brake CHRYSLER VOYAGER 2001 Owner's Manual

INSTRUMENT CLUSTER - BLACK 13 WAYCAV CIRCUIT FUNCTION
1 E13 20OR/YL PANEL LAMPS DRIVER
2 L160 20WT/TN (LOW
LINE)RIGHT TURN INDICATOR DRIVER
3 G7 20VT/GY (HIGH LINE) LOW OIL PRESSURE INDICATOR DRIVER
4 G3 20VT/LB (HIGH LINE) MALFUNCTION INDICATOR LAMP DRIVER
5 L134 20WT/GY (HIGH
LINE)HIGH BEAM INDICATOR DRIVER
6 A701 16BR/RD FUSED B(+) (HAZARD)
7 Z108 18BK/LG GROUND
8 L161 20WT/LG (LOW
LINE)LEFT TURN INDICATOR DRIVER
9 D25 20WT/VT PCI BUS
10 B25 20DG/WT (RHD) PARK BRAKE SWITCH SENSE
10 B25 16DG/WT (LHD) PARK BRAKE SWITCH SENSE
11 G26 20VT/OR CHIME DRIVER
12 G150 20VT/BR INSTRUMENT CLUSTER WAKE UP SENSE
13 Z18 18BK/LB GROUND
INTELLIGENT POWER MODULE C1 - LT. GREEN/RED 20 WAYCAV CIRCUIT FUNCTION
1 F301 18VT/PK FUSED ACCESSORY RELAY OUTPUT
2- -
3- -
4 L43 18WT/DB LEFT LOW BEAM DRIVER
5 Z344 16BK/TN GROUND
6 L34 16WT/GY RIGHT HIGH BEAM DRIVER
7 W1 18BR/TN WASHER FLUID LEVEL SWITCH SENSE
8 L33 18WT/LG LEFT HIGH BEAM DRIVER
9 G31 18VT/LG (EXCEPT
BASE)AMBIENT TEMPERATURE SENSOR SIGNAL
10 L44 16WT/TN RIGHT LOW BEAM DRIVER
11 F300 18OR/PK FUSED ACCESSORY RELAY OUTPUT
12 - -
13 Z343 18BK/LG GROUND
14 - -
15 L78 18WT/OR FUSED PARK LAMP RELAY OUTPUT (RIGHT)
16 L77 18WT/BR FUSED PARK LAMP RELAY OUTPUT (LEFT)
17 - -
18 G931 18VT/BR (EXCEPT
BASE)AMBIENT TEMPERATURE SENSOR RETURN
19 W20 18BR/YL REAR WASHER PUMP MOTOR CONTROL
20 W10 18BR FRONT WASHER PUMP MOTOR CONTROL
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CONNECTOR PINOUTS

INTELLIGENT POWER MODULE C3 (GAS) - NATURAL/RED 20 WAYCAV CIRCUIT FUNCTION
1 Z115 20BK/OR (EATX)
(3.3L/3.8L)GROUND
1 Z115 18BK/OR (EATX)
(2.4L)GROUND
2 F1 18PK/WT (EATX) FCM OUTPUT (UNLOCK-RUN-START)
3 T751 18YL (EATX) IGNITION SWITCH OUTPUT (START)
4 T2 18DG/WT TRS REVERSE SENSE
5 T16 18YL/OR (EATX) TRANSMISSION CONTROL RELAY OUTPUT
6 T15 18YL/BR (EATX) TRANSMISSION CONTROL RELAY CONTROL
7 C3 18DB/YL A/C COMPRESSOR CLUTCH RELAY OUTPUT
