Brakes JEEP GRAND CHEROKEE 2002 WJ / 2.G Repair Manual

INSTALLATION
(1) Insert the sensor through the backing plate
(Fig. 9).
(2) Apply Mopar Lock N' Seal or Loctite 242tto
the original sensor bolt. Use a new bolt if the original
is worn or damaged.
(3) Tighten the sensor bolt to 12-14 N´m (106-124
in. lbs.).
(4) Secure the sensor wire in the brackets and the
retainers on the rear brake lines. Verify that the sen-
sor wire is secure and clear of the rotating compo-
nents.
(5) Route the sensor wires to the rear seat area.
(6) Feed the sensor wires the through floorpan
access hole and seat the sensor grommets into the
floorpan.
(7) Remove the support and lower the vehicle.(8) Fold the rear seat and carpet forward for
access to the sensor wires and connectors.
(9) Connect the sensor wires to the harness con-
nectors.
(10) Reposition the carpet and fold the rear seat
down.
HCU (HYDRAULIC CONTROL
UNIT)
DESCRIPTION
The HCU consists of a valve body, pump motor,
and wire harness.
OPERATION
Accumulators in the valve body store extra fluid
released to the system for ABS mode operation. The
pump is used to clear the accumulator of brake fluid
and is operated by a DC type motor. The motor is
controlled by the CAB.
The valves modulate brake pressure during
antilock braking and are controlled by the CAB.
The HCU provides three channel pressure control
to the front and rear brakes. One channel controls
the rear wheel brakes in tandem. The two remaining
channels control the front wheel brakes individually.
During antilock braking, the solenoid valves are
opened and closed as needed. The valves are not
static. They are cycled rapidly and continuously to
modulate pressure and control wheel slip and decel-
eration.
During normal braking, the HCU solenoid valves
and pump are not activated. The master cylinder and
power booster operate the same as a vehicle without
an ABS brake system.
During antilock braking, solenoid valve pressure
modulation occurs in three stages, pressure increase,
pressure hold, and pressure decrease. The valves are
all contained in the valve body portion of the HCU.
PRESSURE DECREASE
The outlet valve is opened and the inlet valve is
closed during the pressure decrease cycle.
A pressure decrease cycle is initiated when speed
sensor signals indicate high wheel slip at one or
more wheels. At this point, the CAB closes the inlet
then opens the outlet valve, which also opens the
return circuit to the accumulators. Fluid pressure is
allowed to bleed off (decrease) as needed to prevent
wheel lock.
Once the period of high wheel slip has ended, the
CAB closes the outlet valve and begins a pressure
increase or hold cycle as needed.
Fig. 8 Sensor Mounting Bolt
1 - WHEEL SPEED SENSOR
2 - MOUNTING BOLT
Fig. 9 Wheel Speed Sensor
1 - WHEEL SPEED SENSOR
2 - BACKING PLATE
5 - 46 BRAKES - ABSWJ
REAR WHEEL SPEED SENSOR (Continued)

PRESSURE HOLD
Both solenoid valves are closed in the pressure
hold cycle. Fluid apply pressure in the control chan-
nel is maintained at a constant rate. The CAB main-
tains the hold cycle until sensor inputs indicate a
pressure change is necessary.
PRESSURE INCREASE
The inlet valve is open and the outlet valve is
closed during the pressure increase cycle. The pres-
sure increase cycle is used to counteract unequal
wheel speeds. This cycle controls re-application of
fluid apply pressure due to changing road surfaces or
wheel speed.
REMOVAL
(1) Remove the negative battery cable from the
battery.
(2) Remove the air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - REMOVAL).
(3) Pull the CAB harness connector release up and
remove connector (Fig. 10).(4) Remove the brake lines from the HCU.
(5) Remove the HCU/CAB side mounting bolt and
the two rear mounting bolts. (Fig. 11).
(6) Remove the HCU/CAB assembly from the vehi-
cle.
INSTALLATION
(1) Install HCU/CAB assembly into the mounting
bracket and tighten mounting bolts to 12 N´m (9 ft.
lbs.).
(2) Install the brake lines to the HCU and tighten
to 16 N´m (12 ft. lbs.).
