ABS CHRYSLER VOYAGER 2001 Owners Manual

(12) Install the wheel speed sensor on the hub/
bearing and adapter. Install the wheel speed sensor
attaching bolt (Fig. 89). Tighten the wheel speed sen-
sor attaching bolt to a torque of 12 N´m (105 in. lbs).
(13) Install the park brake cable into its mounting
hole in the adapter.Be sure all the locking tabs
on the park brake cable retainer are expanded
out to ensure the cable will not pull out of the
adapter.
(14) Install the end of the park brake cable on the
park brake actuator lever (Fig. 87).
NOTE: The horseshoe clip must be installed and
installed properly when the park brake cable is
installed in the adapter. The purpose of the horse-
shoe clip is to prevent park brake cable retainer
from moving in the adapter. If horseshoe clip is not
installed the park brake cable retainer will rattle in
the adapter.
(15) Install aNEWhorseshoe clip on the park
brake cable retainer (Fig. 87). The horseshoe clip is
installed between the retainer for the park brake
cable and the adapter. Horseshoe clip must be
installed with the curved end of the clip pointing
straight up and the edge of the curved end facing
toward the rear of the vehicle (Fig. 87).
(16) Remove the locking pliers (Fig. 83) from the
front park brake cable.
(17) Adjust the park brake drum-in-hat brake
shoes. (Refer to 5 - BRAKES/PARKING BRAKE/
SHOES - ADJUSTMENTS).
(18) Install the rotor on the hub/bearing.
(19) Carefully lower caliper and brake shoes over
rotor and onto the adapter using the reverse proce-
dure for removal (Fig. 85).
CAUTION: When installing guide pin bolts extreme
caution should be taken not to crossthread the cal-
iper guide pin bolts.
(20) Install the caliper guide pin bolts (Fig. 84).
Tighten the guide pin bolts to a torque of 22 N´m
(192 in. lbs.).
(21) Clean all foreign material off the threads of
the outer C/V joint stub shaft. Install the washer and
hub nut (Fig. 82) on the stub shaft of the outer C/V
joint.
(22) Set the parking brake.
(23) Tighten the hub nut to a torque of 244 N´m
(180 ft. lbs.).
(24) Install the spring washer (Fig. 81) on the stub
shaft of the outer C/V joint.
(25) Install the nut retainer and cotter pin (Fig.
80) on the stub shaft of the outer C/V joint.
(26) Install the wheel and tire assembly. Tighten
the wheel mounting stud nuts in proper sequenceuntil all nuts are torqued to half specification. Then
repeat the tightening sequence to the full specified
torque of 135 N´m (100 ft. lbs.).
(27) Lower vehicle.
(28) Fully apply and release the park brake pedal
one time. This will seat and correctly adjust the park
brake cables.
CAUTION: Before moving vehicle, pump the brake
pedal several times to insure the vehicle has a firm
brake pedal to adequately stop vehicle.
(29) Road test the vehicle and make several stops
to wear off any foreign material on the brakes and to
seat the brake shoe linings.
ADJUSTMENT - PARKING BRAKE SHOES
CAUTION: Before adjusting the park brake shoes be
sure that the park brake pedal is in the fully
released position. If park brake pedal is not in the
fully released position, the park brake shoes can
not be accurately adjusted.
(1) Raise vehicle.
(2) Remove tire and wheel.
(3) Remove disc brake caliper from caliper adapter
(Fig. 100). (Refer to 5 - BRAKES/HYDRAULIC/ME-
CHANICAL/DISC BRAKE CALIPERS - REMOVAL).
(4) Remove rotor from hub/bearing.