8 K31 18BR FUEL PUMP RELAY CONTROL
9 C13 18LB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL
10 A104 18YL/RD (EATX) FUSED B(+)
11 - -
12 - -
13 D25 18WT/VT (EATX) PCI BUS (EATX)
14 T752 18DG/OR ENGINE STARTER MOTOR RELAY CONTROL
15 Z116 18BK/VT GROUND
16 K51 18BR/WT AUTOMATIC SHUTDOWN RELAY CONTROL
17 F202 18PK/GY IGNITION SWITCH OUTPUT (RUN-START)
18 K173 18BR/VT RADIATOR FAN RELAY CONTROL
19 F202 18PK/GY IGNITION SWITCH OUTPUT (RUN-START)
20 A109 18OR/RD FUSED B(+)
INTELLIGENT POWER MODULE C4 - BLUE 10 WAYCAV CIRCUIT FUNCTION
1 Z127 12BK/DG (GAS) GROUND
2 T750 12YL/GY ENGINE STARTER MOTOR RELAY OUTPUT
3 K342 16BR/WT (DIESEL) ECM/PCM RELAY OUTPUT
3 K342 16BR/WT (GAS) AUTOMATIC SHUTDOWN RELAY OUTPUT
4 F500 16DG/PK (EXCEPT
MTX))FUSED IGNITION SWITCH OUTPUT (RUN)
5- -
6 D25 16WT/VT (ANTILOCK
BRAKES)PCI BUS
7 A107 12TN/RD (ANTILOCK
BRAKES)FUSED B(+)
8 A111 12DG/RD (ANTILOCK
BRAKES)FUSED B(+)
9 A701 14BR/RD (GAS) B(+) (HAZARD FEED)
9 A710 14BR/RD (DIESEL) B(+) (HAZARD FEED)
10 - -
INTELLIGENT POWER MODULE C5 - BLACK 4 WAYCAV CIRCUIT FUNCTION
1 A1 4RD B(+)
2- -
3- -
4- -
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CONNECTOR PINOUTS

INTELLIGENT POWER MODULE C6 - NATURAL 10 WAYCAV CIRCUIT FUNCTION
1 A101 12VT/RD FUSED B(+)
2 Z117 16BK/WT GROUND
3 Z118 16BK/YL GROUND
4 A110 12OR/RD (POWER
SEAT)FUSED B(+)
5- -
6- -
7 C7 12DB FUSED FRONT BLOWER MOTOR RELAY OUTPUT
8 F307 16LB/PK (BATTERY
POSITION)FUSED B(+)
8 F307 16LB/PK (ACCESSO-
RY RELAY POSITION)FUSED ACCESORY RELAY OUTPUT
9 A113 12WT/RD (POWER
SLIDING DOOR)FUSED B(+)
10 - -
INTELLIGENT POWER MODULE C7 - BLACK/RED 20 WAYCAV CIRCUIT FUNCTION
1 C16 20DB/GY (EXCEPT
BUILT-UP-EXPORT)FUSED REAR WINDOW DEFOGGER RELAY OUTPUT
1 C16 18DB/GY (BUILT-UP-
EXPORT)FUSED REAR WINDOW DEFOGGER RELAY OUTPUT
2 T751 20YL (EXCEPT
BUILT-UP-EXPORT)IGNITION SWITCH OUTPUT (START)
2 T141 20YL/OR (BUILT-UP-
EXPORT)IGNITION SWITCH OUTPUT (START)
