abs brakes-teves mkii

1

Mark II Anti-Lock Brakes

Contents

Overview 2 – 5

System Description 6 – 7

System Operation 8 – 15

Components 16 – 23

Diagnostic Trouble Codes (Blink Codes) 24

The DTC Summary for this section follows at the end of the section.

2


Overview

The Teves MK II brake system combines normal system operation, hydraulic power boost andanti-lock braking. The system uses an independent electrically-driven motor / pump unit to pro-vide both boost pressure and brake application pressure. A common operating fluid, DOT 4BRAKE FLUID, is used for both power boost and brake application.

In this system, three hydraulic circuits are used — one to each front wheel and one to the rearwheels. Depending on the mode of operation, the circuits operate differently:

Normal Operation

The two front hydraulic circuits operate conventionally via the master cylinder, assisted by thehydraulic booster. The rear hydraulic circuit is operated continuously by the controlled pressurein the booster via the pressure reducing valve. Simply stated, during normal operation, the fronthydraulic circuits are “static” and the rear circuit “dynamic.”

Anti-lock Operation

When anti-lock control is required, the front hydraulic circuits also become “dynamic” as boostpressure replaces master cylinder pressure via the main valve.

The four wheel speed sensors input to the ABS control module (ABS CM), which processes theinformation and modulates the three sets of solenoid valves in the valve block to control thepressure in the three circuits and prevent wheel lock. Because both rear wheels share a com-mon circuit, a tendency for one wheel to lock will result in control of both wheels according tothe need of the “locking” wheel.

The state of the anti-lock braking system is continuously monitored by the ABS CM. If a systemfault is detected, the CM flags a diagnostic trouble code (DTC) corresponding to the fault , acti-vates the ANTI LOCK MIL, stores the DTC in its nonvolatile memory and signals the instrumentpack vehicle condition monitor (VCM). For most faults the CM will also switch the system OFFuntil the fault is corrected.

Full boosted braking to all wheels is maintained if the control module switches off the ABS sys-tem. If a failure of the hydraulic boost portion of the system occurs, the brake system willfunction on the front wheels only, without boost pressure.

MK II ABS ENGINE COMPARTMENT COMPONENTS: SEDAN RANGE 1993 – 1994 MY

HYDRAULICACTUATION UNIT

T500/2.01

MOTOR / PUMPUNIT

3


Fault Diagnostics

In addition to JDS and PDU diagnostics accessed through the dedicated ABS diagnostic connec-tor, located near the CM, the TEVES MK II anti-lock braking system incorporates a facility thatallows the numeric DTCs to be displayed as coded blinks on the ABS MIL.

Refer to page 24 for instructions for activating the “blink code” display.

MK II ABS SYSTEM: SEDAN RANGE 1990 – 1992 MY

MOTOR / PUMPUNIT


FRONT WHEEL SPEED SENSORS

PRESSURE REDUCING VALVE

ABS CONTROLMODULE

T500/2.02

MK II ABS SYSTEM: XJS RANGE UP TO 1995 MY VIN 198335 (INBOARD REAR BRAKES SHOWN)

MAINVALVE

ACCUMULATOR

MOTOR / PUMPUNIT

COMBINED PRESSURESWITCH

FRONT WHEELSPEED SENSORS

SOLENOID VALVEBLOCK

PRESSUREREDUCING VALVE

ABS CONTROLMODULE

REAR WHEELSPEED SENSORS

HYDRAULICACTUATOR

RESERVOIR

T500/2.03

4


Overview (continued)

Sedan Range: 1990 – 1992 MY

In the Sedan Range from model years 1990 – 92, the motor / pump unit, reservoir and hydraulicactuation unit are integrated on the brake pedal and accelerator housing. The motor / pump unitcontains the hydraulic pump, motor, accumulator and combined pressure switch. The hydraulicactuator incorporates many components including the solenoid valve block.

NOTES

ABS MOTOR / PUMP UNIT, RESERVOIR AND HYDRAULIC ACTUATION UNIT: SEDAN RANGE 1990 – 1992 MY

ACCUMULATORRESERVOIR


SOLENOID VALVEBLOCK

MOTOR / PUMPUNIT

COMBINEDPRESSURE SWITCH

T500/2.04

5


Sedan Range: 1993 – 1994 and XJS Range: 1989 – 1995 MY

In all XJS Range models and 1993 – 94 Sedan Range models, the motor / pump unit is locatedseparately on the right side of the firewall. The reservoir and the hydraulic actuation unit are inte-grated on the brake pedal and accelerator housing. The motor / pump unit contains the hydraulicpump, motor, accumulator and combined pressure switch. The hydraulic actuator incorporatesmany components including the solenoid valve block.

NOTES

ACCUMULATOR

RESERVOIR


SOLENOID VALVEBLOCK

MOTOR / PUMPUNIT

COMBINEDPRESSURE SWITCH

ABS MOTOR / PUMP UNIT, RESERVOIR AND HYDRAULIC ACTUATION UNIT: SEDAN RANGE 1993 – 1994 MYAND XJS RANGE UP TO 1995 MY VIN 198335

T500/2.05

6


System Description

Hydraulic Actuation Unit

The hydraulic actuation unit contains the reservoir and the components used for pressure appli-cation, boost application and anti-lock valving.

