluid Level Sw itch

D SC B utton

D SC W arning Indicator

C AN Interface (D M E/AG S)


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9E46 Traction and Stability co ntrol system s

DSC CONTROL OVERVIEW

The Teves D SC system m aintains the lateral location forces during all phases of operation

through;

AB S - H ydraulic intervention preventing the w heels from locking during hard brak-

ing

ASC +T - Engine drive torque reduction and/or hydraulic intervention on the drive

w heels to ensure straight line traction (acceleration - driving and deceleration)

D SC - Engine drive torque reduction and/or hydraulic intervention on any w heel

brake during cornering to m inim ize oversteer and understeer conditions

D SC control can aid the driver in controlling the vehicle w hile driving but can not overcom e

the law s of physics if the vehicle is being driven beyond the range of D SC control.

UNDERSTEER/OVERSTEER CONDITIONS


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COMPONENTS

CONTROL MODULE/HYDRAULIC UNIT

The control m odule is installed in the engine com partm ent, on the right side, in the battery

w ell.

B oth the control m odule and the hydraulic unit are replaceable as separate com ponents.

All processing functions for AB S/ASC or D SC regulating functions are carried out in the one

control m odule. The m odule is linked to the C AN bus for com m unication w ith the D M E and

AG S control m odules. Additionally the C AN bus is used for com m unication w ith the steer-

ing angle sensor and for illum ination of the A B S and D SC indicator lam ps in the instrum ent

cluster.

The hydraulic unit consists of the follow ing:

Four inlet solenoids

Four outlet solenoids

Tw o changeover solenoids

Tw o charge solenoids


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WHEEL SPEED SENSORS

The E46 D SC III system uses the sam e inductive w heel speed sensors from the ASC

system .

BRAKE LIGHT SWITCH

The brake light input signal is used by the control m odule to interrupt an ASC regulation

control if the driver steps on the brakes during its operation.

This interruption does not take place during D SC regulation.


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BRAKE FLUID LEVEL SWITCH

Fluid level sw itch is incorporated into the brake m aster cylinder reservoir. If the fluid level is

correct, the sw itch provides a ground signal to the D C S control m odule.

If the fluid level drops below the specified level, the sw itch opens and the A SC /D SC func-

tions are sw itched off.

DSC BUTTON

The D SC system com es on every tim e the vehicle is sw itched on. The D SC button can be

used to sw itch the system off. The w arning indicator lam p com es on w hen the system is

m anually sw itched off


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STEERING ANGLE SENSOR

The steering angle sensor is m ounted at the bottom of the steering colum n, in front of the

flexible coupling. It utilizes tw o potentiom eters to determ ine steering angle and the rate of

steering change. These signals are processed in the steering angle sensor and a digital out-put signal is passed over the C AN bus to the D SC control m odule.

The sensor requires calibration after repairs to the steering or suspension system . The sen-

sor is calibrated using the D IS or M oD iC . O nce calibrated, the sensor sends an ID num ber

to the D SC control m odule. The ID provides confirm ation to the m odule that the angle sen-

sor is properly calibrated.

Installing a new sensor or exchanging sensors w ith another vehicle w ill require that this cal-

ibration procedure is carried out.


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CAN INTERFACE

The D SC control m odule com m unicates over the C AN line for the follow ing:

Steering angle from the steering angle sensorEngine control m odule for engine intervention

Transm ission control m odule for shift intervention

Instrum ent cluster for illum ination of the w arning indicator lam ps


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ROTATION RATE SENSOR

The rotational rate sensor is m ounted under the driver's seat. It provides a signal to the D SC

control m odule that corresponds to the vehicle's rotational speed around its axis (yaw

speed).

The sensor receives its operating pow er (5 volts) from the D SC control m odule and pro-

vides an output voltage of approx. 0.25 to 4.65 volts depending on the am ount of yaw

exerted on the vehicle.

The sensor operates on the C oriolis effect to produce the output voltage. The elem ent of

the sensor is a m icrom echanical double quartz tuning fork. A frequency of 11 H ertz is

applied to one side of the fork and as the vehicle turns on its axis, vibrations are induced

into the tips at the other end.

The sensor processes the signals produced by the fork and produces an analog voltage

signal that is proportional to the am ount of yaw .

B ased on the control m odule's program m ing param eters, the D SC w ill activate a D SC reg-

ulation cycle to ensure that the vehicle rem ains stable under all driving conditions.


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LATERAL ACCELERATION SENSOR

The lateral acceleration sensor is m ounted in the left "A" pillar. The sensor provides the D SC

control m odule w ith an input signal that corresponds to the degree of lateral acceleration

("G " forces) acting on the vehicle.

The sensor is a capacitive type w ith tw o capacitive plates (one fixed and one m oving).

U nder the effect of lateral acceleration, the one plate m oves in relation to the fixed plate.

This results in a voltage signal being produced in proportion to the degree of lateral accel-

eration.

The voltage signal output of the sensor to the D SC control m odule ranges from 0.5 to 4.5

volts. W hen the vehicle is stationary, The standing voltage from the sensor is approxim ate-

ly 1.8 volts.

This signal is used in conjunction w ith the yaw sensor input to determ ine the degree of D SC

regulation required to m aintain the vehicle's stability.


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HYDRAULIC SYSTEM COMPONENTS

PRE-CHARGE PUMP

The pre-charge pum p is installed betw een the m aster cylinder and the brake fluid reservoir.

D uring D SC controlled regulations that involve brake intervention, the pum p ensures that

the required volum e of fluid is available for the hydraulic unit.