3 D25 20WT/VT PCI BUS
4 L13 20WT/YL (BUILT-UP-
EXPORT)HEADLAMP ADJUST SIGNAL
5 K32 18DB/YL (GAS) BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID CONTROL
6- -
7 W7 20BR/GY FRONT WIPER PARK SWITCH SENSE
8 B20 20DG/OR BRAKE FLUID LEVEL SWITCH SENSE
9 F201 18PK/OR FCM OUTPUT (RUN-START)
10 F214 18PK/LG FCM OUTPUT (RUN-START)
11 A106 20LB/RD FUSED B(+)
12 - -
13 F2 18PK/WT (GAS) FCM OUTPUT (UNLOCK-RUN-START)
14 - -
15 A114 16GY/RD FUSED B(+) (I.O.D.)
16 D23 20WT/BR FLASH PROGRAM ENABLE
17 L50 18WT/TN PRIMARY BRAKE SWITCH SIGNAL
18 X1 16DG/BR (PREMIUM 8
SPEAKER)NAME BRAND SPEAKER RELAY OUTPUT
19 X3 20DG/VT HORN SWITCH SENSE
20 F100 18PK/VT FCM OUTPUT (RUN)
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CONNECTOR PINOUTS

LEFT SLIDING DOOR LOCK MOTOR/AJAR SWITCH (MANUAL SLIDING DOOR) - BLACK 4 WAYCAV CIRCUIT FUNCTION
1 P5 20BK/DB LEFT SLIDING DOOR UNLOCK DRIVER
2 P32 20BK/TN LEFT SLIDING DOOR LOCK DRIVER
3 G77 20BK/DG LEFT SLIDING DOOR AJAR SWITCH SENSE
4 Z77 20BK GROUND
LEFT SLIDING DOOR MOTOR (POWER SLIDING DOOR) - BLACK 8 WAYCAV CIRCUIT FUNCTION
1- -
2 Q71 20TN/VT LEFT DOOR MOTOR HALL EFFECT SUPPLY
3 Q69 16TN/OR LEFT SLIDING DOOR CLOSE DRIVER
4 Z163 18BK/TN GROUND
5 Q63 18OR/TN LEFT DOOR MOTOR CLUTCH DRIVER
6 Q67 16TN/BR LEFT SLIDING DOOR OPEN DRIVER
7 Z33 20BK/TN GROUND
8 Q73 20TN/YL LEFT DOOR MOTOR HALL EFFECT SIGNAL
LEFT STOP/TURN SIGNAL RELAY (TRAILER TOW) - BLACK 5 WAYCAV CIRCUIT FUNCTION
1 L50 18WT/TN PRIMARY BRAKE SWITCH SIGNAL
1 L50 18WT/TN PRIMARY BRAKE SWITCH SIGNAL
2 Z1 18BK/DG GROUND
2 Z1 18BK/DG GROUND
3 L73 18YL LEFT STOP SIGNAL
4 L63 18WT/DG LEFT REAR TURN SIGNAL DRIVER
4 L63 18WT/DG LEFT REAR TURN SIGNAL DRIVER
5 L615 18OR LEFT COMBINATION SIGNAL
LEFT VISOR/VANITY LAMP (PREMIUM/LUXURY) - BLACK 2 WAYCAV CIRCUIT FUNCTION
A Z327 20BK/OR GROUND
B M27 20YL/LB READING LAMP DRIVER
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1055
CONNECTOR PINOUTS

FRONT CONTROL MODULE - BLACK 49 WAYCAV CIRCUIT FUNCTION
1 A1 B(+)
2 A1 B(+)
3 L43 LEFT LOW BEAM DRIVER
4 L34 RIGHT HIGH BEAM DRIVER
5 L33 LEFT HIGH BEAM DRIVER
6 L44 RIGHT LOW BEAM DRIVER
7 - NOT USED
8 Z117, Z118, Z343, Z344 GROUND
9 A1 B(+)
10 FCM 10 HORN RELAY CONTROL
11 FCM 11 NAME BRAND SPEAKER RELAY CONTROL
12 - SPARE
13 FCM 13 PARK LAMP RELAY CONTROL
14 FCM 14 FRONT WIPER ON/OFF RELAY CONTROL
15 C41 (DIESEL) CABIN HEATER ASSIST CONTROL
16 W7 FRONT WIPER PARK SWITCH SENSE
17 X3 HORN SWITCH SENSE
18 W1 WASHER FLUID LEVEL SWITCH SENSE
19 FCM 19 (GAS) IGNITION SWITCH OUTPUT (START)
20 A114 FUSED B(+) (I.O.D.)
21 L78 FUSED PARK LAMP RELAY OUTPUT (RIGHT)
22 D25 PCI BUS
23 G931 AMBIENT TEMPERATURE SENSOR RETURN
24 - SPARE
25 G31 AMBIENT TEMPERATURE SENSOR SIGNAL
26 L13 (RG) HEADLAMP ADJUST SIGNAL
27 F1, F2 FCM OUTPUT (UNLOCK-RUN-START)
28 F214 FCM OUTPUT (RUN-START) (SIACM)
29 F100 FCM OUTPUT (RUN) (ORC)
30 FCM 30 FRONT/REAR BLOWER MOTOR RELAY CONTROL
31 FCM 31 REAR WINDOW DEFOGGER RELAY CONTROL
32 FCM 32 (BUILT-UP-
EXPORT))HEADLAMP WASHER RELAY CONTROL
33 FCM 33 FRONT FOG LAMP RELAY CONTROL
34 FCM 34 FRONT WIPER HIGH/LOW RELAY CONTROL
35 FCM 35 ACCESSORY RELAY CONTROL (RUN-ACC)
36 B20 BRAKE FLUID LEVEL SWITCH SENSE
37 F20 IGNITION SWITCH OUTPUT (RUN-START)
38 A1 B(+)
39 T2 TRS REVERSE SENSE
40 T753 (DIESEL) IGNITION SWITCH OUTPUT (START)
41 L77 FUSED PARK LAMP RELAY OUTPUT (LEFT)
42 D23 FLASH PROGRAM ENABLE
43 Z116 GROUND
44 L50 PRIMARY BRAKE SWITCH SIGNAL
45 W10 FRONT WASHER PUMP MOTOR CONTROL
46 W20 REAR WASHER PUMP MOTOR CONTROL
47 K32 BRAKE TRANSMISSION SHIFT INTERLOCK SOLENOID CONTROL
48 F201 FCM OUTPUT (RUN-START) (ORC)
49 - NOT USED
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CONNECTOR PINOUTS