Actuating piston

The actuating piston transmits the motion from the brake pedal to the control valve and the boost piston.

Control valve

The control valve opens and closes the high pressure line from the accumulator to the actuatorhydraulic booster.

Hydraulic booster

The boost piston is independent from the actuating piston and applies boost pressure on themaster cylinder piston. Boost pressure is used to directly operate the rear brakes.

Master cylinder

The master cylinder operates the front brakes only.

Main valve

The solenoid-activated main valve is opened under anti-lock conditions to apply boost pressuredirectly to the master cylinder and the front brake circuits.

Central valve

The central valve opens under anti-lock conditions to allow boost pressure to be applied directlyto the front brakes.

Positioning sleeve

The positioning sleeve is used during anti-lock operation to minimize brake pedal pulsation.

Solenoid valves

The six solenoid valves direct hydraulic pressure and hydraulic return in the three brake circuitsduring anti-lock conditions. During normal operation, the valves are at rest, allowing conventionalapplication.

Motor / Pump Unit

The motor / pump unit supplies the system-operating hydraulic pressure.

Pump

The pump is driven by an electric motor and is switched on and off to maintain a range of oper-ating pressure.

Accumulator

The accumulator stores the pump pressure and provides reserve for normal, anti-lock and pumpfailure operations. A check valve prevents pressure loss.

Pressure control valve

The pressure control valve limits the maximum system pressure to 210 bar (3046 psi).

Combined pressure switch

Two sets of contacts in the pressure-operated switch signal the ABS control module for activa-tion of warnings and anti-lock shutdown. The other contacts switch the pump on and off. (Thebrake warning switch contacts close at 105 bar [1255 psi] turning on the warning light. The pumpswitches on at approximately 140 bar [2030 psi] and off at approximately 180 bar [2610 psi].)

Pressure Reducing Valve

Because the rear brakes operate directly off boost pressure, a pressure-limiting device is neces-sary. The pressure reducing valve is located in the rear brake circuit and limits the pressureapplied to the rear brakes. (A differential of 6 bar [87 psi] is maintained between the front andrear circuits.)

7


TEVES MK II ABS SYSTEM DIAGRAM

T500/2.06

MO

TO

R /

PU

MP

UN

IT

PU

MP

AC

CU

MU

LA

TO

R

CH

EC

K V

ALV

E

PR

ES

SU

RE

CO

NT

RO

L V

ALV

E

CO

MB

INE

DP

RE

SS

UR

ES

WIT

CH

RE

SE

RV

OIR

MA

IN V

ALV

EP

OS

ITIO

NIN

GS

LE

EV

E

MA

ST

ER

CY

LIN

DE

R

CE

NT

RA

LV

ALV

E

MA

ST

ER

PIS

TO

NB

OO

ST

PIS

TO

N

HY

DR

AU

LIC

AC

TU

AT

OR

AC

TU

AT

ING

PIS

TO

N

CO

NT

RO

LV

ALV

E

SO

LE

NO

IDV

ALV

ES

HY

DR

AU

LIC

AC

TU

AT

ION

UN

IT

FR

ON

T B

RA

KE

SR

EA

R B

RA

KE

S

8


System Operation

Brakes Not Applied

Control valve

The control valve is open to the reservoir and closed to accumulator pressure from the motor /pump unit.

Pump

The pump is switched on or off as determined by system pressure.

Accumulator

The accumulator stores boost pressure for use as soon as brakes are applied.

Boost piston

The boost piston is retracted.

Positioning sleeve

The positioning sleeve is at rest.

Master cylinder

The master cylinder is at rest.

Main valve

The main valve is switched off.

Equalized hydraulic pressure The hydraulic pressure is equalized throughout the system (exceptin the accumulator-to-control valve line).

NOTES

9


TEVES MK II ABS SYSTEM: BRAKES NOT APPLIED

T500/2.07

PR

ES

SU

RE

S: RE

SE

RV

OIR

AC

CU

MU

LA

TO

R

BO

OS

T

MA

ST

ER

CY

LIN

DE

R

10


System Operation

Brakes Applied: Normal Operation

Control Valve

As the driver applies force to the brake pedal, the actuating piston moves forward. The levermechanism moves the control valve forward, opening the port from the accumulator and clos-ing the return port to the reservoir. Boost pressure is applied to the boost piston and the rearbrakes.

Boost Piston

The boost piston increases the pedal force acting on the master cylinder piston.

Main Valve

The main valve remains at rest, connecting the master cylinder to the reservoir.

Central Valve

As the master cylinder piston moves forward, the central valve closes and pressure is built up inthe front brake circuits.

Positioning Sleeve

The positioning sleeve moves forward with the boost piston. The displaced fluid returns to thereservoir through the main valve, which is at rest.

Pressure Reducing Valve

Boost pressure is applied to the rear brakes through the pressure reducing valve.

Solenoid Valves

All solenoid valves are at rest, allowing pressure application and preventing return to the reservoir.