Fig. 100 Disc Brake Caliper
1 - DISC BRAKE CALIPER
2 - ADAPTER
3 - AXLE
4 - GUIDE PIN BOLTS
5 - DRIVESHAFT (AWD MODELS ONLY)
RSBRAKES - BASE5-59
SHOES (Continued)

BRAKES - ABS
TABLE OF CONTENTS
page page
BRAKES - ABS
DESCRIPTION...........................67
OPERATION.............................67
CAUTION...............................69
STANDARD PROCEDURE..................70
ANTILOCK BRAKE SYSTEM BLEEDING.....70
SPECIFICATIONS........................71
FRONT WHEEL SPEED SENSOR
REMOVAL..............................71
INSTALLATION...........................71
REAR WHEEL SPEED SENSOR - AWD
REMOVAL..............................72
INSTALLATION...........................72
REAR WHEEL SPEED SENSOR - FWD
REMOVAL..............................73INSTALLATION...........................74
TONE WHEEL
INSPECTION............................74
TRACTION CONTROL SWITCH
DIAGNOSIS AND TESTING.................74
TRACTION CONTROL SWITCH............74
ICU (INTEGRATED CONTROL UNIT)
DESCRIPTION...........................75
OPERATION.............................75
REMOVAL..............................76
DISASSEMBLY...........................77
ASSEMBLY.............................77
INSTALLATION...........................77
BRAKES - ABS
DESCRIPTION - ANTILOCK BRAKE SYSTEM
This section covers the physical and operational
descriptions and the on-car service procedures for the
Mark 20e Antilock Brake System and the Mark 20e
Antilock Brake System with traction control.
The purpose of the antilock brake system (ABS) is
to prevent wheel lockup under braking conditions on
virtually any type of road surface. Antilock braking is
desirable because a vehicle that is stopped without
locking the wheels retains directional stability and
some steering capability. This allows the driver to
retain greater control of the vehicle during braking.
DESCRIPTION - ELECTRONIC BRAKE
DISTRIBUTION
Vehicles equipped with ABS use electronic brake
distribution (EBD) to balance front-to-rear braking.
The EBD is used in place of a rear proportioning
valve. The EBD system uses the ABS system to con-
trol the slip of the rear wheels in partial braking
range. The braking force of the rear wheels is con-
trolled electronically by using the inlet and outlet
valves located in the integrated control unit (ICU).
DESCRIPTION - TRACTION CONTROL SYSTEM
Traction control reduces wheel slip and maintains
traction at the driving wheels at speeds below 56
km/h (35 mph) when road surfaces are slippery. The
traction control system reduces wheel slip by braking
the wheel that is losing traction.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves are
included on vehicles with traction control. These
valves are located inside the HCU and cannot be ser-
viced separately from the HCU.
TRACTION CONTROL LAMP
The traction control function lamp is located in the
transmission range indicator display of the instru-
ment cluster, displaying TRAC, TRAC OFF or nei-
ther depending on system mode.
The TRAC OFF lamp is controlled by a Traction
Control Off switch that is a momentary contact type
switch. The Traction Control Off switch is located on
the steering column upper shroud.
OPERATION - ANTILOCK BRAKE SYSTEM
There are a few performance characteristics of the
Mark 20e Antilock Brake System that may at first
seem abnormal, but in fact are normal. These char-
acteristics are described below.
NORMAL BRAKING
Under normal braking conditions, the ABS func-
tions the same as a standard base brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS BRAKING
ABS operation is available at all vehicle speeds
above 3±5 mph. If a wheel locking tendency is
detected during a brake application, the brake sys-
RSBRAKES - ABS5-67

tem enters the ABS mode. During ABS braking,
hydraulic pressure in the four wheel circuits is mod-
ulated to prevent any wheel from locking. Each
wheel circuit is designed with a set of electric sole-
noids to allow modulation, although for vehicle sta-
bility, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three control channels.
During antilock operation of the vehicle's brake sys-
tem, the front wheels are controlled independently
and are on two separate control channels, and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the controller antilock brake (CAB).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is due to pressurized fluid
being transferred between the master cylinder and
the brakes. If ABS operation occurs during hard
braking, some pulsation may be felt in the vehicle
body due to fore and aft movement of the suspension
as brake pressures are modulated.