POWERTRAIN CONTROL MODULE C2 (2.4L/3.3L/3.8L) - GRAY/GRAY 40 WAYCAV CIRCUIT FUNCTION
41 V37 18VT SPEED CONTROL SWITCH SIGNAL
42 C18 18LB/BR A/C PRESSURE SENSOR SIGNAL
43 K900 18DB/DG SENSOR GROUND
44 F888 18BR/PK 8 VOLT SUPPLY
45 - -
46 A109 18OR/RD FUSED B(+)
47 - -
48 K40 18BR/LG (2.4L) IDLE AIR CONTROL NO. 3 DRIVER
49 K60 18VT/LG (2.4L) IDLE AIR CONTROL NO. 2 DRIVER
49 K39 18VT/DG (3.3L/3.8L) IDLE AIR CONTROL NO. 1 DRIVER
50 Z131 18BK/DG GROUND
51 K141 18DB/YL OXYGEN SENSOR 1/2 SIGNAL
52 - -
53 - -
54 - -
55 - -
56 V36 18VT/YL SPEED CONTROL VACUUM SOLENOID CONTROL
57 K39 18VT/DG (2.4L) IDLE AIR CONTROL NO. 1 DRIVER
57 K60 18VT/LG (3.3L/3.8L) IDLE AIR CONTROL NO. 2 DRIVER
58 K59 18BR/DG (2.4L) IDLE AIR CONTROL NO. 4 DRIVER
59 D25 18WT/VT PCI BUS
60 - -
61 F855 18PK/YL 5 VOLT SUPPLY
62 B29 18DG/WT SECONDARY BRAKE SWITCH SIGNAL
63 T10 18DG/LG (EATX) TORQUE MANAGEMENT REQUEST SENSE
64 C13 18LB/OR A/C COMPRESSOR CLUTCH RELAY CONTROL
65 D21 18WT/BR SCI TRANSMIT
66 N7 18DB/OR VEHICLE SPEED SENSOR SIGNAL
67 K51 18BR/WT AUTOMATIC SHUTDOWN RELAY CONTROL
68 K52 18DB/WT EVAPORATIVE EMISSION SOLENOID CONTROL
69 - -
70 K70 18DB/BR EVAPORATIVE EMISSION SOLENOID SENSE
71 - -
72 K107 18VT/WT (EXCEPT
BUILT-UP-EXPORT)LEAK DETECTION PUMP SWITCH SENSE
73 K173 18BR/VT RADIATOR FAN RELAY CONTROL
74 K31 18BR FUEL PUMP RELAY CONTROL
75 D20 18WT/LG SCI RECEIVE
76 T41 18YL/DB PARK/NEUTRAL POSITION SWITCH SENSE (TRS T41)
77 K106 18VT/LB (EXCEPT
BUILT-UP-EXPORT)LEAK DETECTION PUMP SOLENOID CONTROL
78 K54 18DB/WT (ATX) TORQUE CONVERTER CLUTCH SOLENOID CONTROL
79 - -
80 V35 18VT/OR SPEED CONTROL VENT SOLENOID CONTROL
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CONNECTOR PINOUTS

TABLE OF CONTENTS
1.0 INTRODUCTION.........................................................1
1.1SYSTEM COVERAGE...............................................1
1.2SIX-STEP TROUBLESHOOTING PROCEDURE..........................1
2.0 IDENTIFICATION OF SYSTEM.............................................1
3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION......................1
3.1TEVES MARK 20 SYSTEM DESCRIPTION..............................1
3.2TRACTION CONTROL SYSTEM (TCS) DESCRIPTION....................1
3.3SYSTEM COMPONENTS.............................................2
3.3.1ABS AND BRAKE WARNING INDICATORS.......................2
3.3.2CONTROLLER ANTILOCK BRAKE (CAB)........................2
3.3.3HYDRAULIC CONTROL UNIT..................................3
3.3.4SWITCHES/SENSORS........................................3
3.3.5SYSTEM INITIALIZATION.....................................3
3.3.6DIAGNOSTIC MODE.........................................4
3.4DIAGNOSTIC TROUBLE CODES......................................4
3.5DRBIIITERROR MESSAGES AND BLANK SCREEN......................4
3.5.1DRBIIITDOES NOT POWER UP................................4
3.5.2DISPLAY IS NOT VISIBLE.....................................4
4.0 DISCLAIMERS, SAFETY, WARNINGS.......................................5
4.1DISCLAIMERS......................................................5
4.2SAFETY...........................................................5
4.2.1TECHNICIAN SAFETY INFORMATION...........................5
4.2.2VEHICLE PREPARATION FOR TESTING.........................5
4.2.3SERVICING SUB-ASSEMBLIES................................5
4.2.4DRBIIITSAFETY INFORMATION...............................5
4.3WARNINGS........................................................6
4.3.1VEHICLE DAMAGE WARNINGS................................6
4.3.2ROAD TESTING A COMPLAINT VEHICLE........................6
4.4DIAGNOSIS........................................................6