Boost Pressure Control

As the boost pressure increases, it acts between the boost piston and the actuating piston,moving the actuating piston back, which moves the control valve to close the port from theaccumulator. The control valve closes the accumulator pressure port when the pedal force andboost force acting on the actuating piston equalize. The return port to the reservoir remainsclosed. The resulting pressure in the booster is proportional to the pedal force:low pedal force = low pressure, high pedal force = high pressure.

“Dynamic”, “Static” During normal operation, boost pressure is applied directly to the rearbrake circuit, thus the description “dynamic”. The front brake master cylinder is supplied withreservoir gravity pressure only, thus the description “static.”

NOTES

11


TEVES MK II ABS SYSTEM: BRAKES APPLIED – NORMAL OPERATION

T500/2.08

PR

ES

SU

RE

S:

RE

SE

RV

OIR

AC

CU

MU

LA

TO

R

BO

OS

T

MA

ST

ER

CY

LIN

DE

R

MA

IN V

ALV

EP

OS

ITIO

NIN

GS

LE

EV

E

CO

NT

RO

L V

ALV

E

CE

NT

RA

LV

ALV

E

MA

ST

ER

PIS

TO

NB

OO

ST

PIS

TO

N

AC

TU

AT

ING

PIS

TO

N

12


System Operation

Brakes Applied: Anti-Lock Operation

Main Valve

When the ABS control module senses the need for ABS control, it activates the main switch,which moves the main valve, closing the reservoir feed line and applying boost pressure to themaster cylinder circuit.

Central Valve

The central valve is held open by the pressure, allowing boost pressure to be applied directly tothe front brake circuits.

Positioning Sleeve

The positioning sleeve is gradually moved to its rest position by the boost pressure. This actionpushes back the boost piston, the actuating piston and the brake pedal, minimizing ABS pulsa-tion transmitted to the brake pedal.

Solenoid Valves

The solenoid valves are modulated by the ABS control module, as necessary, to prevent wheel lock.

“Dynamic” During ABS operation, both the front and rear brake circuits are “dynamic”, as thefront brakes are also operated directly by boost pressure.

NOTES

13


TEVES MK II ABS SYSTEM: BRAKES APPLIED – ANTI-LOCK OPERATION

T500/2.09

PR

ES

SU

RE

S: RE

SE

RV

OIR

AC

CU

MU

LA

TO

R

BO

OS

T

MA

ST

ER

CY

LIN

DE

R

MA

IN V

ALV

EP

OS

ITIO

NIN

GS

LE

EV

E

CE

NT

RA

LV

ALV

E

SO

LE

NO

IDV

ALV

ES

BO

OS

TP

IST

ON

14


System Operation (continued)

Solenoid Valve Operation

A pair of solenoid valves for one control circuit is shown. During ABS operation, the ABS con-trol module modulates the valves in three phases as necessary to prevent wheel lock. The threephases are repeated up to six times per second until wheel lock is eliminated.

Normal operation

During normal braking operation, the sole-noid valves are not controlled by the ABScontrol module and no current is applied.The inlet valve is open and the outlet valve isclosed, porting hydraulic pressure to thebrake caliper circuits.

Phase one: Pressure hold

To maintain brake pressure, the ABS controlmodule activates the inlet valve, which closesand prevents the application of additional hydrau-lic pressure. The outlet valve remains closed,preventing return to the reservoir.

NOTES

NORMAL OPERATION

HYDRAULICPRESSURE

BRAKECALIPERS

RESERVOIR

T500/2.10

PRESSURE HOLD

HYDRAULICPRESSURE

BRAKECALIPERS

RESERVOIR

T500/2.11

15


Phase two: Pressure reduce

If a wheel still has a tendency to lock withthe pressure maintained, the ABS controlmodule activates both valves, which pre-vents the application of hydraulic pressureand allows return to the reservoir, decreas-ing the pressure in the brake circuit.

Phase three: Pressure increase

As the wheel accelerates, the ABS controlmodule deactivates both valves, allowinghydraulic pressure to be applied to thebrakes.

NOTES

PRESSURE REDUCE

HYDRAULICPRESSURE

BRAKECALIPERS

RESERVOIR

PRESSURE INCREASE

HYDRAULICPRESSURE

BRAKECALIPERS

RESERVOIR

T500/2.13

T500/2.12

16


Components

ABS Control Module

The ABS control module (ABS CM) processesinformation from the wheel speed sensorsand the various switches for system opera-tion, control and warnings. The wheel speedinput signals are converted into values thatcorrespond to relative individual wheel speed.These values are used to control the solenoidvalves during ABS operation.

A vehicle speed is output to the instrumentpack for distribution to other vehicle systems.The speed signal is provided from the ABSCM on 1993 and 94 Model Year Sedan Rangevehicles. The left rear wheel speed sensorinput is used as the wheel speed source.

ABS CM diagnostic monitoring

Each time the ignition is switched ON, theABS CM conducts a self-test to determinesystem condition. The length of the test isdependent on the time required for chargingof the accumulator. The instrument pack ABSMIL is illuminated during this test. If a fault isdetected by the CM, the ABS MIL remainsactivated, the ABS system is switched off anda DTC is stored in memory.