At the end of an ABS stop, ABS is turned off when
the vehicle is slowed to a speed of 3±4 mph. There
may be a slight brake pedal drop anytime that the
ABS is deactivated, such as at the end of the stop
when the vehicle speed is less than 3 mph or during
an ABS stop where ABS is no longer required. These
conditions exist when a vehicle is being stopped on a
road surface with patches of ice, loose gravel, or sand
on it. Also, stopping a vehicle on a bumpy road sur-
face activates ABS because of the wheel hop caused
by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, some wheel slip is desired in order to achieve
optimum braking performance. Wheel slip is defined
as follows: 0 percent slip means the wheel is rolling
freely and 100 percent slip means the wheel is fully
locked. During brake pressure modulation, wheel slip
is allowed to reach up to 25±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may be
noticeable as light patched marks.
START-UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
The ABS warning lamp will also be on for up to 5
seconds after the ignition is turned on. When the
vehicle is first driven off, a humming may be heard
or felt by the driver at approximately 20±40 kph
(12±25 mph). All of these conditions are a normal
function of ABS as the system is performing a diag-
nosis check.
PREMATURE ABS CYCLING
Symptoms of premature ABS cycling include: click-
ing sounds from the solenoid valves; pump/motor
running; and pulsations in the brake pedal. Prema-
ture ABS cycling can occur at any braking rate of the
vehicle and on any type of road surface. Neither the
red BRAKE warning lamp, nor the amber ABS warn-
ing lamp, illuminate and no fault codes are stored in
the CAB.
Premature ABS cycling is a condition that needs to
be correctly assessed when diagnosing problems with
the antilock brake system. It may be necessary to use
a DRB scan tool to detect and verify premature ABS
cycling.
Check the following common causes when diagnos-
ing premature ABS cycling: damaged tone wheels;
incorrect tone wheels; damaged steering knuckle
wheel speed sensor mounting bosses; loose wheel
speed sensor mounting bolts; excessive tone wheel
runout; or an excessively large tone wheel-to-wheel
speed sensor air gap. Give special attention to these
components when diagnosing a vehicle exhibiting
premature ABS cycling.
After diagnosing the defective component, repair or
replace it as required. When the component repair or
replacement is completed, test drive the vehicle to
verify that premature ABS cycling has been cor-
rected.
OPERATION - ELECTRONIC BRAKE
DISTRIBUTION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure, the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
hydraulic control unit (HCU) resulting in a drop in
fluid pressure to the rear brakes. In order to increase
5 - 68 BRAKES - ABSRS
BRAKES - ABS (Continued)

the rear brake pressure, the outlet valve is switched
off and the inlet valve is pulsed. This increases the
pressure to the rear brakes. This back-and-forth pro-
cess will continue until the required slip difference is
obtained. At the end of EBD braking (brakes
released) the fluid in the LPA drains back to the
master cylinder by switching on the outlet valve and
draining through the inlet valve check valve. At the
same time the inlet valve is switched on in case of
another brake application.
The EBD will remain functional during many ABS
fault modes. If both the red BRAKE, and amber ABS
warning indicators are illuminated, the EBD may not
be functioning.
OPERATION - TRACTION CONTROL SYSTEM
The traction control module monitors wheel speed.
During acceleration, if the module detects front
(drive) wheel slip and the brakes are not applied, the
module enters traction control mode. Traction control
operation proceeds in the following order:
(1) Close the normally open isolation valves.
(2) Start the pump/motor and supply volume and
pressure to the front (drive) hydraulic circuit. (The
pump/motor runs continuously during traction con-
trol operation.)
(3) Open and close the build and decay valves to
maintain minimum wheel slip and maximum trac-
tion.
The cycling of the build and decay valves during
traction control is similar to that during antilock
braking, except the valves work to control wheel spin
by applying the brakes, whereas the ABS function is
to control wheel skid by releasing the brakes.
If the brakes are applied at anytime during a trac-
tion control cycle, the brake lamp switch triggers the
controller to switch off traction control.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves allow
pressure and volume to return to the master cylinder
reservoir when not consumed by the build and decay
valves. These valves are necessary because the
pump/motor supplies more volume than the system
requires.