W hen activated, the pre-charge pum p draw s fluid from the reservoir and delivers it to the

m aster cylinder at a pressure of 10 B ar.


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MASTER CYLINDER/FLUID RESERVOIR

The m aster cylinder contains the central valves in both the front and rear brake circuits,

Sim ilar to the B osch D SC system . The central valves allow fluid to transfer during D SC con-

trolled interventions.

The brake fluid reservoir has internal baffles that m inim ize fluid foam ing during controlled

interventions. The charge pum p pick up is m ounted low on the reservoir to prevent air from

entering the system during regulation. The fluid level sw itch w ill signal the control m odule to

cancel D SC regulation if the fluid is below the safety m argin level.

PRESSURE SENSORS

Tw o pressure sensors are installed on the m aster cylinder in the outlet ports for the front

and rear brake circuits. The sensors provide the D SC control m odule w ith an analog volt-

age signal in proportion to the brake pressure in the m aster cylinder.


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DSC HYDRAULIC OPERATION

B ased on the program m ing of the D SC control m odule, hydraulic intervention can be acti-

vated at any w heel brake as follow s:

AB S regulation for any w heel that is in danger of locking - causing the w heel to

skid.

ASC regulation for either or both rear w heels to ensure that the optim um traction

is applied to the drive w heels

D SC regulation for any w heel to correct for dynam ic forces that are causing the

vehicle to becom e unstable. The D SC intervention only takes place on one w heel

of a corresponding axle.

D epending on the hydraulic intervention required, the charge pum p, return pum p, change

over valves, charging valves, inlet and outlet solenoids are activated to provide:

Pressure build up for brake application

Pressure hold to slow or stop the w heel

Pressure release to allow the w heel to turn


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DIAGNOSIS

Troubleshooting the E46 TEVES D SC system is carried out using the D IS or M oD iC .

The fault indicators in the instrum ent panel w ill illum inate w hen there is a fault and the sys-tem is off line.

Follow the diagnostic procedures as outlined w ith the tester to troubleshoot the E 46 Teves

D SC system .


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TEVES DSC III MK60

Model: E46 (except M3 and Xi) and E36/7

Production Date: From 9/00

Objectives


Identify the changes of the M K 60 over the previous M K20EI system .

U nderstand the operation of the new w heel sensors.

Review the operating principles of AB S, ASC and D SC .

D escribe the new AD B and D B C functions.


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Purpose of the system

D SC III M K60 is supplied by C ontinental Teves and supersedes the Teves D SC III M K20 EI

system . The M K60 includes all of the features of the previous M K20 EI system and incor-

porates tw o additional functions:

D B C function

M odified A D B function

The most important changes from the MK20 EI are:

Reduction in size of the control unit/hydraulic U nit.

Installation of the hydraulic unit close to the m aster cylinder.

Elim ination of a pre-charge pum p.

M agneto resistive w heel speed sensors.

The Teves MK60 system is designed to maintain the vehicles stability during:

ABS braking regulation

ASC +T traction control

D SC for oversteer and understeer control

Additional features are also program m ed into the control m odule to enhance driver safety

and com fort. These features are:

C B C C orner B rake C ontrol

EB V Electronic B rake Proportioning

M SR Engine D rag Torque R egulation

D B Autom atic D ifferential B rake

D B S D ynam ic B rake System


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30KL 30

15KL 15

15KL 15

C WITCHDSC SWITCH

WHEEWHEEL

SPEEDSPEED

SENSORSSENSORS

DIAGNOSISDIAGNOSIS

ABS AMPABS LAMP

DME

MAIN

RE AY

DMEMAINRELAY

LFLF

RFRF

LRLR

RRRR

PAR BRA E

SWITCH

PARK BRAKESWITCH

X

+

BRAKE LIGHT

SWITCH

TO SZTO LSZ

DSC

CANCAN

12345

EDME

SIGNAL VOLTAGE

GROUND

POWER SUPPLYROTATION

RATE SENSOR

BRAKE

PRESSURE

SIGNAL X2

C III

MK 60

47 PIN

DSC IIIMK 60

47 PIN

ABS

ROTATION

RATE SENSOR

M o D i C

SIGNAL VOLTAGE

LATERAL

ACCELERATION SENSOR

BMWDIS

BMWDIS

UNLEADED GASOLINE ONLY

0

12

20

km/h

MPH

1/min

x1000

40

60

80

100120 140

160

180

200

220

240

1

0

2

3 4

5

6

75030 20 1512

20

40

60

80

100

120

14011

miles BRAKE ABSABSBRAKE

SERVICEENGINESOON EML

!

BRAKE

BRAKE FLUID

LEVEL SWITCH

LATERAL

ACCELERATION SENSOR

POWER

GROUND

GENERAL BRAKE

WARNING LAMP

12345

AGS

PUMP

M 60

HYDRAU IC

UNIT

MK60HYDRAULICUNIT

INLET (4X)

OUTLET (4X)

CHANGEOVER (2x)

INTAKE (2x)

POWER SUPP YPOWER SUPPLY

POWER SUPP YPOWER SUPPLY

WHEEL SPEED SENSOR REFERENCE VOLTAGE X 4

MK IIIRIGHT REAR

LEFT REAR

PROCESSED WHEEL SPEEDDSC LAMP

!