During routine driving, the CM continuouslymonitors the system input and output signals.If a failure is detected, the ABS MIL is acti-vated. If an ABS fault is detected, ABS iscanceled; however, normal boosted brakingwill be maintained.

Refer to the DTC Summary following this sec-tion of the book.

NOTES

TEVES MK II ABS CONTROL MODULE

T500/2.14

17


Hydraulic Brake Booster

The hydraulic booster boosts brake pedal forceusing hydraulic force supplied from the sys-tem pump. The pressure in the booster is pro-portional to the pedal force. Brake hydraulicpressure to the rear wheel brakes is appliedthrough the control valve. Because the rearbrakes are always operated dynamically, thehydraulic pressure to the rear brakes will neverexceed 195 bar (maximum system pressure).

Hydraulic brake booster diagnostic monitoring

Hydraulic brake booster pressure is monitoredby the CM via the combined pressure switch.


NOTES

TEVES MK II HYDRAULIC BRAKE BOOSTER

UPPER ARTICULATEDBALLS

CONTROLVALVE

RESERVOIR

BOOSTERPISTON

LOWER ARTICULATEDBALLS

ACTUATINGPISTON

SCISSOR

T500/2.15A & B

18


Components (continued)

Motor / Pump Unit

The pump supplies hydraulic pressure for sys-tem operation. When hydraulic pressure in theaccumulator falls to the low switching point,128.5 – 149 bar (1863 – 2161 psi), the pump isswitched ON by the combined pressure switchand pressurizes the system until the accumula-tor pressure reaches the high switching point,171 – 195 bar (2480 – 2828 psi).

Hydraulic accumulator

Adequate system hydraulic pressure is maintainedby the hydraulic accumulator. The accumulator isa pressure vessel with two chambers separated bya membrane. The upper chamber is charged withnitrogen gas at an initial pressure of 84 bar (1218psi). The lower chamber fills with pressurized hy-draulic fluid and is made available for systemoperation. Accumulator pressure is maintained bya check valve located in the motor / pump unit.

NOTES

TEVES MK II MOTOR / PUMP UNIT

ACCUMULATOR


PUMP


TAPPET

CHECK VALVE

FILTERSUCTIONCHANNEL

ECCENTRICRING

CONTROLSHAFT

BALLSROTORCOUPLINGMOTORPISTONS

T500/2.16A & B

TEVES MK II HYDRAULIC ACCUMULATOR

UPPERCHAMBER

MEMBRANE

LOWERCHAMBER

T500/2.17

19


Combined pressure switch

The combined pressure switch containsthree pressure-operated switches. The two“normally open” switches close when nor-mal operating pressure is reached, switchingoff the pump and the BRAKE warning.The third “normally closed” switch opens ifthe system pressure falls too low and sig-nals the ABS control module, which lightsthe ABS MIL. XJS 1989 MY systems use acombined pressure switch with two “nor-mally closed” switches and one “normallyopen” switch.

Motor / pump unit, hydraulic accumulator and combined pressure switch diagnostic monitoring

A failure in the motor / pump unit, hydraulic accumulator or combined pressure switch will bedetected by CM monitoring of hydraulic pressure via the combined pressure switch.

Refer to the DTC Summary following this section of the book.

NOTES

TEVES MK II COMBINED PRESSURE SWITCH

PRESSURESWITCH

WARNINGSWITCH

SPRING TAPPET

T500/2.18A & B

20



Valve Block

The valve block contains three pairs of electroni-cally controlled solenoid valves. One pair ofsolenoid valves (one inlet and one outlet valve)is used for each brake circuit. If a wheel ap-proaches lockup during ABS operation, the CMcontrols the brake apply pressure in the wheel’shydraulic circuit by modulating the solenoidvalve operation.

Valve block diagnostic monitoring

The CM continuously monitors ABS systemoperation and the state of the components.If the CM detects a solenoid valve electricalor hydraulic failure, the ABS system isswitched off, the ABS MIL is activated and aDTC is stored in memory.


NOTES

TEVES MK II VALVE BLOCK

OUTLET VALVE

INLET VALVE

T500/2.19A & B

21


Master Cylinder

The master cylinder acts on the front brakesonly (static hydraulic circuit). The hydraulicpressure in the master cylinder is generatedby the force applied from the booster piston.The main valve is incorporated into the mastercylinder.

Main valve

The solenoid operated main valve is activatedby the ABS control module during ABS controlto supply the front wheel brakes and the posi-tioning sleeve with system hydraulic pressure.The hydraulic force acting on the positioningsleeve moves the sleeve to push back thebrake pedal.

Master cylinder and main valve

diagnostic monitoring

The main valve is continuously monitored bythe ABS CM. If the CM detects a main valveor hydraulic pressure failure, the ABS systemis switched off, the ABS MIL is activated anda DTC indicating the failure mode is stored.