TRACTION CONTROL LAMP
The traction control system is enabled at each igni-
tion cycle. It may be turned off by depressing the
Traction Control Off switch button when the ignition
is in the ON position. The traction control function
lamp (TRAC OFF) illuminates immediately upon
depressing the button.
The traction control function lamp illuminates dur-
ing a traction control cycle, displaying TRAC.If the CAB calculates that the brake temperatures
are high, the traction control system becomes inoper-
ative until a time-out period has elapsed. During this
ªthermo-protection mode,º the traction control func-
tion lamp illuminates TRAC OFF; note that no trou-
ble code is registered.
CAUTION
The ABS uses an electronic control module, the
CAB. This module is designed to withstand normal
current draws associated with vehicle operation.
Care must be taken to avoid overloading the CAB
circuits.
CAUTION: In testing for open or short circuits, do
not ground or apply voltage to any of the circuits
unless instructed to do so for a diagnostic proce-
dure.
CAUTION: These circuits should only be tested
using a high impedance multi-meter or the DRBIIIT
scan tool as described in this section. Power
should never be removed or applied to any control
module with the ignition in the ON position. Before
removing or connecting battery cables, fuses, or
connectors, always turn the ignition to the OFF
position.
CAUTION: The CAB 24-way connector should never
be connected or disconnected with the ignition
switch in the ON position.
CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of aftermarket electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, etc.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.
CAUTION: When performing any service procedure
on a vehicle equipped with ABS, do not apply a
12-volt power source to the ground circuit of the
pump motor in the HCU. Doing this will damage the
pump motor and will require replacement of the
entire HCU.
CAUTION: An attempt to remove or disconnect cer-
tain system components may result in improper
system operation. Only those components with
approved removal and installation procedures in
this manual should be serviced.
RSBRAKES - ABS5-69
BRAKES - ABS (Continued)

CAUTION: If welding work is to be performed on the
vehicle, using an electric arc welder, the CAB con-
nector should be disconnected during the welding
operation.
CAUTION: Many components of the ABS System
are not serviceable and must be replaced as an
assembly. Do not disassemble any component
which is not designed to be serviced.
CAUTION: Only the recommended jacking or hoist-
ing positions for this vehicle are to be used when-
ever it is necessary to lift a vehicle. Failure to raise
a vehicle from the recommended locations could
result in lifting a vehicle by the hydraulic control
unit mounting bracket. Lifting a vehicle by the
hydraulic control unit mounting bracket will result
in damage to the mounting bracket and the hydrau-
lic control unit.
CAUTION: Brake fluid will damage painted surfaces.
If brake fluid is spilled on any painted surface,
wash off with water immediately.
STANDARD PROCEDURE - ANTILOCK BRAKE
SYSTEM BLEEDING
The base brake's hydraulic system must be bled
anytime air enters the hydraulic system. The ABS
though, particularly the ICU (HCU), should only be
bled when the HCU is replaced or removed from the
vehicle. The ABS must always be bled anytime it is
suspected that the HCU has ingested air. Under
most circumstances that require the bleeding of the
brakes hydraulic system, only the base brake
hydraulic system needs to be bled.
It is important to note that excessive air in the
brake system will cause a soft or spongy feeling
brake pedal.
During the brake bleeding procedure, be sure the
brake fluid level remains close to the FULL level in
the master cylinder fluid reservoir. Check the fluid
level periodically during the bleeding procedure and
add DOT 3 brake fluid as required.
The ABS must be bled as two independent braking
systems. The non-ABS portion of the brake systemwith ABS is to be bled the same as any non-ABS sys-
tem.
The ABS portion of the brake system must be bled
separately. Use the following procedure to properly
bleed the brake hydraulic system including the ABS.
BLEEDING
When bleeding the ABS system, the following
bleeding sequence must be followed to insure com-
plete and adequate bleeding.
(1) Make sure all hydraulic fluid lines are installed
and properly torqued.
(2) Connect the DRBIIItscan tool to the diagnos-
tics connector. The diagnostic connector is located
under the lower steering column cover to the left of
the steering column.
(3) Using the DRB, check to make sure the CAB
does not have any fault codes stored. If it does, clear
them using the DRB.