STEERING

ANGLE SENSOR

BRAKE

PRESSURE

SENSORS

BRAKE

PRESSURE

SENSORS

REFERENCE

VOLTAGE

SPLICE TO KOMBI


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System Components

The Teves D SC III M K60 consists of the follow ing com ponents:

Integrated C ontrol unit/H ydraulic unit w ith C AN Interface

Tandem M aster B rake C ylinder

Brake Expansion Tank w ith Fluid Level R eed C ontact in C ap

2 B rake Pressure Sensors

Brake Light Sw itch

4 W heel Speed Sensors (active)

Rotation R ate S ensor (yaw )

Steering A ngle Sensor (LEW )

Transverse A cceleration S ensor

D SC B utton (part of SZM )

Instrum ent cluster W arning indicators

H and brake Sw itch

W iring H arness


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Control Unit/Hydraulic Unit

The M K60 control unit/hydraulic unit is located

in the engine com partm ent on the left side

under the brake m aster cylinder.

B oth the control unit and the hydraulic unit are

replaceable as separate com ponents.

The pre-charge pum p used on previous

system s is no longer required. R apid pressure

build up is possible because of the close

proxim ity of the hydraulic unit to the m aster

cylinder and im provem ents in the design of the

return pum p.

The control unit/hydraulic unit itself is 20%

sm aller and lighter than the previous M K20 EI.

All processing functions for AB S, ASC or D SC are perform ed by the com bined control

unit/hydraulic unit. The M K 60 control unit is also responsible for processing the w heel

speed signals and providing them to other control units.

The M K60 control unit for M Y 2002 incorporates the R D W function into its scope of

control, m aking a separate R D W control unit unnecessary. The operating principle

continues to be based on the analysis of w heel speed.


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MK60 Hydraulic Unit

The hydraulic unit consists of an alum inum block containing 12 solenoid valves, 2 pressure

accum ulators and the return pum p.

4 inlet solenoid valves (N /O ) 2 changeover solenoid valves (N /O )

4 outlet solenoid valves (N /C ) 2 Intake solenoid valves (N /C )

The solenoid valving ensures that norm al braking is possible in the event of a defective

control unit.

In AB S regulation the pum p returns fluid back to the m aster cylinder circuits. In ASC /D SC

regulation w ith brake intervention, the pum p is responsible for building up the brake

pressure required for the front and rear hydraulic circuits.

Note:N/O= Normally OpenN/C= Normally Closed

FRONT AXLE BRAKE CIRCUITSREAR AXLE BRAKE CIRCUITS


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CANInterfaceThe M K 60 is connected to the C AN bus for com m unication w ith the A G S, D M E control

m odule, Steering Angle Sensor and the Instrum ent C luster.

The C AN bus allow s all of the connected control m odules to send and receive inform ationand com m ands.

C om m unication w ith the M K 60 includes:

DME - The D M E sends current engine torque. M K60 com m ands the DM E to reduce(ASC /D SC ) or raise (M SR ) engine torque.

AGS - The M K60 com m ands the A G S to suppress shifts during regulation.

LEW - The M K60 receives steering angle inform ation.

KOMBI - The M K60 com m ands the instrum ent cluster to activate or deactivate thew arning lam ps.

All four w heels speed signals are sent over the C AN bus for use by other m odules.

1 2 3 4 5

MS 43.0GS 20

SPLICE CONNECTIONSFOR TWISTED PAIR CAN

CAN BUS

MK 60

INSTRUMENTCLUSTER

UNLEADEDGASOLINE ONLY

0

12

20

km/h

MPH

1/minx1000

40

60

80

100120140

160

180

200

220

240

1

0

23 4

5

6

750

3020

1512

20

40

6080

100

120

14011

Mmiles

LEW


30/56


Tandem Master Brake Cylinder

The M K60 system uses a tandem m aster brake

cylinder fitted w ith central valves as in other D SC

m aster cylinders. The central valves allow fluidto be draw n through the m aster cylinder during

ASC and D SC regulation. The hydraulic circuit is

divided front/rear.

An inlet for pre-charge pressure is no longer

used since the charge pum p has been

elim inated from the M K60.

B oth brake pressure sensors are m ounted on

the m aster cylinder.

Expansion Tank and Brake Fluid Level Switch

The brake fluid expansion tank

has internal baffles that reduce

foam ing during return pum p

operation.

The expansion tank includes a

pick-up tube for clutch m aster

cylinder fluid supply.

The brake fluid level sw itch is

incorporated into the cap. The

sw itch is a reed contact sw itch.

If the brake fluid is at a sufficient

level, the sw itch is closed and

sw itched to ground.

If the fluid level drops below a specified level , the reed contacts open and the M K 60

responds by sw itching off the ASC /D SC functions.

N orm al braking and AB S operation is unaffected.


31/56


Brake Pressure Sensors

Tw o brake pressure sensors are m ounted on the m aster cylinder below the outlet ports for

the front and rear brake circuits. The sensors are provided a 5V reference voltage by the

M K 60 control unit.

The sensor provides the control unit w ith an analog signal proportional to brake pressure.

Voltage increases w ith increasing brake pressure.

Plausibility with BLSThe signal input from the brake

light sw itch is com pared w ith the

pressure sensor values.

The pressure sensors m ust not

detect m ore that 5 bar w hen the

B LS is not actuated.

B oth signals are used to form a

redundant B LS input w hich is

constantly m onitored.

Note: Refer to the Workshop Hints for instructions on initializing the brake pressure sensors.

Brake Light Switch (BLS)

The brake sw itch is an input to the M K 60 to inform it that the brakes are being applied. If

the signal is received during an ASC regulation then brake regulation is interrupted.