(3) Install CAB harness connector and push down
connector release.
(4) Install air cleaner housing,(Refer to 9 -
ENGINE/AIR INTAKE SYSTEM/AIR CLEANER
HOUSING - INSTALLATION).
(5) Install negative battery cable to the battery.
(6) Bleed base and ABS brake systems,(Refer to 5 -
BRAKES - STANDARD PROCEDURE) OR (Refer to
5 - BRAKES - STANDARD PROCEDURE).
Fig. 10 CAB Connector Release
1 - CONNECTOR RELEASE
2 - CAB
Fig. 11 HCU/CAB Assembly
1 - SIDE MOUNTING BOLT
2 - REAR MOUNTING BOLTS
WJBRAKES - ABS 5 - 47
HCU (HYDRAULIC CONTROL UNIT) (Continued)

²SLIGHT TAIL WIND AT IDLE
²SLOW TRAFFIC
²TRAFFIC JAMS
²HIGH SPEED
²STEEP GRADES
Driving techniques that avoid overheating are:
²Idle with A/C off when temperature gauge is at
end of normal range.
²Increase engine speed for more air flow is recom-
mended.(1) TRAILER TOWING:
Consult Trailer Towing section of owners manual.
Do not exceed limits.
(2) AIR CONDITIONING; ADD-ON OR AFTER
MARKET:
A maximum cooling package should have been
ordered with vehicle if add-on or after market A/C is
installed. If not, maximum cooling system compo-
nents should be installed for model involved per
manufacturer's specifications.
(3) RECENT SERVICE OR ACCIDENT REPAIR:
Determine if any recent service has been per-
formed on vehicle that may effect cooling system.
This may be:
²Engine adjustments (incorrect timing)
²Slipping engine accessory drive belt(s)
²Brakes (possibly dragging)
²Changed parts. Incorrect water pump, or pump
rotating in wrong direction due to belt not correctly
routed
²Reconditioned radiator or cooling system refill-
ing (possibly under filled or air trapped in system).
NOTE: If investigation reveals none of the previous
items as a cause for an engine overheating com-
plaint, refer to following Cooling System Diagnosis
charts.
These charts are to be used as a quick-reference
only. Refer to the group text for information.
Fig. 4 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
7 - 4 COOLINGWJ
COOLING (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
6. Poor seals at the radiator cap. 6. (a) Check condition of cap and cap seals.
(Refer to 7 - COOLING/ENGINE/RADIATOR
PRESSURE CAP - DIAGNOSIS AND
TESTING).
(b) Check condition of radiator filler
neck. If neck is bent or damaged,
replace radiator.
7. Coolant level low in radiator but
not in coolant reserve/overflow tank.
This means the radiator is not
drawing coolant from the coolant
reserve/overflow tank as the engine
cools7. (a) Check condition of radiator cap and
cap seals. (Refer to 7 - COOLING/ENGINE/
RADIATOR PRESSURE CAP - DIAGNOSIS
AND TESTING).
(b) Check condition of radiator filler neck. If
neck is bent or damaged, replace radiator.
(c) Check condition of the hose from the
radiator to the coolant tank. It should fit tight
at both ends without any kinks or tears.
Replace hose if necessary.
(d) Check coolant reserve/overflow tank and
tanks hoses for blockage. Repair as
necessary.
8. Incorrect coolant concentration 8. Check coolant. (Refer to 7 - COOLING/
ENGINE/COOLANT - DESCRIPTION) for
correct coolant/water mixture ratio.
9. Coolant not flowing through
system9. Check for coolant flow at radiator filler
neck with some coolant removed, engine
warm and thermostat open. Coolant should
be observed flowing through radiator. If flow
is not observed, determine area of
obstruction and repair as necessary.
10. Radiator or A/C condenser fins
are dirty or clogged.10. Remove insects and debris. (Refer to 7 -
COOLING/ENGINE/RADIATOR -
CLEANING).
11. Radiator core is corroded or
plugged.11. Have radiator re-cored or replaced.
12. Aftermarket A/C installed without
proper radiator.12. Install proper radiator.
13. Fuel or ignition system
problems.13. Refer to FUEL and /or IGNITION
CONTROL for diagnosis.