WARNING: WHEN BLEEDING THE BRAKE SYSTEM
WEAR SAFETY GLASSES. A CLEAR BLEED TUBE
MUST BE ATTACHED TO THE BLEEDER SCREWS
AND SUBMERGED IN A CLEAR CONTAINER FILLED
PART WAY WITH CLEAN BRAKE FLUID. DIRECT
THE FLOW OF BRAKE FLUID AWAY FROM YOUR-
SELF AND THE PAINTED SURFACES OF THE VEHI-
CLE. BRAKE FLUID AT HIGH PRESSURE MAY
COME OUT OF THE BLEEDER SCREWS WHEN
OPENED.
(4) Bleed the base brake system using the stan-
dard pressure or manual bleeding procedure. (Refer
to 5 - BRAKES - BASE - STANDARD PROCEDURE)
(5) Using the DRB, select ANTILOCK BRAKES,
followed by MISCELLANEOUS, then BLEED
BRAKES. Follow the instructions displayed. When
the scan tool displays TEST COMPLETED, discon-
nect the scan tool and proceed.
(6) Bleed the base brake system a second time.
Check brake fluid level in the reservoir periodically
to prevent emptying, causing air to enter the hydrau-
lic system.
(7) Fill the master cylinder reservoir to the full
level.
(8) Test drive the vehicle to be sure the brakes are
operating correctly and that the brake pedal does not
feel spongy.
5 - 70 BRAKES - ABSRS
BRAKES - ABS (Continued)

SPECIFICATIONS
SPECIFICATIONS - ABS FASTENER TORQUE
(Refer to 5 - BRAKES - BASE - SPECIFICA-
TIONS)
TONE WHEEL RUNOUT
DESCRIPTION SPECIFICATION
Front Tone Wheel
Maximum Runout0.15 mm (0.006 in.)
Rear Tone Wheel
Maximum Runout0.15 mm (0.006 in.)
WHEEL SPEED SENSOR AIR GAP
DESCRIPTION SPECIFICATION
Front Sensor0.35 ± 1.20 mm
0.014 ± 0.047 in.
Rear Sensor0.40 ± 1.20 mm
0.016 ± 0.047 in.
FRONT WHEEL SPEED
SENSOR
REMOVAL - WHEEL SPEED SENSOR (FRONT)
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
(2) Remove the tire and wheel assembly.
(3) Remove the sensor cable routing clamp screws.
CAUTION: When disconnecting the wheel speed
sensor from vehicle wiring harness, be careful not
to damage pins on connector
(4) Remove speed sensor cable grommets from
intermediate bracket on strut.
(5) Disconnect speed sensor cable from vehicle wir-
ing harness behind fender well shield.
(6) Remove the wheel speed sensor head mounting
bolt (Fig. 1).
(7) Remove sensor head from steering knuckle. If
sensor has seized due to corrosion,DO NOT USE
PLIERS ON SENSOR HEAD.Use a hammer and a
punch and tap edge of sensor ear, rocking the sensor
side-to-side until free.
(8) Remove front wheel speed sensor from vehicle.
INSTALLATION - WHEEL SPEED SENSOR
(FRONT)
CAUTION: Proper installation of wheel speed sen-
sor cables is critical to continued system operation.
Be sure that cables are installed in retainers. Fail-
ure to install cables in retainers as shown in this
section may result in contact with moving parts and
over extension of cables, resulting in an open cir-
cuit.
(1) Connect the front wheel speed sensor cable to
the vehicle wiring harness connector. Be sure speed
sensor cable connector is fully seated and locked into
vehicle wiring harness connector.
(2) Install the bolts attaching the routing clamps
to the body of the vehicle. Tighten the bolts to a
torque of 11 N´m (95 in. lbs.).
(3) Insert speed sensor cable grommets into inter-
mediate bracket on strut.
(4) Install the wheel speed sensor head mounting
bolt (Fig. 1). Tighten the bolt to a torque of 12 N´m
(105 in. lbs.)
(5) Install the wheel and tire assembly on vehicle.
(6) Lower vehicle.