32/56


Wheel Speed Sensors (active)

W ith the introduction of the Teves D SC III M K60, active w heel speed sensors that operate

on the principle of m agnetoresistive effect are used for the first tim e on B M W vehicles.

The sensor elem ent and evaluation m odule are tw o separate com ponents w ithin the

sensor housing.

1. Metal pulse wheel 6. Sensor wiring with weather boot2. Magnet 7. Ground contact ring3. Sensor element 8. Fastening element4. Evaluation module 9. Sensor housing5. Support for sensor element 10. Pick-up surface

Principle of operation of the magnetoresistive sensorThe active sensing of the m agnetoresistive sensor is particularly suitable for advanced

stability control applications in w hich sensing at zero or near zero speed is required.

A perm anent m agnet in the sensor produces a m agnetic field w ith the m agnetic field streamat a right angle to the sensing elem ent.

The sensor elem ent is a ferrom agnetic alloy that changes its resistance based on the

influence of m agnetic fields.

1

6

4

10

3

2

5

9

7

8


33/56


As the high portion of the pulse w heel approaches the sensing elem ent, a deflection of the

m agnetic field stream is created. This causes the resistance to change in the thin film

ferrom agnetic layer of the sensor elem ent.

The sensor elem ent is affected by the direction of the m agnetic field, not the field strength.

The field strength is not im portant as long as it is above a certain level. This allow s the

sensor to tolerate variations in the field strength caused by age, tem perature or

m echanical tolerances.

The resistance change in the sensor elem ent affects the voltage that is supplied by theevaluation circuit. The sm all am ount of voltage provided to the sensor elem ent is m onitored

and the voltage changes (1 to 100m V) are converted into current pulses by the evaluation

m odule.

Signal H igh-14mA

Signal Low -7mA

The sensor evaluation circuit is supplied 12V by the M K 60 control unit. O utput voltage from

the sensor is approxim ately 10V. The control unit counts the high and low current pulses

to determ ine the w heel speed signal.

Front sensors are three w ire because they have a separate ground w ire.

R ear sensors are tw o w ire and use the sensor case as a ground point.

3

5

2

4

1

1. Metal pulse wheel

2. Magnet3. Sensor element4. Evaluation circuit5. Magnetic field


34/56


D ifferent sensors are used on the left and right side

front axle of the vehicle. The difference com es in the

length of the harness.

The connectors are blue to distinguish them apartfrom the grey connectors used for sensors on the

M K20 EI.

The D SC III M K60 uses the sam e m etal pulse

w heels used w ith the M K20 inductive sensors.

Front axle E46/Z3

Rear axle Z3 Rear axle E46, short

There are tw o types of sensors used in the rear axle of the E46:

The short sensor is used on the 325i (any transm ission) and 330i autom atic.

The long sensor is used on the 330i m anual transm ission version.

The Z3 uses the sam e sensors for the rear axle, left or right.


35/56


Rotation Rate Sensor

The R otation R ate Sensor is m ounted on a m etal bracket under the drivers seat. The

sensor provides inform ation to the M K60 concerning the vehicles speed around its m ain

axis (yaw ).

The sensor has a three pin connector w ith the follow ing connections:

5V reference

Signal

G round

The sensor receives a reference voltage of 5V from the M K60 control unit and provides a

signal output of approxim ately 0.25 to 4.65V depending on the am ount and direction of

yaw . If the sensor is defective a constant voltage w ill be sent to the M K60.

The sensor elem ent is a m icro-m echanical double quartz tuning fork. A frequency of 11

H ertz is applied to one side of the fork and as the vehicle turns on its axis, vibrations are

induced on the other end.

The sensor analyzes the signal produced by the fork and produces an analog voltage

signal that is proportional to the am ount of yaw .

The rotation (yaw ) rate is com pared to the signal from the Steering Angle Sensor and the

Transverse Acceleration S ensor. If physical lim its are beginning to be exceeded, the M K60

D SC w ill begin regulation by engine and brake intervention to attem pt to stabilize the

vehicle. This is referred to as a G M R regulation.

The M K60 D SC III for M .Y. 2002 incorporates a com bined R otation rate and Transverse

Acceleration S ensor. The Sensor is connected to the M K60 control unit by the C AN bus.

The Z3 version w ill retain separate sensors until the E36/7 is replaced by the E46/6.

Rotation RateSensor

MK60 DSC III


36/56


Steering Angle Sensor (LEW)

The Steering A ngle Sensor is m ounted tow ards the low er end of the steering colum n,

above the flexible coupling. The LEW consists of a potentiom eter and a built in

m icroprocessor. The potentiom eter has tw o pickups offset at 900 to one another. The raw

potentiom eter signal is processed and converted into a digital signal that is transm itted overthe C AN bus to the M K 60 D SC III control unit.

The sensor requires initialization in order to create a zero point default. O nce initialized the

LEW sends an ID num ber to the D SC control unit. The ID provides confirm ation that the

LEW is properly initialized.

The total steering w heel angle is determ ined by com bining the C AN telegram signal, the

stored zero point default and the actual num ber of turns to the w heel. In order to prevent

the LEW from loosing count, KL 30 is provided to the sensor and it continues to record

even after the ignition has been sw itched off.

The M K60 D SC III calculates the drivers desired rate of turn from the steering angle signal.

Pin 1. KL 30

Pin 2. KL 87

Pin 3. CAN high

Pin 4. CAN low

Pin 5. KL 31

Pin 6. TXD

Note: Refer to the Workshop Hints for instructions on coding and initializing the sensor.