NOTES

TEVES MK II MASTER CYLINDER

MAIN VALVE

MAINVALVE

CENTRALVALVE

PRIMARYSEAL

MASTERCYLINDER

PISTON

POSITIONINGSLEEVE

BOOSTERPISTON

T500/2.20A & B

TEVES MK II MAIN VALVE

RESERVOIRMASTER

CYLINDER

SOLENOIDVALVE

T500/2.21

22



Reservoir

XJS Range

The reservoir contains three fluid-level operated reed switches. Two “normally open” switcheslight the BRAKE FAILURE warning if the level drops too low. The third, “normally closed” switchsignals the ABS CM if the level drops below the minimum level required for full ABS operation.In this case, the ABS CM switches off the front wheel ABS and activates the ABS MIL.

Sedan Range

The reservoir contains two fluid-level operated reed switches. The “normally open” switch ac-tivates the VCM (vehicle condition monitor) BRAKE warning if the level drops too low. The“normally closed” switch signals the ABS CM if the level drops below the minimum level re-quired for full ABS operation. In this case, the ABS CM switches off the front wheel ABS andactivates the ABS MIL.

Diagnostic Connector

A diagnostic connector, located near the ABS control module, is provided for conducting systemtesting using JDS or PDU.

NOTES

23


Wheel Speed Sensors

Each wheel speed sensor is made up of a magnetic sensor and a rotating 48-tooth reluctor.When the reluctor turns, it produces electrical signals that are fed to the ABS CM as individualwheel speed information.

Wheel speed sensor diagnostic monitoring

The wheel speed sensors are continuously monitored by the CM. If the CM detects a sensorfailure, the ABS system is switched off, the ABS MIL is activated and a DTC indicating the sen-sor and failure mode is stored.

Refer to the DTC Summary following this section of the book.

MAGNETICCORE

TOOTHEDROTOR

COIL

WHEEL SPEED SENSORS

SEDAN RANGE

FRONT REAR

XJS RANGE

FRONT REAR

T500/2.22A – D, 2.23

24


Diagnostic Trouble Codes (Blink Codes)

The ABS CM continuously monitors the ABS system input and output signals. If a failure isdetected, the CM activates the ABS MIL and either switches the ABS system off or inhibits itsoperation, depending on the failure. The CM also stores a two digit code (DTC) that indicates thetype of failure. Refer to the DTC Summary following this section of the book.

DTCs are displayed by coded flashes (‘blink codes’) of the ABS MIL.

TO ACTIVATE ‘BLINK CODES’ (DTC display):– Switch the ignition OFF– At the ABS diagnostic connector located in wheel arch near the ABS CM, jump the N/K

(brown / pink) wire pin to the B (black) wire pin with a short JDS adapter.– Observe the ABS MIL and switch the ignition ON. The ‘BLINK CODE’ sequence will begin in

six seconds.– Count the flashes (MIL ‘BLINKS’). Each digit of the DTC is separated by a two second pause.

Individual DTCs are separated by a six second pause.

EXAMPLE: Stored DTCs 21 and 31 display as follows:

IGNITION ON … (6 second pause) …2 BLINKS … (2 second pause) … 1 BLINK … (6 second pause) …3 BLINKS … (2 second pause) … 1 BLINK … (6 second pause) …SEQUENCE REPEATS…

NOTE: The CM will only display one DTC at a time for each group.

FOR EXAMPLE: If two ‘20’ DTCs (DTCs 21 and 24) and one ‘30’ DTC (DTC 31) are stored, DTCs21 and 31 will display. After repairing the causes of DTCs 21 and 31, perform the memory eraseprocedure (CLEAR CODES) and repeat the ‘BLINK CODE’ activation procedure. This verifies therepair and displays any remaining DTCs.

TO CLEAR CODES:– Drive the vehicle at a speed greater than 19 mph (30 km/h).– Perform the ‘BLINK CODE’ procedure to verify the repairs and check that no other

DTCs are stored.

NOTES

1

DTC

(Blin

k C

ode)

Sum

mar

yTe

ves

Mar

k II

ABS

Syst

em:

Seda

n Ra

nge

thro

ugh

1994

MY;

XJS

Ran

ge u

p to

199

5 M

Y VI

N 1

9833

4

DT

Cs a

re s

tore

d in

th

e A

BS

co

ntr

ol m

od

ule

no

nvo

lati

le m

em

ory

.

TO A

CTIV

ATE

‘BLI

NK

COD

ES’ (

DTC

dis

play

):–

Switc

h th

e ig

nitio

n O

FF–

At th

e AB

S di

agno

stic

con

nect

or lo

cate

d in

whe

el a

rch

near

the

ABS

CM,

jum

p th

e N

/K (b

row

n / p

ink)

wire

pin

to th

e B

(bla

ck) w

ire p

in w

ith a

sho

rt JD

S ad

apte

r.–

Obs

erve

the

ABS

MIL

and

sw

itch

the

igni

tion

ON

.Th

e ‘B

LIN

K CO

DE’

seq

uenc

e w

ill be

gin

in s

ix s

econ

ds.

–Co

unt t

he fl

ashe

s (M

IL ‘B

LIN

KS’).

Eac

h di

git o

f the

DTC

is s

epar

ated

by

atw

o-se

cond

pau

se.