(7) Road test vehicle to ensure proper operation of
the base and ABS brake systems.
Fig. 1 Front Wheel Speed Sensor Attaching Bolt
1 - MOUNTING BOLT
2 - WHEEL SPEED SENSOR
3 - DRIVESHAFT
4 - TONE WHEEL
5 - STEERING KNUCKLE
RSBRAKES - ABS5-71
BRAKES - ABS (Continued)

REAR WHEEL SPEED SENSOR
-AWD
REMOVAL - WHEEL SPEED SENSOR
(REAR-AWD)
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
CAUTION: When disconnecting speed sensor cable
from vehicle wiring harness be careful not to dam-
age pins on the electrical connectors. Also, inspect
connectors for any signs of previous damage.
(2) Remove grommet from floor pan of vehicle and
disconnect speed sensor cable connector from vehicle
wiring harness (Fig. 2).
CAUTION: When removing rear wheel speed sensor
cable from routing clips, be sure not to damage the
routing clips. Routing clips that are molded onto
the brake hose will require replacement of the brake
hose if damaged during removal or installation of
the speed sensor cable.
(3) Carefully remove speed sensor cable from
press-in routing clips along brake hose and tubing.
(4) Remove bolt securing wheel speed sensor cable
metal clip to rear of axle. Remove metal clip from
cable if necessary.
CAUTION: If speed sensor head has seized due to
corrosion, do not use pliers on speed sensor head
in an attempt to remove it. Use a hammer and apunch and tap mounting flange edge side-to-side,
rocking the sensor until free.
(5) Remove wheel speed sensor head attaching
bolt.
(6) Remove wheel speed sensor head from the axle,
and remove sensor from vehicle.
INSTALLATION - WHEEL SPEED SENSOR
(REAR-AWD)
CAUTION: Proper installation of wheel speed sen-
sor cables is critical to continued system operation.
Be sure that cables are installed in retainers. Fail-
ure to install cables in retainers as indicated may
result in contact with moving parts or over-exten-
sion of cables, resulting in an open circuit.
(1) Install wheel speed sensor head in axle flange.
CAUTION: Prior to installing the speed sensor head
attaching bolt, the plastic anti-rotation pin must be
fully seated into the bearing flange.
(2) Install wheel speed sensor head attaching bolt.
Tighten bolt to a torque 12 N´m (105 in. lbs.).
(3) Check the air gap between the face of the
wheel speed sensor and the top surface of the tone
wheel. (Refer to 5 - BRAKES - SPECIFICATIONS)
CAUTION: When installing wheel speed sensor
cable in the routing clips on rear brake flex hose,
be sure not to damage the routing clips. Routing
clips are molded onto the hose and will require
replacement of the brake hose if damaged.
(4) Install speed sensor cable under leaf spring
onto brake hose and tubing utilizing routing clips to
secure it in place.
(5) Install metal routing clip on speed sensor cable
and mount it to rear of axle with mounting bolt.
Tighten mounting bolt to 16 N´m (140 in. lbs.).
(6) Connect wheel speed sensor cable to vehicle
wiring harness (Fig. 2).Be sure speed sensor cable
connector is fully seated and locked into vehi-
cle wiring harness connector.
(7) Install speed sensor cable grommet into the
floor pan, being sure the grommet is fully seated into
the access hole.
(8) Lower vehicle.
(9) Road test vehicle to ensure proper operation of
the base and ABS braking systems.
Fig. 2 WHEEL SPEED SENSOR CONNECTOR
1 - CONNECTOR
2 - FLOOR PAN
3 - GROMMET
5 - 72 BRAKES - ABSRS

REAR WHEEL SPEED SENSOR
- FWD
REMOVAL - WHEEL SPEED SENSOR
(REAR-FWD)
(1) Raise vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE)
CAUTION: When disconnecting speed sensor cable
from vehicle wiring harness be careful not to dam-
age pins on the electrical connectors. Also, inspect
connectors for any signs of previous damage.
(2) Remove grommet from floor pan of vehicle and
disconnect speed sensor cable connector from vehicle
wiring harness (Fig. 3).