14. Dragging brakes. 14. Check and correct as necessary. (Refer
to 5 - BRAKES - DIAGNOSIS AND
TESTING) for correct procedures.
15. Bug screen or cardboard is
being used, reducing airflow.15. Remove bug screen or cardboard.
16. Thermostat partially or
completely shut.16. Check thermostat operation and replaces
necessary. (Refer to 7 - COOLING/ENGINE/
ENGINE COOLANT THERMOSTAT -
DIAGNOSIS AND TESTING).
7 - 6 COOLINGWJ
COOLING (Continued)

(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Enter secured access mode by entering the
vehicle four-digit PIN.
(5) Select ENTER to update PCM VIN.
NOTE: If three attempts are made to enter secure
access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To
exit this lockout mode, turn the ignition switch to
the ON position for one hour, then enter the correct
PIN. (Ensure all accessories are turned off. Also
monitor the battery state and connect a battery
charger if necessary).
(6) Press ENTER to transfer the secret key (the
SKIM will send the secret key to the PCM).
(7) Press Page Back to get to the Select System
menu and select ENGINE, MISCELLANEOUS, and
SRI MEMORY CHECK.
(8) The DRBIIItwill ask, ªIs odometer reading
between XX and XX?º Select the YES or NO button
on the DRBIIIt. If NO is selected, the DRBIIItwill
read, ªEnter Odometer Reading (From I.P. odome-
ter)º. Enter the odometer reading from the instru-
ment cluster and press ENTER.
PROGRAMMING THE SKIM
(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Program the vehicle four-digit PIN into SKIM.
(5) Select COUNTRY CODE and enter the correct
country.
NOTE: Be sure to enter the correct country code. If
the incorrect country code is programmed into
SKIM, it cannot be changed and the SKIM must be
replaced.
(6) Select YES to update VIN (the SKIM will learn
the VIN from the PCM).
(7) Press ENTER to transfer the secret key (the
PCM will send the secret key to the SKIM).
(8) Program ignition keys to the SKIM.
NOTE: If the PCM and the SKIM are replaced at the
same time, all vehicle ignition keys will need to be
replaced and programmed to the new SKIM.
PROGRAMMING IGNITION KEYS TO THE SKIM
(1) Turn the ignition switch to the On position
(transmission in Park/Neutral).
(2) Use the DRBIIItand select THEFT ALARM,
SKIM, then MISCELLANEOUS.
(3) Select PROGRAM IGNITION KEY'S.
(4) Enter secured access mode by entering the
vehicle four-digit PIN.
NOTE: A maximum of eight keys can be learned to
each SKIM. Once a key is learned to a SKIM it (the
key) cannot be transferred to another vehicle.
(5) Obtain ignition keys to be programmed from
the customer (8 keys maximum).
(6) Using the DRBIIIt, erase all ignition keys by
selecting MISCELLANEOUS, and ERASE ALL CUR-
RENT IGN. KEYS.
(7) Program all of the ignition keys.
If ignition key programming is unsuccessful, the
DRBIIItwill display one of the following messages:
²Programming Not Attempted- The DRBIIIt
attempts to read the programmed key status and
there are no keys programmed into SKIM memory.
²Programming Key Failed (Possible Used
Key From Wrong Vehicle)- SKIM is unable to pro-
gram an ignition key transponder due to one of the
following:
²The ignition key transponder is faulty.
²The ignition key transponder is or has been
already programmed to another vehicle.
²8 Keys Already Learned, Programming Not
Done- The SKIM transponder ID memory is full.
²Learned Key In Ignition- The ID for the igni-
tion key transponder currently in the ignition lock
cylinder is already programmed in SKIM memory.
ADJUSTABLE PEDALS
MODULE
REMOVAL
(1) Disconnect the negative battery cable.
(2) Remove the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL - REMOV-
AL).
(3) Remove the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - REMOVAL).
(4) Remove the adjustable pedal motor for accessi-
bility. (Refer to 5 - BRAKES/HYDRAULIC/MECHAN-
ICAL/PEDAL - REMOVAL).
(5) Remove the two mounting clips from the mod-
ule (Fig. 1).