POTENTIOMETERHOUSING

CAN BUS MICROPROCESSOR

CAN BUS CONNECTOR(5 WIRES)

High signal

3600 2700 1800 900 00 900 1800 2700 3600

6 PIN CONNECTOR

Potentio

meter

1

Potentio

meter

2


37/56


Transverse (Lateral) Acceleration Sensor

The Transverse Acceleration Sensor is

m ounted in the left Apillar behind the drivers

foot rest. The sensor provides the M K 60 D SCcontrol unit w ith a signal that corresponds to

the degree of transverse acceleration (G forces)

acting on the vehicle.

The sensor is a capacitive sensor w ith tw o

plates. O ne plate is rigidly m ounted, the other

plate is m ounted on a spring. U nder the effect

of transverse forces acting on the sensor the

distance betw een the plates changes.

This change of distance betw een the plates affects the capacitance of the sensor. The

evaluation circuitry converts the signal into an analog voltage that is transm itted to the

control unit.

The output signal of the sensor is betw een the range of 0.5 to 4.5 Volts. This corresponds

to -1.5 to 3.5g respectively. W hen the vehicle is stationary the output is 1.8V.

The transverse acceleration signal is used in the M K 60 D SC III control unit along w ith the

rotation rate and steering angle signal to determ ine if D SC regulation is required to m aintain

the vehicles stability.

Note: Refer to Workshop Hints for instructions on initializing sensor.


38/56


DSC Button

The D SC button is located on the SZM , how ever the SZM provides no processing, it is

sim ply a housing for the button w hich is hardw ired to the M K60 control unit.

The D SC B utton features tw o functions that can be set by varying the tim e the button is

held dow n for:

Pressing the button again returns the system to norm al status. It is not possible to godirectly from one function to the next w ithout first returning to norm al status.

Button activation Function Display

Short press Only the yaw control of the DSC is deactivated. DSC light illuminated

2.5s control functions are deactivated. brake warning light

(yellow ABL) illuminated.

Used for service and use on dynamometers.

DSC


39/56


Instrument Cluster Warning Indicators

Three w arning indicator lam ps are arranged in the instrum ent cluster:

D SC lam p: Indicates fault in D SC or system disabled by the sw itch.

AB S lam p: Indicates a fault in the AB S system .

AB LBR AKElam p: This lam p is a general brake w arning and illum inates tw o different

colors.

R ed indicates low brake fluid or hand brake engaged.

Yellow indicates D SC /AB S fault or system disabled by the sw itch.

The D SC and yellow AB L lam p are controlled by the M K60 D SC III control unit via the C AN

bus. The AB S lam p is controlled directly by the M K60 via hardw ire.

Hand brake Switch

The hand brake sw itch is an input to the M K 60 D SC to cancel M SR regulation.

0

12

20

km/h

MPH

1/minx1000

40

60

80

100120140

160

180

200

220

240

1

0

2

3 4

5

6

75030201512

20

40

6080

100

120

14011

MmilesSERVICEENGINESOON EML

BRAKE ABS


40/56


Principle of Operation

The scope of control for the M K60 D SC III is com prised of three system s:

AB S ASC +T

D SC

B ased on signals com ing from the various sensors, the M K60 D SC III w ill determ ine w hich

system is best suited to m aintain control of the vehicle.

In addition to the three basic system s, there are several sub-functions w hich are activated

during very specific circum stances. The sub-functions are:

C B C

EB V

M SR

AD B

D B C

M B C

System: Anti-Lock Braking System (ABS)

The A B S system can prevent w heel lock w hen braking by com paring the four active w heel

speed sensors to the average vehicle speed. If a w heel is locking during braking or has

dropped below a speed threshold program m ed in the control unit AB S braking w ill begin.

AB S braking is possible w hen vehicle speeds are above 12 kph (7m ph).

AB S regulation has three phases:

Pressure B uild

Pressure H old

Pressure R elease

ABS ASC

DSC

ADB

MSR

CBC

EBV

DBCMBC


41/56

Pressure B uild already occurs during norm al braking, so w hen AB S first intervenes it w ill

start holding pressure by energizing the Inlet Valve. For exam ple, if the right rear w heel is

locking up, both Inlet Valves w ill be energized, regulating both w heels together. This logic

is know n as Select Low . Front w heels can be regulated individually as needed to prevent

lockup.

Energizing the Inlet Valve closes the brake fluid passage to the calipers and traps the fluid

at the current pressure, thus not allow ing the brake pressure to rise any further.

If the w heel speed does not increase the P ressure R elease phase begins.

Pressure R elease occurs w hen the control unit energizes the O utlet Valve w hile continuing

to hold the Inlet Valve closed. The trapped brake fluid is released out of the calipers,

reducing braking pressure.

At the sam e tim e, the pum p is sw itched on w hich draw s in the released brake fluid and

pum ps it back into the pressure-build circuit restoring the volum e of brake fluid again in

front of the Inlet valve.

D epending on conditions the AB S system m ay cycle betw een these three phases from 3

to 12 tim es a second to prevent w heel lock.

41Teves D SC III M K 60

FRONT AXLE BRAKE CIRCUITSUITS


42/56


ABS Sub-functions

Corner Brake Control (CBC)C B C can occur if the vehicle is cornering and AB S regulation is not taking place.

If the control unit detects transverse acceleration in excess of 0.6g and the brakes are

applied, C B C prevents a build up in brake pressure to the inside rear w heel. This prevents

the vehicle from entering into an unstable situation that can lead to O versteer.