Indi

vidu

al D

TCs

are

sepa

rate

d by

a s

ix s

econ

d pa

use.

EXAM

PLE:

Sto

red

DTC

s 21

and

31

disp

lay

as fo

llow

s:IG

NIT

ION

ON

… (6

sec

ond

paus

e) …

2 BL

INKS

… (2

sec

ond

paus

e) …

1 B

LIN

K …

(6 s

econ

d pa

use)

…3

BLIN

KS …

(2 s

econ

d pa

use)

… 1

BLI

NK

… (6

sec

ond

paus

e) …

SEQ

UEN

CE R

EPEA

TS…

NO

TE

: Th

e CM

will

only

dis

play

one

DTC

at a

tim

e fo

r eac

h gr

oup.

FOR

EXAM

PLE:

If t

wo

‘20’

DTC

s (D

TCs

21 a

nd 2

4) a

nd o

ne ‘3

0’ D

TC (D

TC 3

1) a

re s

tore

d, D

TCs

21 a

nd 3

1 w

ill di

spla

y.Af

ter r

epai

ring

the

caus

es o

f DTC

s 21

and

31,

per

form

the

mem

ory

eras

e pr

oced

ure

(CLE

AR C

OD

ES)

and

repe

at th

e ‘B

LIN

K CO

DE’

act

ivat

ion

proc

edur

e. T

his

verif

ies

the

repa

ir an

d di

spla

ys a

ny re

mai

ning

DTC

s.

TO C

LEAR

CO

DES

:–

Driv

e th

e ve

hicl

e at

a s

peed

gre

ater

than

19

mph

(30

km/h

).–

Perfo

rm th

e ‘B

LIN

K CO

DE’

pro

cedu

re to

ver

ify th

e re

pairs

and

che

ck th

atno

oth

er D

TCs

are

stor

ed.

DT

CFA

ULT

DE

SC

RIP

TIO

NM

ON

ITO

RIN

G C

ON

DIT

ION

SA

BS

MIL

DE

FA

ULT

AC

TIO

NP

OS

SIB

LE

CA

US

ES

2

11AB

S CM

sel

f tes

t fai

lure

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

ABS

harn

ess

inco

rrect

con

nect

ion

CM fa

ilure

12AB

S CM

failu

reD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFCM

failu

re

21M

ain

valv

e fa

ilure

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Mai

n va

lve

to C

M c

ircui

t; op

en c

ircui

t, sh

ort c

ircui

t to

grou

nd o

rB+

vol

tage

Mai

n va

lve

grou

nd c

ircui

t; op

en c

ircui

t, hi

gh re

sist

ance

or s

hort

circ

uit t

o B+

vol

tage

Mai

n va

lve

failu

reCM

failu

re

22In

let v

alve

left

front

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Valv

e to

CM

circ

uit;

open

circ

uit,

shor

t circ

uit t

o gr

ound

or

B+ v

olta

geVa

lve

failu

reCM

failu

re

23O

utle

t val

ve le

ft fro

ntD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFVa

lve

to C

M c

ircui

t; op

en c

ircui

t, sh

ort c

ircui

t to

grou

nd o

rB+

vol

tage

Valv

e fa

ilure

CM fa

ilure

24In

let v

alve

righ

t fro

ntD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFVa

lve

to C

M c

ircui

t; op

en c

ircui

t, sh

ort c

ircui

t to

grou

nd o

rB+

vol

tage

Valv

e fa

ilure

CM fa

ilure

25O

utle

t val

ve ri

ght f

ront

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Valv

e to

CM

circ

uit;

open

circ

uit,

shor

t circ

uit t

o gr

ound

orB+

vol

tage

Valv

e fa

ilure

CM fa

ilure

26In

let v

alve

rear

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Valv

e to

CM

circ

uit;

open

circ

uit,

shor

t circ

uit t

o gr

ound

or

B+ v

olta

geVa

lve

failu

reCM

failu

re

27O

utle

t val

ve re

arD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFVa

lve

to C

M c

ircui

t; op

en c

ircui

t, sh

ort c

ircui

t to

grou

nd o

rB+

vol

tage

Valv

e fa

ilure

CM fa

ilure

31W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r to

CM c

ircui

t; op

en c

ircui

t or

trigg

er s

igna

l fai

lure

shor

t circ

uit t

o gr

ound

Whe

el s

peed

sen

sor f

ailu

reCM

failu

re

32W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Whe

el s

peed

sen

sor t

o CM

circ

uit;

