Back JEEP CHEROKEE 1995 Service Manual Online

BULB APPLICATIONÐYJ VEHICLES
GENERAL INFORMATION
The following Bulb Application Table lists the lamp
title on the left side of the column and trade number
or part number on the right.
CAUTION: Do not use bulbs that have a higher can-
dle power than the bulb listed in the Bulb Applica-
tion Table. Damage to lamp can result.
Do not touch halogen bulbs with fingers or other
oily surfaces. Bulb life will be reduced.
EXTERIOR LAMPSÐYJ
Back-up .................................................................1156
Center High Mounted Stoplamp ..........................912
Fog ............................................................................H3
Front Side Marker .................................................194
Headlamp/Sealed Beam....................................H6054
Park/Turn Signal..................................................3157
Tail/Stop ................................................................1157
INTERIOR LAMPSÐYJ
Service procedures for most of the lamps in the in-
strument panel, Instrument cluster and switches are
located in Group 8E, Instrument Panel and Gauges.
Some components have lamps that can only be ser-
viced by an Authorized Service Center (ASC) after
the component is removed from the vehicle. Contact
local dealer for location of nearest ASC.Dome/Cargo .........................................................212-2
Glove Compartment ...............................................194
Under Hood ............................................................105
Underpanel Courtesy...............................................89
INDICATOR LAMPS
Service procedures for most of the lamps in the in-
strument panel, instrument cluster and switches are
located in Group 8E, Instrument Panel and Gauges.
A/C Control ...............................................................74
Anti-lock Brake ........................................................74
Ash Receiver .........................................................1891
Brake Warning .........................................................74
Cigar Lighter ............................................................53
Fasten Seat Belts ....................................................74
Four Wheel Drive ....................................................74
Generator ................................................................194
Hazard.......................................................................74
Heater Control .......................................................194
High Beam..............................................................194
Illumination ............................................................194
Low Coolant..............................................................74
Radio ......................................................................ASC
Rocker Switch...........................................................74
Seat Belt ...................................................................74
Shift ...........................................................................74
Turn Signal.............................................................194
8L - 32 LAMPSÐYJ VEHICLESJ

RESTRAINT SYSTEMS
CONTENTS
page page
AIRBAG SYSTEM......................... 1
DIAGNOSIS............................. 2GENERAL INFORMATION.................. 1
SERVICE PROCEDURES................... 2
AIRBAG SYSTEM
WARNING: THIS AIRBAG SYSTEM IS A SENSITIVE,
COMPLEX MECHANICAL UNIT. BEFORE ATTEMPT-
ING TO REMOVE OR INSTALL THE AIRBAG SYS-
TEM OR RELATED STEERING WHEEL AND
STEERING COLUMN COMPONENTS YOU MUST
FIRST DISARM THE AIRBAG FIRING MECHANISM.
FAILURE TO DO SO COULD RESULT IN ACCIDEN-
TAL DEPLOYMENT AND POSSIBLE PERSONAL IN-
JURY.
WARNING: THE AIRBAG MODULE INFLATOR/SEN-
SOR ASSEMBLY CONTAINS SODIUM AZIDE AND
POTASSIUM NITRATE. THESE MATERIALS ARE
POISONOUS AND EXTREMELY FLAMMABLE. CON-
TACT WITH ACID, WATER OR HEAVY METALS MAY
PRODUCE HARMFUL AND IRRITATING GASES (SO-
DIUM HYDROXIDE IS FORMED IN THE PRESENCE
OF MOISTURE) OR COMBUSTIBLE COMPOUNDS.
DO NOT ATTEMPT TO DISMANTLE THE MODULE
OR TAMPER WITH ITS ARMING LEVER. DO NOT
PUNCTURE, INCINERATE, OR BRING INTO CON-
TACT WITH ELECTRICITY. DO NOT STORE AT TEM-
PERATURES EXCEEDING 200ÉF.WARNING: REPLACE AIRBAG SYSTEM COMPO-
NENTS WITH PARTS SPECIFIED IN THE CHRYSLER
MOPAR PARTS CATALOG ONLY. IT IS OF PARTICU-
LAR IMPORTANCE THAT ANY COMPONENTS USED
IN THIS MECHANICALLY-FIRED AIRBAG SYSTEM
NOT BE MIXED WITH COMPONENTS FROM AN
ELECTRICALLY-FIRED AIRBAG SYSTEM. SUBSTI-
TUTE PARTS MAY APPEAR THE SAME, BUT INTER-
NAL DIFFERENCES MAY RESULT IN INFERIOR
OCCUPANT PROTECTION.
WARNING: THE FASTENERS, SCREWS, AND
BOLTS, ORIGINALLY USED FOR THE AIRBAG COM-
PONENTS, HAVE SPECIAL COATINGS AND ARE
SPECIFICALLY DESIGNED FOR THE AIRBAG SYS-
TEM. THEY MUST NEVER BE REPLACED WITH ANY
SUBSTITUTES. ANYTIME A NEW FASTENER IS
NEEDED, REPLACE WITH THE CORRECT FASTEN-
ERS PROVIDED IN THE SERVICE PACKAGE OR
SPECIFIED IN THE CHRYSLER MOPAR PARTS CAT-
ALOG.
GENERAL INFORMATION
The airbag system is a standard equipment safety
device on XJ (Cherokee) models. It is designed to pro-
tect the driver from serious injury, caused by a fron-
tal impact of the vehicle. If the airbag module
assembly is defective and non-deployed, refer to
Chrysler Corporation current return list for proper
handling procedures.
Following are general descriptions of the major
components in the airbag system.AIRBAG MODULE
The airbag module protective cover is the only vis-
ible part of the system. The module is mounted di-
rectly to the steering wheel. Under the airbag
module cover, the airbag cushion and its supporting
components are contained. The airbag module con-
tains a housing to which the cushion and impact sen-
sor/inflator assembly are attached and sealed. The
airbag module is non-serviceable, and must be re-
placed if deployed or damaged in any way.
The impact sensor/inflator assembly is mounted to
the back of the module. The inflator seals the hole in
JRESTRAINT SYSTEMS 8M - 1