The M K60 accom plishes this by closing the Inlet Valve, thus not allow ing brake pressure to

increase at the brake caliper.

The difference in braking force betw een the tw o rear w heels creates a yaw force that

opposes the oversteer and allow s the vehicle to handle neutrally.

Weight of the

vehicle

Brake PressureHeld

Brake pressureallowed to increase


43/56


Electronic Brake Force Distribution (EBV)

EB V w ill adjust brake pressure to the rear axle based on the rate of slow -dow n of the rear

w heels, ensuring even brake force betw een the front and the rear of the vehicle.

The control unit m onitors the w heel speed w hen the brakes are applied and com pares the

deceleration of the front and rear axle to determ ine required regulation.

If the vehicle is m oderately to fully loaded, the rear axle w ill take longer to slow dow n, rear

w heel brakes can then be applied at a higher pressure .

If a vehicle w as lightly loaded, a sim ilar brake pressure w ould be too great and result in an

unstable situation.

If EB V control intervention is required, the control unit cycles the inlet valve on the rear brake

calipers to prevent further build-up.

B enefits of EB V are:

Enhanced braking due to even distribution of brake force.

Rear w heel brake size can be increased.

Front and rear brakes w ear at a sim ilar rate.


44/56


Automatic Stability Control (ASC+T)

B ased on input from the w heel speed sensors, the M K60 control unit determ ines if the

vehicle is loosing traction due to excessive longitudinal (straight line) w heel slip. An ASC

regulating sequence is initiated if the w heel slip exceeds the control units stored allow ablevalues.

A critical slip ratio of up to 5% betw een the w heels w ill cause the traction control regulation

to begin. This slip ratio is established w hen the system detects a w heel spin difference of

2M PH or greater.

ASC regulation is cancelled at any tim e if the brake pedal is applied.


45/56


The M K60 can control longitudinal w heel slip by tw o m eans:

Engine Intervention

Brake Intervention (ADB, drive wheels only)

Engine InterventionEngine torque m ay be reduced by:

Reducing the throttle opening angle

Retarding the ignition

C anceling individual cylinders by fuel injection cutout.

The M K60 D SC III control unit determ ines the am ount of torque reduction that is

necessary and sends the request for regulation to the D M E via the C AN bus.

Brake Intervention (ADB)B rake intervention is applied to the individual drive w heel w hich is loosing traction by

regulating the brake calipers in three phases:

Pressure B uild

Pressure H old

Pressure R elease

W hen brake intervention is necessary, the front w heels m ust be isolated from the Pressure

B uild sequence in the hydraulic unit.

H ere is an exam ple of an ASC brake intervention at the left rear w heel:

The C hangeover Valve for the rear brake circuit, the right rear and both front Inlet Valves

are energized and closed.

The rear brake circuit Intake Valve is energized and opened.

The R eturn/Pressure pum p is activated and draw s brake fluid through the open Intake

Valve from the M aster C ylinder (via the Central Valve) and delivers the pressurized fluid to

the open Inlet Valve braking the left rear w heel.

Pressure H old and Pressure R elease are done by cycling the Inlet and O utlet Valves

sim ilar to the AB S sequence described previously.

The control unit decides w hich regulation m ethod should take place based on input

criteria and chooses from tw o regulating principles:

Select-H igh

Select-Low


46/56


Select-High RegulationIn a S elect-H igh regulation, the M K 60 control unit selects the drive w heel w ith the highest

am ount of traction and uses it as the basis for evaluation.

Engine torque is reduced slightly by request to the D M E. The w heel w ith the least am ount of traction is braked. This allow s a torque transfer to

the w heel w ith the higher am ount of traction (similar to a locking differential).

Select-H igh is used if the vehicle speed is below 40 kph (25 m ph).

Select-Low RegulationIn a Select-Low regulation, the M K 60 control unit selects the drive w heel w ith the low est

am ount of traction and uses it as the basis for evaluation.

Engine torque is reduced until the w heel slip is no longer present.

Brake regulation is notcarried out.

Select-Low is used if the vehicle speed is above 40 kph (25 m ph).

ASC Sub-functions

Engine Drag Torque Reduction (MSR)If the vehicle is driven in low gear w hen coasting dow n hill, or if there is a sudden shift to a

low er gear, the w heels m ay be slow ed by the engines braking effect too rapidly. This could

result in an unstable situation.

If the front w heels are turning faster than the rear w heels, the M K 60 control unit signals the

D M E via the C AN bus to raise the engine torque. D M E cancels fuel cut-off and allow s the

engine speed to increase, this allow s the drive w heels to accelerate to m atch the speed of

the non-driven w heels.

M SR regulation is cancelled if the brake pedal or hand brake are applied.


47/56


Modified ADB function (2-wheel drive vehicles equipped with MK60)The AD B is an autom atic differential lock that im proves traction. The slipping w heel is

braked by pressure built up in the hydraulic unit. The drive torque can be transferred to the

w heel w ith the greater traction, w hich can transm it drive pow er to the road. This function

takes the place of a lim ited slip differential.

The M K60 D SC IIIsystem incorporates tw o m ethods of AD B based on the D SC sw itch

input to the control unit. W ith the system onthe AD B w orks w ith engine intervention at

a threshold of below 40kph(24 m ph).