open

circ

uit o

rtri

gger

sig

nal f

ailu

resh

ort c

ircui

t to

grou

ndW

heel

spe

ed s

enso

r fai

lure

CM fa

ilure

33W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r to

CM c

ircui

t; op

en c

ircui

t or

trigg

er s

igna

l fai

lure

shor

t circ

uit t

o gr

ound

Whe

el s

peed

sen

sor f

ailu

reCM

failu

re

34W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r to

CM c

ircui

t; op

en c

ircui

t or

trigg

er s

igna

l fai

lure

shor

t circ

uit t

o gr

ound

Whe

el s

peed

sen

sor f

ailu

reCM

failu

re

3

DT

CFA

ULT

DE

SC

RIP

TIO

NM

ON

ITO

RIN

G C

ON

DIT

ION

SA

BS

MIL

DE

FA

ULT

AC

TIO

NP

OS

SIB

LE

CA

US

ES

35W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

abov

e 25

mph

(40

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; int

erm

itten

t ope

n ci

rcui

t or

spee

d co

ntin

uity

sig

nal f

ailu

resh

ort c

ircui

t to

grou

ndIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

Loos

e w

heel

bea

rings

or d

amag

ed re

luct

orW

heel

spe

ed s

enso

r int

erm

itten

t fai

lure

Refe

r to

DTC

75

CM fa

ilure

36W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e ab

ove

25 m

ph (4

0 km

/h).

YES

OFF

Whe

el s

peed

sen

sor c

ircui

t to

CM; i

nter

mitt

ent o

pen

circ

uit o

rsp

eed

cont

inui

ty s

igna

l fai

lure

shor

t circ

uit t

o gr

ound

Inco

rrect

whe

el s

peed

sen

sor t

o re

luct

or a

ir ga

pLo

ose

whe

el b

earin

gs o

r dam

aged

relu

ctor

Whe

el s

peed

sen

sor i

nter

mitt

ent f

ailu

reRe

fer t

o D

TC 7

6CM

failu

re

37W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

abov

e 25

mph

(40

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; int

erm

itten

t ope

n ci

rcui

t or

spee

d co

ntin

uity

sig

nal f

ailu

resh

ort c

ircui

t to

grou

ndIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

Loos

e w

heel

bea

rings

or d

amag

ed re

luct

orW

heel

spe

ed s

enso

r int

erm

itten

t fai

lure

Refe

r to

DTC

77

CM fa

ilure

38W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; int

erm

itten

t ope

n ci

rcui

t or

spee

d co

ntin

uity

sig

nal f

ailu

resh

ort c

ircui

t to

grou

ndIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

Loos

e w

heel

bea

rings

or d

amag

ed re

luct

orW

heel

spe

ed s

enso

r int

erm

itten

t fai

lure

Refe

r to

DTC

78

CM fa

ilure

41W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; ope

n ci

rcui

t or

whe

el s

peed

com

paris

on fa

ilure

or n

o si

gnal

shor

t circ

uit t

o gr

ound

Inco

rrect

whe

el s

peed

sen

sor t

o re

luct

or a

ir ga

pW

heel

spe

ed s

enso

r fai

lure

CM fa

ilure

42W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Whe

el s

peed

sen

sor c

ircui

t to

CM; o

pen

circ

uit o

rw

heel

spe

ed c

ompa

rison

failu

re o

r no

sign

alsh

ort c

ircui

t to

grou

ndIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

Whe

el s

peed

sen

sor f

ailu

reCM

failu

re

43W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; ope

n ci

rcui

t or

whe

el s

peed

com

paris

on fa

ilure

or n

o si

gnal

shor

t circ

uit t

o gr

ound

Inco

rrect

whe

el s

peed

sen

sor t

o re

luct

or a

ir ga

pW

heel

spe

ed s

enso

r fai

lure

CM fa

ilure

44W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFW

heel

spe

ed s

enso

r circ

uit t

o CM

; ope

n ci

rcui

t or

whe

el s

peed

com

paris

on fa

ilure

or n

o si

gnal

shor

t circ

uit t

o gr

ound

Inco

rrect

whe

el s

peed

sen

sor t

o re

luct

or a

ir ga

pW

heel

spe

ed s

enso

r fai

lure

CM fa

ilure

51O

utle

t val

ve le

ft fro

nt h

ydra

ulic

failu

reD

rive

vehi

cle

abov

e 25

mph

(40

km/h

), ac

tivat

e AB

SYE

SO

FFO

utle

t val

ve h

ydra

ulic

failu

reRe

fer t

o D

TC 7

1CM

failu

re

52O

utle

t val

ve ri

ght f

ront

hyd

raul

ic fa

ilure

Driv

e ve

hicl

e ab

ove

25 m

ph (4

0 km

/h),

activ

ate

ABS

YES

OFF

Out

let v

alve

hyd

raul

ic fa

ilure

Refe

r to

DTC

72

CM fa

ilure

DT

CFA

ULT

DE

SC

RIP

TIO

NM

ON

ITO

RIN

G C

ON

DIT

ION

SA

BS

MIL

DE

FA

ULT

AC

TIO

NP

OS

SIB

LE

CA

US

ES

4

53 o

rO

utle

t val

ve re

ar h

ydra

ulic

failu

reD

rive

vehi

cle

abov

e 25

mph

(40

km/h

), ac

tivat

e AB

SYE

SO

FFO

utle

t val

ve h

ydra

ulic

failu

re54

Refe

r to

DTC

73

/ 74

CM fa

ilure

55W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFLo

ose

whe

el s

peed

sen

sor

no s

igna

l lon

g te

rmIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

CM fa

ilure

56W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Loos

e w

heel

spe

ed s

enso

rno

sig

nal l

ong

term

Inco

rrect

whe

el s

peed

sen

sor t

o re

luct

or a

ir ga

pCM

failu

re

57W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFLo

ose

whe

el s

peed

sen

sor

no s

igna

l lon

g te

rmIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

CM fa

ilure

58W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

abov

e 19

mph

(30

km/h

).YE

SO

FFLo

ose

whe

el s

peed

sen

sor

no s

igna

l lon

g te

rmIn

corre

ct w

heel

spe

ed s

enso

r to

relu

ctor

air

gap

CM fa

ilure

61Pr

essu

re s

witc

hes

Driv

e ve

hicl

e ab

ove

19 m

ph (3

0 km

/h).