(6) Disconnect the electrical connector.
(7) Remove the adjustable pedal module.
8E - 2 ELECTRONIC CONTROL MODULESWJ
ELECTRONIC CONTROL MODULES (Continued)

INSTALLATION
(1) Install the module on the mounting pins in the
vehicle.
(2) Reconnect the electrical connector.
(3) Install the two mounting clips for the module
(Fig. 1).
(4) Install the adjustable pedal motor. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/PEDAL -
INSTALLATION).
(5) Install the steering column opening cover
(Refer to 23 - BODY/INSTRUMENT PANEL/STEER-
ING COLUMN OPENING COVER - INSTALLA-
TION).
(6) Install the cluster bezel (Refer to 23 - BODY/
INSTRUMENT PANEL/CLUSTER BEZEL -
INSTALLATION).
(7) Reconnect the negative battery cable.
BODY CONTROL MODULE
DESCRIPTION
A Body Control Module (BCM) is concealed below
the driver side end of the instrument panel (Fig. 2).
The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehiclethrough both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus. The
electronic functions and features that the BCM sup-
ports or controls include the following:
The BCM for this model is serviced only as a com-
plete unit. Many of the electronic features in the
vehicle controlled or supported by the BCM are pro-
grammable using either the Electronic Vehicle Infor-
mation Center (EVIC) user interface, or the DRBIIIt
scan tool. In addition, the BCM software is Flash
compatible, which means it can be reprogrammed
using Flash reprogramming procedures. A BCM can
only be repaired by or replaced through an autho-
rized electronic warranty repair station. Refer to the
latest version of the Warranty Policies and Proce-
dures manual for a current listing of authorized elec-
tronic repair stations.OPERATION
The Body Control Module (BCM) is designed to
control and integrate many of the electronic features
and functions of the vehicle. The microprocessor-
based BCM hardware and software monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other electronic modules in
the vehicle through its communication over the PCI
data bus network. The internal programming of the
BCM microprocessor allows the BCM to determine
the tasks it needs to perform and their priorities. The
Fig. 1 ADJUSTABLE PEDALS MODULE
1 - ELECTRICAL CONNECTOR
2 - MODULE MOUNTING BRACKET
3 - BRAKE BOOSTER
4 - ADJUSTABLE PEDALS MOUNTING BRACKET
5 - ADJUSTABLE PEDALS CONTROL MODULE
6 - HOLD DOWN CLIPS
Fig. 2 Body Control Module
1 - JUNCTION BLOCK
2 - SCREWS (4)
3 - BODY CONTROL MODULE
4 - FUSE COVER LOCATOR CHANNELS
5 - FUSE COVER MOUNTING SLOTS
6 - INSTRUMENT PANEL WIRE HARNESS CONNECTORS
WJELECTRONIC CONTROL MODULES 8E - 3
ADJUSTABLE PEDALS MODULE (Continued)

(5) Connect the two instrument panel wire harness
connectors to the BCM.
(6) Reinstall the instrument panel fuse cover to
the bottom of the BCM and JB unit. (Refer to 8 -
ELECTRICAL/POWER DISTRIBUTION/FUSE
COVER - INSTALLATION).
(7) Connect the battery negative cable.
COMMUNICATION
DESCRIPTION
The Programmable Communication Interface (PCI)
data bus system is a single wire multiplex system
used for vehicle communications. Multiplexing is a
system that enables the transmission of several mes-
sages over a single channel or circuit.
Many of the control modules in a vehicle require
information from the same sensing device. Multiplex-
ing reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
A multiplex system allows the information flowing
between controllers to be monitored using a diagnos-
tic scan tool. This system allows a control module to
broadcast message data out onto the bus where all
other control modules can read the messages that are
being sent. When a module reads a message on the
data bus that it requires, it relays that message to
its microprocessor. Each module ignores the mes-
sages on the data bus that it dosen't recognize.
OPERATION
Data exchange between modules is achieved by
serial transmission of encoded data over a single wire
broadcast network. The PCI data bus messages are
carried over the bus in the form of Variable Pulse
Width Modulated (VPWM) signals. The PCI data bus
speed is an average 10.4 Kilo-bits per second (Kbps).