Tapping the D SC sw itch (


48/56


Dynamic Stability Control (DSC)

W ith the introduction of D SC system s, lateral dynam ics w ere taken into account for the first

tim e. The M K 60 D SC III system w ill initiate a D SC regulation sequence if the control unit

detects a difference betw een the drivers desired turning angle and the actual rotation angleof the vehicle. The control unit determ ines vehicle stability based on:

Steering w heel angle

W heel speed

Transverse acceleration forces

Rotation angle and speed (yaw )

O nce the control unit determ ines that the vehicle is in an unstable situation, it also

identifies w hether it is oversteering or understeering. This distinction is im portant because

it determ ines w hich control strategy should be used to help stabilize the vehicle.

D SC regulation consist of :

Engine intervention

Engine and brake intervention (any wheel)

Brake intervention

Understeer Detected: Engine Torque Reduction Brake applied to inside

rear wheel.

Oversteer Detected: Engine Torque Reduction. Brake applied to outside

wheels.

Determination of Oversteer or Understeerand Decide on Corrective Action

Establish the DifferenceBetween Actual and Desired

LateralAcceleration

Value

Rotation (yaw)AngleValue

Comparison ofSteering Angle

and Wheel

Determination ofDrivers DesiredTurning Rate

Determination ofVehicle ActualTurning Rate


49/56


UndersteerU ndersteer occurs w hen the driver w ishes to turn a corner but despite the front w heels

being turned in the direction of the curve the vehicle continues its track forw ard. This

occurs w hen the front w heels no longer have sufficient lateral locating force (traction).

The M K60 D SC III can identify the situation and initiate a corrective action based on engine

torque reduction follow ed by a controlled brake intervention sequence if needed.

Engine torque reduction is carried out by the D M E from a request by the D SC via the C AN

bus. The D M E telegram s the torque reduction confirm ation back to the D SC .

B rake intervention is carried out by the M K60 hydraulic unit if the driver is not actively

braking. An exam ple of a brake intervention at the inside rear w heel is as follow s:

All Inlet Valves are closed except for the right rear inlet.

Intake Valve for rear circuit is opened.

Both C hangeover Valves are closed.

Return pum p operated.

UNDERSTEER CORRECTION1. VEHIC LE APPR O AC H ES TUR N :

- D river steers into turn

- B rakes are applied

2. D SC III detects an U ndersteer

C ondition based on vehicle speed, w heel speed differential,

turning angle, lateral acceleration forcesand yaw angle.

- Engine torque reduction active

- Inside rear w heel brake regulate

WITH DSC III

WITHOUTDSC III

1

2

3

- regulated brake slow sw heel dow n (and helps to

reduce vehicle speed). W heel onoutside of curve speeds up due to pow er transfer thru differential.

Vehicle pivots in favor of curve. C om bined, this forces the vehicle into the turn.

3. VEH IC LE

C O M ES O U T

O F TUR N SUCCES-

FU LLY


50/56


Just as an ASC regulation, D SC brake intervention carries out:

Pressure B uild

Pressure H old

Pressure release



51/56


OversteerO versteer occurs w hen the driver w ishes to turn a corner and the tail of the vehicle slides

outw ard leading the turn. This is caused by the rear tires loosing traction and not being able

to hold against the centrifugal force acting upon the vehicle.

The M K60 D SC III can identify the situation and initiate a corrective action based on engine

torque reduction follow ed by a controlled brake intervention sequence if needed.

Engine torque reduction is carried out by the D M E from a request by the D SC via the C AN

bus. The D M E sends the torque reduction confirm ation back to the D SC .

OVERSTEER CORRECTION1. VEH IC LE AP PR O AC ES TUR N AT H IG H RATE O F SPEED : - D river steers into turn and applies brakes to slow dow n.

2B . D river tries to com pensate by oversteering w hich

dim inishes lateral locating force even further.

Sim ultaneously, rear of car starts to slide out.

WITH DSC III WITHOUTDSC III

1

2

3

3. VEH IC LE C O M ES O UT OF TURN

SUCCESFULLY

2C . D SC III determ ines an O VER STEER condition.

Engine torque is reduced via C AN B us signalling. O utside rear w heel is m om entarily regulated to

counteract severe yaw angle (also helps to reduce

drive torque further.)

2A. Lateral locating forces are dim inished on rear w heels

due to high speed and centrifugal force of

vehicle in turn.

2D . The torque reduction and rear brake regulation

should stabilize the vehicle at this point. If not

the left front w heel has a high degree of lateral

locating force and is m om entarily regulated.

This action deliberately causes the w heel to sheda calculated degree of it's locating force. This

counteracts oversteer yaw at this w heel and alsoaids in slow ing the vehicle dow n to correct it.


52/56


B rake intervention is carried out by the M K60 hydraulic unit if the driver is not actively

braking. An exam ple of a brake intervention at the left outside w heel is as follow s:

All Inlet Valves are closed except for the left rear inlet.

Intake Valve for rear circuit is opened. Both C hangeover Valves are closed.

Return pum p operated.



53/56


DSC Sub-functions

Dynamic Brake System (DBS)D B S is designed to assist the driver in em ergency braking situations by autom atically

increasing pressure to the vehicles brake system . This allow s the vehicle to stop in theshortest distance possible. D B S w as first available in 1999 B osch D SC III 5.7 system s. It

is available on a C ontinental Teves system for the first tim e w ith M K60 D SC III.

The D B S system contains tw o functions: D ynam ic B rake C ontrol and M axim um B rake

C ontrol. D B S functions are program m ed into the M K60 control unit and require no addi-

tional hardw are over conventional D SC .

Dynamic Brake Control (DBC)The D B C function is designed to provide an increase in braking pressure up to the AB S

threshold during rapid (em ergency) braking situations. The M K60 control unit m onitors the

inputs from the brake light sw itch and the brake pressure sensors on the m aster cylinder.