CAUTION: When removing rear wheel speed sensor
cable from routing clips, be sure not to damage the
routing clips. Routing clips that are molded onto
the brake hose will require replacement of the brake
hose if damaged during removal or installation of
the speed sensor cable.
(3) Carefully remove speed sensor cable from
press-in routing clips (Fig. 4).
(4) Remove bolt securing metal routing clip to rear
of axle and remove sensor cable from metal clip (Fig.
4).
(5) Remove secondary (yellow) retaining clip at
rear of wheel speed sensor head (Fig. 5).(6) Push up on metal retaining clip (Fig. 5) until it
bottoms. This will release wheel speed sensor head
from hub and bearing. While holding metal clip up,
pull back on wheel speed sensor head removing it
from hub and bearing.
(7) Remove wheel speed sensor assembly from
vehicle.
Fig. 3 WHEEL SPEED SENSOR CONNECTOR
1 - CONNECTOR
2 - FLOOR PAN
3 - GROMMET
Fig. 4 SPEED SENSOR CABLE ROUTING
1 - METAL CLIP AND MOUNTING BOLT
2 - ROUTING CLIPS
Fig. 5 SENSOR CONNECTION AT HUB AND
BEARING
1 - SECONDARY SENSOR RETAINING CLIP
2 - METAL SENSOR RETAINING CLIP
3 - HUB AND BEARING
RSBRAKES - ABS5-73

INSTALLATION - WHEEL SPEED SENSOR
(REAR-FWD)
CAUTION: Proper installation of wheel speed sen-
sor cable is critical to continued system operation.
Be sure that cable is installed in routing retainers/
clips. Failure to install cable in retainers may result
in contact with moving parts or over extension of
cable, resulting in an open circuit.
NOTE: Make sure wheel speed sensor stays clean
and dry as it is installed into the hub and bearing
cap.
(1) If metal sensor retaining clip is not in the neu-
tral installed position on hub and bearing cap, install
from the bottom, if necessary, and push clip upward
until it snaps into position.
(2) Install wheel speed sensor head into rear of
hub and bearing aligning index tab with the notch in
the top of the mounting hole. Push the sensor in
until it snaps into place on the metal retaining clip.
(3) Install secondary (yellow) retaining clip over
wheel speed sensor head and engage the tabs on each
side.
(4) Route sensor cable under leaf spring along rear
of axle. Install speed sensor cable into routing clips
on rear brake flex hose (Fig. 4).
(5) Install cable into metal routing clip and attach
it to the rear axle with mounting bolt (Fig. 4).
Tighten mounting bolt to 16 N´m (140 in. lbs.).
(6) Connect wheel speed sensor cable to vehicle
wiring harness (Fig. 3).Be sure speed sensor
cable connector is fully seated and locked into
vehicle wiring harness connector.
(7) Install speed sensor cable grommet into hole in
floor pan making sure grommet is fully seated into
hole.
(8) Lower vehicle.
(9) Road test vehicle to ensure proper operation of
the base and ABS braking systems.
TONE WHEEL
INSPECTION - TONE WHEEL
NOTE: Rear tone wheels for front-wheel-drive vehi-
cles are sealed within the hub and bearing assem-
bly and cannot be inspected or replaced.
Replacement of the hub and bearing is necessary.Tone wheels can cause erratic wheel speed sensor
signals. Inspect tone wheels for the following possible
causes.
²missing, chipped, or broken teeth
²contact with the wheel speed sensor
²wheel speed sensor to tone wheel alignment
²wheel speed sensor to tone wheel clearance
²excessive tone wheel runout
²tone wheel loose on its mounting surface
If a front tone wheel is found to need replacement,
the drive shaft must be replaced. No attempt should
be made to replace just the tone wheel. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/HALF SHAFT -
REMOVAL)
If a rear tone wheel is found to need replacement
on an all-wheel-drive model, the drive shaft must be
replaced. No attempt should be made to replace just
the tone wheel. (Refer to 3 - DIFFERENTIAL &
DRIVELINE/HALF SHAFT - REMOVAL)
If wheel speed sensor to tone wheel contact is evi-
dent, determine the cause and correct it before
replacing the wheel speed sensor or tone wheel.