The voltage network used to transmit messages
requires biasing and termination. Each module on
the PCI data bus system provides its own biasing
and termination. Each module (also referred to as a
node) terminates the bus through a terminating
resistor and a terminating capacitor. The Powertrain
Control Module (PCM) is the only dominant node for
the PCI data bus system.
The PCI bus uses low and high voltage levels to
generate signals. The voltage on the buss varies
between zero and seven and one-half volts. The lowand high voltage levels are generated by means of
variable-pulse width modulation to form signals of
varying length.
When a module is transmitting on the bus, it is
reading the bus at the same time to ensure message
integrity.
Each module is capable of transmitting and receiv-
ing data simultaneously.
The PCI data bus can be monitored using the
DRBIIItscan tool. It is possible for the bus to pass
all DRBIIIttests and still be faulty if the voltage
parameters are all within the specified range and
false messages are being sent.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The Controler Antilock Brake (CAB) is mounted to
the Hydraulic Control Unit (HCU) and operates the
ABS system (Fig. 4).
OPERATION
The CAB voltage is supplied by the ignition switch
in the RUN position. The CAB contains dual micro-
processors. A logic block in each microprocessor
receives identical sensor signals. These signals are
processed and compared simultaneously. The CAB
contains a self check program that illuminates the
ABS warning light when a system fault is detected.
Faults are stored in a diagnostic program memory
and are accessible with the DRBIIItscan tool. ABS
faults remain in memory until cleared, or until after
the vehicle is started approximately 50 times. Stored
Fig. 4 Controller Antilock Brakes
1 - HCU
2 - MOTOR
3 - CAB
8E - 6 ELECTRONIC CONTROL MODULESWJ
BODY CONTROL MODULE (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - TCM QUICK LEARN
The quick learn procedure requires the use of the
DRBIIItscan tool.
This program allows the electronic transmission
system to recalibrate itself. This will provide the
proper transmission operation. The quick learn pro-
cedure should be performed if any of the following
procedures are performed:
²Transmission Assembly Replacement
²Transmission Control Module Replacement
²Solenoid Pack Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or ReconditionTo perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay in PARK until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRBt
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
8E - 22 ELECTRONIC CONTROL MODULESWJ
TRANSMISSION CONTROL MODULE (Continued)

For further diagnosis of the brake indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). The park
brake switch input to the instrument cluster can be
diagnosed using conventional diagnostic tools and
methods. For proper diagnosis of the brake fluid level
switch input to the CAB, the anti-lock brake system,
the CAB, the PCI data bus, or the electronic message
inputs to the instrument cluster that control the
brake indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
DIAGNOSIS AND TESTING - BRAKE INDICATOR
The diagnosis found here addresses an inoperative
park brake indicator condition. If there are problems
with several indicators in the instrument cluster,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). If the brake
indicator stays on with the ignition switch in the On
position and the park brake released, or comes on
while driving, (Refer to 5 - BRAKES - DIAGNOSIS
AND TESTING). If no brake system problem is
found, the following procedures will help to locate a
shorted or open circuit, or a faulty park brake switch
input. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, details
of wire harness routing and retention, connector pin-
out information and location views for the various
wire harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SIDE CURTAIN AIRBAG,
FRONT IMPACT SENSOR, SIDE IMPACT SENSOR,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
INDICATOR ILLUMINATES DURING BULB TEST, BUT DOES
NOT WHEN PARK BRAKE APPLIED
(1) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the park brake switch from the switch
terminal. Apply the parking brake. Check for conti-nuity between the park brake switch terminal and a
good ground. There should be continuity. If OK, go to
Step 2. If not OK, replace the faulty park brake
switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the red brake warning indicator driver circuit cavi-
ties of the instrument panel wire harness connector
for the park brake switch and the instrument panel
wire harness connector for the instrument cluster.
There should be continuity. If not OK, repair the
open red brake warning indicator driver circuit
between the park brake switch and the instrument
cluster as required.