5.0 REQUIRED TOOLS AND EQUIPMENT......................................6
6.0 GLOSSARY OF TERMS...................................................7
7.0 DIAGNOSTIC INFORMATION AND PROCEDURES............................9
BRAKES (CAB)
BUS SYSTEM COMMUNICATION FAILURE.................................10
CAB INTERNAL FAILURE................................................11
CLUSTER LAMP FAILURE................................................12
LEFT FRONT SENSOR CIRCUIT FAILURE..................................14
LEFT REAR SENSOR CIRCUIT FAILURE...................................14
RIGHT FRONT SENSOR CIRCUIT FAILURE.................................14
RIGHT REAR SENSOR CIRCUIT FAILURE..................................14
LEFT FRONT WHEEL SPEED SIGNAL FAILURE.............................17
LEFT REAR WHEEL SPEED SIGNAL FAILURE..............................19
PUMP CIRCUIT FAILURE................................................21
RIGHT FRONT WHEEL SPEED SIGNAL FAILURE............................24
i

TABLE OF CONTENTS - Continued
RIGHT REAR WHEEL SPEED SIGNAL FAILURE.............................26
SYSTEM OVERVOLTAGE................................................28
SYSTEM UNDERVOLTAGE...............................................30
VALVE POWER FEED FAILURE...........................................32
*BRAKE LAMP SWITCH..................................................35
*TRAC OFF INDICATOR NEVER/ALWAYS ON...............................36
*TRAC ON INDICATOR NEVER/ALWAYS ON................................39
VERIFICATION TESTS
VERIFICATION TESTS...................................................40
8.0 COMPONENT LOCATIONS...............................................41
8.1CONTROLLER ANTILOCK BRAKE (CAB)..............................41
8.2DATA LINK CONNECTOR...........................................41
8.3FUSES...........................................................42
8.4TRACTION CONTROL SWITCH......................................42
8.4.1TRACTION CONTROL INDICATORS...........................43
8.5WHEEL SPEED SENSORS..........................................43
8.5.1FRONT....................................................43
8.5.2REAR.....................................................44
8.5AWHEEL SPEED SENSOR CONNECTORS..............................44
8.5A.1FRONT....................................................44
8.5A.2REAR.....................................................45
8.6BRAKE LAMP SWITCH.............................................45
9.0 CONNECTOR PINOUTS.................................................47
CONTROLLER ANTILOCK BRAKE - BLACK 24 WAY..........................47
DATA LINK CONNECTOR - WHITE 16 WAY.................................47
DIAGNOSTIC JUNCTION PORT - BLACK 16 WAY............................48
INTELLIGENT POWER MODULE C4 - GRAY 10 WAY.........................48
LEFT FRONT WHEEL SPEED SENSOR - BLACK 2 WAY......................48
LEFT FRONT WHEEL SPEED SENSOR CONNECTOR (SENSOR SIDE)-2WAY..49
LEFT REAR WHEEL SPEED SENSOR - BLACK 2 WAY........................49
LEFT REAR WHEEL SPEED SENSOR CONNECTOR (SENSOR SIDE)-2WAY ...49
FUSES (IPM)...........................................................51
PUMP MOTOR CONNECTOR-2WAY.....................................52
RIGHT FRONT WHEEL SPEED SENSOR - GRAY 2 WAY......................52
RIGHT FRONT WHEEL SPEED SENSOR CONNECTOR
(SENSOR SIDE)-2WAY.................................................52
RIGHT REAR WHEEL SPEED SENSOR - BLACK 2 WAY......................52
RIGHT REAR WHEEL SPEED SENSOR CONNECTOR (SENSOR SIDE)-2WAY..53
TRACTION CONTROL SWITCH - BLACK 2 WAY.............................53