The triggering criteria for activation of D B C is, how rapidly is the brake pressure increasing

w ith an application of the brake pedal. The triggering conditions are:

Brake light sw itch on.

Brake pressure in the m aster cylinder above threshold.

Brake pressure build-up speed above threshold.

Vehicle road speed above 3m ph (5km h).

Pressure sensor self test com pleted and sensors not faulted.

Vehicle traveling forw ard.

N ot all of the w heels in AB S regulation range.

If the threshold for D B C triggering is achieved, the M K 60 control unit w ill activate a

pressure build-up intervention by activating the return pum p. The pressure at all w heels is

increased up to the A B S regulation point. This ensures that the m axim um brake force is

applied to the vehicle.

D uring D B C the rear axle is controlled w ith Select-Low logic and the front w heels are

regulated individually. D B C w ill continue until:

The driver releases the brake pedal.

Brake pressure falls below threshold. Vehicle road speed below 3m ph.

D B C w ill also be sw itched off if a fault occurs in w ith any of the necessary input sensors.

A fault in D B C w ill illum inate the BR AKE(AB L) lam p yellow to w arn the driver, depending

on the type of failure the D SC lam p m ay be illum inated as w ell.


54/56


Maximum Brake Control (MBC)The M B C function is designed to support driver initiated braking by building up pressure in

the rear brake circuit w hen the front w heels are already in AB S regulation.

The additional braking pressure is applied to bring the rear w heels up to the A B Sregulation point shortening the stopping distance. The M B C function is triggered w hen the

brakes are applied m ore slow ly than the threshold needed for a D B C regulation. The trig-

gering conditions are:

Both front w heels in A B S regulation.

Vehicle road speed above 3m ph (5km h).

D B C and pressure sensor initialization test successful.

Vehicle traveling forw ard.

Rear w heels not in A B S regulation.

If the threshold for M B C triggering is achieved, the M K60 control unit w ill activate a

pressure build-up intervention by activating the return pum p. The pressure at the rear

w heels is increased up to the AB S regulation point. This ensures that the m axim um brake

force is applied to the vehicle.

The M B C function w ill be sw itched off if:

Front w heels drop out of AB S regulation.

The driver releases the brake pedal.

Brake pressure falls below threshold.

Vehicle road speed below 3m ph.

M B C w ill also be sw itched off if a fault occurs in w ith any of the necessary input sensors.

A fault in M B C w ill illum inate the BR AKE(AB L) lam p yellow to w arn the driver, depending

on the type of failure the D SC lam p m ay be illum inated as w ell.


55/56


Workshop Hints

Diagnosis

D iagnosis of the M K60 D SC IIIis carried out using the D ISplus or M oD iC

Control Unit Functions:Expert m ode diagnosis available

at any tim e during troubleshoot-

ing. To enter: press the C ontrol

U nit Functions button at the

right low er corner of the screen.

The contents are:

Identification Delete Fault Memory Read Fault Memory

Component Activation Status queries (requests)

Service Functions:Provides access to specialized test m odules

used as post repair procedures. To enter:

Function Selection

Service Functions

C hassis

D ynam ic S tability C ontrol M K60

The contents are:

Connection Speed Sensor: A test toverify the proper w iring to the w heel

speed sensors

Connection Brake Lines: A test toverify the proper brake pipe connections

to the hydraulic unit.

Adjustment Functions: Test m odulesto initialize certain com ponents after

repair w ork is perform ed

Steering Angle S ensor

Lateral Acceleration Sensor

Pressure S ensors

Test Modules: Faults w ith the M K60 system can be diagnosed using fault or sym ptom driven testm odules. To begin diagnosis:

Perform the Quick Test. Select Vehicle Symptom from the Symptom Selection page. Select Test Module from Test Plan page. Press the Test Schedule Button.Test M odules are configured in the E46 diagnosis concept.


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CodingC oding m ust be perform ed after replacem ent

of the M K60 control m odule or the steering

angle sensor. ZC S coding is found in the

C oding and Program m ing selection from thestart screen or w hen pressing the C hange

button. Follow on-screen instructions for

initialization of com ponents after com pleting

the coding process.

Adjustment FunctionsAdjustm ent (initialization) is required w hen:

Replacing the M K60 C ontrol U nit.

Replacing/R e-coding the Steering Angle S ensor.

Replacing one or both B rake P ressure Sensors.

Replacing Lateral Acceleration S ensor.

Steering Angle SensorThe steering angle sensor requires an offset adjustm ent after the sensor has been replaced,

coded or after repairs to the steering or suspension system . The offset adjustm ent inform s

the steering angle sensor processor of the straight ahead position of the front w heels.

The adjustm ent is perform ed by com pleting the Test M odule found in Service Functions.

O nce the adjustm ent is com plete the sensor sends an identification num ber over the C AN

bus to the D SC control unit. The ID provides confirm ation that the steering angle sensor is

coded and has successfully com pleted the adjustm ent procedure.

Special ToolsSpecial Tools available for the Teves D SC III M K60 consist of:

47 PinV-Cable 34 5 250 60 Pin Break-Out-Box

BMW Coding/programming SELECTION

1 CAR MEMORY

2 KEYMEMORY

3 ZCS CODING

4 PROGRAMMING

5 ALIGNMENT EWS-DME

6 ALIGNMENT EWS-DDE

Print Change End Services

Note

13 P1 Traction and Stability Control Internet

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