INDICATOR REMAINS ILLUMINATED - BRAKE SYSTEM
CHECKS OK
(1) Disconnect and isolate the battery negative
cable. Disconnect the instrument panel wire harness
connector for the park brake switch from the park
brake switch terminal. Check for continuity between
the terminal of the park brake switch and a good
ground. There should be no continuity with the park
brake released, and continuity with the park brake
applied. If OK, go to Step 2. If not OK, replace the
faulty park brake switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the red brake warning indicator driver circuit cavity
of the instrument panel wire harness connector for
the park brake switch and a good ground. There
should be no continuity. If not OK, repair the shorted
red brake warning indicator driver circuit between
the park brake switch and the instrument cluster as
required.
CHECK GAUGES INDICATOR
DESCRIPTION
A check gauges indicator is standard equipment on
all instrument clusters. The check gauges indicator is
located on the right edge of the instrument cluster, to
the right of the speedometer. The check gauges indi-
cator consists of the words ªCHECK GAGESº
imprinted on a red lens. The lens is located behind a
cutout in the opaque layer of the instrument cluster
overlay. The dark outer layer of the overlay prevents
the indicator from being clearly visible when it is not
illuminated. The ªCHECK GAGESº text appears sil-
houetted against a red field through the translucent
outer layer of the overlay when the indicator is illu-
minated from behind by a Light Emitting Diode
(LED), which is soldered onto the instrument cluster
electronic circuit board. The check gauges indicator
8J - 16 INSTRUMENT CLUSTERWJ
BRAKE/PARK BRAKE INDICATOR (Continued)

SPEED CONTROL
TABLE OF CONTENTS
page page
SPEED CONTROL
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - ROAD TEST.....2
SPECIFICATIONS
TORQUE - SPEED CONTROL.............3
CABLE
DESCRIPTION..........................3
OPERATION............................3
REMOVAL
REMOVAL - 4.0L.......................3
REMOVAL - 4.7L.......................3
INSTALLATION
INSTALLATION - 4.0L...................4
INSTALLATION - 4.7L...................4
SERVO
DESCRIPTION..........................5OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................6
SWITCH
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................7
INSTALLATION..........................7
VACUUM RESERVOIR
DESCRIPTION..........................8
OPERATION............................8
DIAGNOSIS AND TESTING - VACUUM
RESERVOIR..........................8
REMOVAL.............................8
INSTALLATION..........................9
SPEED CONTROL
DESCRIPTION
The speed control system is electronically con-
trolled and vacuum operated. Electronic control of
the speed control system is integrated into the Pow-
ertrain Control Module (PCM). The controls consist
of two steering wheel mounted switches. The
switches are labeled: ON/OFF, RES/ACCEL, SET,
COAST, and CANCEL.
The system is designed to operate at speeds above
30 mph (50 km/h).
WARNING: THE USE OF SPEED CONTROL IS NOT
RECOMMENDED WHEN DRIVING CONDITIONS DO
NOT PERMIT MAINTAINING A CONSTANT SPEED,
SUCH AS IN HEAVY TRAFFIC OR ON ROADS THAT
ARE WINDING, ICY, SNOW COVERED, OR SLIP-
PERY.
OPERATION
When speed control is selected by depressing the
ON switch, the PCM allows a set speed to be stored
in PCM RAM for speed control. To store a set speed,
depress the SET switch while the vehicle is moving
at a speed between 35 and 85 mph. In order for the
speed control to engage, the brakes cannot be
applied, nor can the gear selector be indicating the
transmission is in Park or Neutral.
The speed control can be disengaged manually by:
²Stepping on the brake pedal
²Depressing the OFF switch
²Depressing the CANCEL switch.
²Depressing the clutch pedal (if equipped).
NOTE: Depressing the OFF switch or turning off the
ignition switch will erase the set speed stored in
the PCM.
For added safety, the speed control system is pro-
grammed to disengage for any of the following condi-
tions:
²An indication of Park or Neutral
²A rapid increase rpm (indicates that the clutch
has been disengaged)
²Excessive engine rpm (indicates that the trans-
mission may be in a low gear)
²The speed signal increases at a rate of 10 mph
per second (indicates that the coefficient of friction
between the road surface and tires is extremely low)
WJSPEED CONTROL 8P - 1