10.0 SCHEMATIC DIAGRAMS.................................................55
TEVES MARK 20 ANTILOCK BRAKE SYSTEM........................55
ii

1.0 INTRODUCTION
The procedures contained in this manual include
all the specifications, instructions, and graphics
needed to diagnose Mark 20 Antilock Braking Sys-
tem (ABS) and Mark 20 Antilock Braking System
with Traction Control. The diagnostics in this man-
ual are based on the failure condition or symptom
being present at time of diagnosis.
Please follow the recommendations below when
choosing your diagnostic path.
1. First make sure the DRBIIItis communicating
with the CAB. If the DRBIIItdisplays a ªNo
Responseº condition, you must diagnose that
first.
2. Read DTC's (diagnostic trouble codes) with the
DRBIIIt.
3. If no DTC's are present, identify the customer
complaint.
4. Once the DTC or customer complaint is identi-
fied, locate the matching test in the Table of
Contents and begin to diagnose the symptom.
All component location views are in Section 8.0.
All connector pinouts are in Section 9.0. All sche-
matics are in Section 10.0.
An * placed before the symptom description indi-
cates a concern with no associated DTC.
When repairs are required, refer to the appropri-
ate service manual for the proper removal and
repair procedure.
Diagnostic procedures change every year. New
diagnostic systems may be added; carry over sys-
tems may be enhanced. READ THIS MANUAL
BEFORE TRYING TO DIAGNOSE A VEHICLE
CODE. It is recommended that you review the
entire manual to become familiar with all new and
changed diagnostic procedures.
After using this book, if you have any comments
or recommendations, please fill out the form at the
back of the book and mail it back to us.
1.1 SYSTEM COVERAGE
This diagnostic procedure manual covers the an-
tilock braking system (ABS) and traction control
system found on: 2001 Chrysler Town and Country,
Dodge Caravan and Grand Caravan.
1.2 SIX-STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the controller antilock brake module
is done in six basic steps:
²verification of complaint
²verification of any related symptoms
²symptom analysis
²problem isolation
²repair of isolated problem
²verification of proper operation
2.0 IDENTIFICATION OF
SYSTEM
Vehicles equipped with the Teves Mark 20 an-
tilock brake system can be identified by the pres-
ence of the controller antilock brake module located
beneath the master cylinder.
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
3.1 TEVES MARK 20 SYSTEM
DESCRIPTION
The controller antilock brake module is used to
monitor wheel speeds and to modulate (control)
hydraulic pressure in each brake channel. The
modulated hydraulic pressure is used to prevent
wheel lock-up during braking.
The Teves Mark 20 system uses a diagonal split
hydraulic brake system.
In the standard brake mode
the master cylinder primary circuit supplies pressure
to the right front and left rear wheel brakes, and the
secondary master cylinder circuit supplies pressure
to the left front and right rear wheel brakes.
3.2 TRACTION CONTROL SYSTEM (TCS)
DESCRIPTION
The main purpose of traction control is to reduce
wheel slip and maintain traction at the driven
wheels when road surfaces are slippery. The trac-
tion control system reduces wheel slip by braking
the wheel that is losing traction. The system is
designed to operate at speeds below 56 km/h (35
mph).
The Controller Antilock Brake (CAB) monitors
wheel speeds. If, during acceleration, the module
detects front (drive) wheel slip and the brakes are
not applied, the CAB will enter traction control
mode. Traction control works in the following order
when drive wheel slip is detected.