YES

OFF

Pres

sure

sw

itche

s; s

hort

circ

uit t

o gr

ound

or B

+ vo

ltage

sign

al in

corre

ctRe

serv

oir t

o pr

essu

re s

witc

h to

CM

circ

uits

; sho

rt ci

rcui

t to

grou

nd o

r B+

volta

gePr

essu

re s

witc

h fa

ilure

Accu

mul

ator

, pum

p or

mot

or fa

ilure

CM fa

ilure

71W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h),

activ

ate

ABS.

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rRF

I sig

nal i

nter

fere

nce

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceRe

fer t

o D

TC 5

1CM

failu

re

72W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e be

low

25

mph

(40

km/h

), ac

tivat

e AB

S.*

Inte

rmitt

ent

INH

IBIT

EDSe

nsor

to C

M g

roun

d ci

rcui

t (sh

ield

ing)

; hig

h re

sist

ance

or

RFI s

igna

l int

erfe

renc

eop

en c

ircui

tCM

gro

und

circ

uit;

open

circ

uit o

r hig

h re

sist

ance

Refe

r to

DTC

52

CM fa

ilure

73W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h),

activ

ate

ABS.

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rRF

I sig

nal i

nter

fere

nce

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceRe

fer t

o D

TC 5

3CM

failu

re

74W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h),

activ

ate

ABS.

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rRF

I sig

nal i

nter

fere

nce

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceRe

fer t

o D

TC 5

4CM

failu

re

75W

heel

spe

ed s

enso

r lef

t fro

ntD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h).

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rsp

eed

cont

inui

ty s

igna

l fai

lure

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceAx

le v

ibra

tion,

inco

rrect

bea

ring

clea

ranc

e or

sen

sor a

ir ga

pRe

fer t

o D

TC 3

5CM

failu

re

* Lo

w P

riorit

y Fa

ult.

MIL

may

or m

ay n

ot a

ctiva

te d

epen

ding

on

othe

r fau

lt pa

ram

eter

s. D

TCs

will

be s

tore

d in

mem

ory.

5

DT

CFA

ULT

DE

SC

RIP

TIO

NM

ON

ITO

RIN

G C

ON

DIT

ION

SA

BS

MIL

DE

FA

ULT

AC

TIO

NP

OS

SIB

LE

CA

US

ES

76W

heel

spe

ed s

enso

r rig

ht fr

ont

Driv

e ve

hicl

e be

low

25

mph

(40

km/h

).*

Inte

rmitt

ent

INH

IBIT

EDSe

nsor

to C

M g

roun

d ci

rcui

t (sh

ield

ing)

; hig

h re

sist

ance

or

spee

d co

ntin

uity

sig

nal f

ailu

reop

en c

ircui

tCM

gro

und

circ

uit;

open

circ

uit o

r hig

h re

sist

ance

Axle

vib

ratio

n, in

corre

ct b

earin

g cl

eara

nce

or s

enso

r air

gap

Refe

r to

DTC

36

CM fa

ilure

77W

heel

spe

ed s

enso

r rig

ht re

arD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h).

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rsp

eed

cont

inui

ty s

igna

l fai

lure

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceAx

le v

ibra

tion,

inco

rrect

bea

ring

clea

ranc

e or

sen

sor a

ir ga

pRe

fer t

o D

TC 3

7CM

failu

re

78W

heel

spe

ed s

enso

r lef

t rea

rD

rive

vehi

cle

belo

w 2

5 m

ph (4

0 km

/h).

* In

term

itten

tIN

HIB

ITED

Sens

or to

CM

gro

und

circ

uit (

shie

ldin

g); h

igh

resi

stan

ce o

rsp

eed

cont

inui

ty s

igna

l fai

lure

open

circ

uit

CM g

roun

d ci

rcui

t; op

en c

ircui

t or h

igh

resi

stan

ceAx

le v

ibra

tion,

inco

rrect

bea

ring

clea

ranc

e or

sen

sor a

ir ga

pRe

fer t

o D

TC 3

8CM

failu

re

*Lo

w P

riorit

y Fa

ult.

MIL

may

or m

ay n

ot a

ctiva

te d

epen

ding

on

othe

r fau

lt pa

ram

eter

s. D

TCs

will

be s

tore

d in

mem

ory

abs brakes-teves mkii

Documents

abs system

antilock braking system

wheel lock

system description

system offuntil

normal system operation

brake system willfunction

abs control module abs