Check the gap between the speed sensor head and
the tone wheel to ensure it is within specifications.
(Refer to 5 - BRAKES - ABS/ELECTRICAL - SPEC-
IFICATIONS)
Excessive wheel speed sensor runout can cause
erratic wheel speed sensor signals. Refer to SPECI-
FICATIONS in this section of the service manual for
the maximum allowed tone wheel runout (Refer to 5 -
BRAKES - ABS/ELECTRICAL - SPECIFICATIONS).
If tone wheel runout is excessive, determine if it is
caused by a defect in the driveshaft assembly or hub
and bearing. Replace as necessary.
Tone wheels are pressed onto their mounting sur-
faces and should not rotate independently from the
mounting surface. Replacement of the front drive-
shaft, rear driveshaft (AWD only) or rear hub and
bearing is necessary.
TRACTION CONTROL SWITCH
DIAGNOSIS AND TESTING - TRACTION
CONTROL SWITCH
(1) Remove lower column shroud.
(2) Disconnect traction control switch harness from
column harness below column.
(3) Using an ohmmeter, check for continuity read-
ing between pins. Refer to test table and (Fig. 6).
5 - 74 BRAKES - ABSRS
REAR WHEEL SPEED SENSOR - FWD (Continued)

TRACTION CONTROL SWITCH CONTINUITY
SWITCH POSITION CONTINUITY BETWEEN
ACTUATED PINS 1 AND 2
ILLUMINATION PINS 1 AND 3
ICU (INTEGRATED CONTROL
UNIT)
DESCRIPTION
The hydraulic control unit (HCU) and the control-
ler antilock brake (CAB) used with this antilock
brake system are combined (integrated) into one
unit, which is called the integrated control unit (ICU)
(Fig. 7). The ICU is located below the master cylinder
in the engine compartment (Fig. 8).
Two different ICU's (HCU and CAB) are used on
this vehicle depending on whether or not the vehicle
is equipped with traction control. The HCU on a
vehicle equipped with traction control has a valveblock that is approximately one inch longer than a
HCU on a vehicle that is equipped with ABS only.
The ABS-only ICU consists of the following compo-
nents: the CAB, eight (build/decay) solenoid valves
(four inlet valves and four outlet valves), valve block,
fluid accumulators, a pump, and an electric motor.
The ABS-with traction control ICU consists of the
following components: the CAB, eight (build/decay)
solenoid valves (four inlet valves and four outlet
valves), two traction control (ASR) valves, two
hydraulic shuttle valves, valve block, fluid accumula-
tors, a pump, and an electric motor.
The replaceable components of the ICU are the
HCU and the CAB. No attempt should be made to
service any individual components of the HCU or
CAB. For information on the CAB, (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/CONTROLLER ANTILOCK BRAKE -
DESCRIPTION).
OPERATION
For information of the ICU, refer to these individ-
ual components of the ICU:
²CONTROLLER ANTILOCK BRAKE (CAB)
(Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES/CONTROLLER ANTILOCK
BRAKE - OPERATION)
²HYDRAULIC CONTROL UNIT (HCU) (Refer to
5 - BRAKES - ABS/HYDRAULIC/MECHANICAL/
HCU (HYDRAULIC CONTROL UNIT) - OPERA-
TION)
For information on the ICU's hydraulic circuits,
refer to HYDRAULIC CIRCUITS AND VALVE
OPERATION. (Refer to 5 - BRAKES - ABS/HY-
DRAULIC/MECHANICAL - OPERATION)
Fig. 6 TRACTION CONTROL SWITCH CONNECTOR
Fig. 7 INTEGRATED CONTROL UNIT (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
Fig. 8 ICU LOCATION IN VEHICLE
1 - POWER BRAKE BOOSTER
2 - MASTER CYLINDER
3 - ICU
RSBRAKES - ABS5-75
TRACTION CONTROL SWITCH (Continued)