1. Close the (normally open) isolation valves.
2. Start pump/motor and supply volume/pressure
to front hydraulic circuits (pump runs continu-
ously during traction control).
3. Open and close build and decay valves to main-
tain minimum wheel slip and maximum trac-
tion.
1
GENERAL INFORMATION

The cycling of the build and decay valves is
similar to the ABS except that they work to control
wheel spin by applying brakes. ABS function is to
control wheel skid by releasing brakes.
Two pressure relief valves allow excess fluid vol-
ume to return to the reservoir when not used by the
build/decay cycles. These are required because the
pump supplies more volume than the traction con-
trol system requires.
If at any time the brake pedal is applied during a
traction control cycle, the brake lamp switch will
trigger the CAB to switch off the traction control.
The traction control system will be enabled at
each ignition cycle. It may be turned off by depress-
ing the Traction Control Switch. The traction con-
trol system function lamp will illuminate ªTRAC
OFFº immediately upon depressing the traction
control switch button. Only the ªTRACº portion of
the ªTRAC OFFº indicator will illuminate during a
traction control event. If the CAB calculates that
the brake temperatures are high, the traction con-
trol system will become inoperative until a time-out
period has elapsed. When in this thermal protection
mode, the traction control ªTRAC OFFº lamp will
illuminate; however, a fault will not be registered.
3.3 SYSTEM COMPONENTS
²controller antilock brake (CAB)
²vacuum booster
²master cylinder
²ABS integrated electronic control module/
hydraulic control unit (HCU), valve block assem-
bly: 8 valve solenoids (4 inlet valves, 4 outlet
valves, 2 accumulators) 1 motor, 2 pump
²ABS integrated electronic control module with
traction control same as above but has 10 valve
solenoids.
²4 wheel speed sensor/tone wheel assemblies
²ABS warning indicator
²fuses and wiring harness
²fluid reservoir
²TRAC/TRAC OFF indicator
3.3.1 ABS AND BRAKE WARNING
INDICATORS
The amber ABS warning indicator is located in
the instrument cluster. It is used to inform the
driver that the antilock function has been turned
off. The ABS warning indicator is controlled by the
CAB. The CAB controls the lamp with a command
over the PCI bus.
The ABS Warning Indicator will remain lit during
every key cycle until a circuit or component fault is
repaired and the CAB no longer detects the fault.After repair of a sensor signal fault or a pump motor
fault, the CAB must sense all four wheels at 25
km/h (15 mph) before it will extinguish the ABS and
TRAC OFF Indicators.
The Instrument Cluster will illuminate the ABS
Warning Indicator if it loses communication with
the CAB.
The red BRAKE warning indicator is also located
in the instrument cluster. It can be activated in
several ways. Application of the parking brake or a
low fluid signal from the fluid level switch located in
the master cylinder reservoir will cause the indica-
tor to come on.
3.3.2 CONTROLLER ANTILOCK BRAKE
(CAB)
The Controller Antilock Brake (CAB) is a
microprocessor-based device that monitors wheel
speeds and controls the antilock functions. The
CAB contains two microprocessors that receive
identical sensor signals and then independently
process the information. The results are then com-
pared to make sure that they agree. Otherwise, the
CAB will turn off the antilock and turn on the ABS
amber warning indicator.
The primary functions of the CAB are to:
²detect wheel locking tendencies
²control fluid pressure modulation to the brakes
during antilock stop
²monitor the system for proper operation
²manage traction control functions
²provide communication to the DRBIIItwhile in
diagnostic mode
²store diagnostic information in non-volatile memory
The CAB continuously monitors the speed of each
wheel. When a wheel locking tendency is detected,
the CAB will command the appropriate valve to
modulate brake fluid pressure in its hydraulic unit.
Brake pedal position is maintained during an an-
tilock stop by being a closed system with the use of
2 accumulators. The CAB continues to control pres-
sure in individual hydraulic circuits until a wheel
locking tendency is no longer present. The CAB
turns on the pump motor during an antilock stop.
The antilock brake system is constantly moni-
tored by the CAB for proper operation. If the CAB
detects a system malfunction, it can disable the
antilock system and turn on the ABS warning
indicator. If the antilock function is disabled, the
system will revert to standard base brake system
operation.
The CAB inputs include the following:
²diagnostic communication
²four wheel speed sensors
2
GENERAL INFORMATION