the airbag cushion so it can discharge the gas it pro-
duces directly into the cushion. The protective cover
is fitted to the front of the airbag module and forms
a decorative cover in the center of the steering wheel.
Upon airbag deployment, this cover will split hori-
zontally.
STORAGE
The airbag module must be stored in its original,
special container until used for service. Also, it must
be stored in a clean, dry environment; away from
sources of extreme heat, sparks, and high electrical
energy. Always place or store the module on a surface
with the trim cover facing up to minimize movement
in case of accidental deployment.
IMPACT SENSOR/INFLATOR ASSEMBLY
The impact sensor/inflator assembly is mounted to
the back of the airbag module. It seals the hole in
the steering wheel side of the airbag cushion so that
gas produced in the inflator can be discharged di-
rectly into the cushion.
The impact sensor provides verification of the di-
rection and severity of the impact. A spherical sens-
ing mass housed in a cylinder will move forward and
rotate a D-shaft when the vehicle is subjected to a
frontal impact of sufficient severity. Airbag inflation
is designed to occur at a precisely calibrated vehicle
deceleration force, and is not linked to vehicle road
speed.The D-shaft retains two spring-loaded firing pins.
When a firing pin is released by the D-shaft, it
strikes and ignites a primer. The primer then reacts
with the pelletized, solid generant contained in the
inflator to produce the nitrogen gas that inflates the
airbag cushion.
ARMING/DISARMING MECHANISM
The steering wheel hub incorporates an airbag
arming/disarming mechanism and a specially de-
signed nut-blocker. The nut-blocker serves as a safety
to prevent removal of the airbag module until the
unit has been disarmed. A removable plastic cover
plug on the top, outer hub of the steering wheel al-
lows access to the arming screw.
When the airbag module is disarmed, the arming
screw extends upward from the steering wheel hub.
This will prevent installation of the plastic cover
plug. Also, the nut-blocker is retracted to allow ac-
cess to the two upper airbag module mounting nuts.
When the airbag module is armed, the plastic cover
plug will install flush with the outer surface of the
steering wheel hub. In addition, the nut-blocker will
prevent access to the two upper airbag module
mounting nuts.
DIAGNOSIS
This mechanical airbag system can not be diag-
nosed or repaired. The only serviced component is
the airbag module assembly. If the airbag module isdamaged in any way or deployed, it must be re-
placed.
SERVICE PROCEDURES
AIRBAG SYSTEM SERVICE (DEPLOYED)
Any vehicle which is to be returned to use after an
airbag deployment, must have the airbag module re-
placed. This is a one-time component and cannot be
reused.
AIRBAG MODULE HANDLING
UNDEPLOYED
At no time should any source of electricity be per-
mitted near the inflator on the back of the module.
When carrying an undeployed module, the trim cover
should be pointed away from the body to minimizeinjury in the event of accidental deployment. If the
module is placed on a bench or other surface, the
plastic trim cover should be face up to minimize
movement in case of accidental deployment.
In addition, the airbag module should be disarmed
whenever the steering wheel or steering column re-
quires service or removal. Failure to observe this
warning could result in accidental airbag deployment
and possible personal injury. Refer to Group 19 -
Steering for more service procedures on steering
wheel and steering column.
8M - 2 RESTRAINT SYSTEMSJ

DEPLOYED
Following an airbag deployment, the vehicle inte-
rior will contain a powdery residue. This residue is
primarily sodium bicarbonate (baking soda), used as
an airbag cushion lubricant. However, there will also
be traces of sodium hydroxide powder, a chemical
byproduct of the generant used for airbag deploy-
ment. Since this powder can irritate the skin, eyes,
nose or throat, be sure to wear safety glasses, rubber
gloves and a long-sleeved shirt during cleanup (Fig.
1).
If you experience skin irritation during
cleanup, run cool water over the affected area.
Also, if you experience irritation of the nose or
throat, exit the vehicle for fresh air until the ir-
ritation ceases. If irritation continues, see a
physician.
CLEANUP PROCEDURE
Remove the airbag and airbag module from the ve-
hicle. Use a vacuum cleaner to remove any residual
powder from the vehicle interior. Clean from outside
the vehicle and work your way inside, so that you
avoid kneeling or sitting on an uncleaned area.
Be sure to vacuum the heater and A/C outlets as
well (Fig. 2). Run the blower on low and vacuum any
powder expelled from the plenum. You may need to
vacuum the interior of the car a second time to re-
cover all of the powder.
Place the deployed airbag and module in your ve-
hicular scrap pile.
AIRBAG MODULE REMOVE/INSTALL
WARNING: THIS AIRBAG SYSTEM IS A SENSITIVE,
COMPLEX MECHANICAL UNIT. BEFORE ATTEMPT-ING TO REMOVE OR INSTALL THE AIRBAG SYS-
TEM OR RELATED STEERING WHEEL AND
STEERING COLUMN COMPONENTS YOU MUST
FIRST DISARM THE AIRBAG FIRING MECHANISM.
FAILURE TO DO SO COULD RESULT IN ACCIDEN-
TAL DEPLOYMENT AND POSSIBLE PERSONAL IN-
JURY.
When removing a deployed airbag module,
rubber gloves, eye protection and long-sleeved
shirt should be worn. There may be deposits on
the airbag module and other interior surfaces,
which can cause irritation to the skin and eyes
in large doses.
(1) Disconnect battery negative cable and isolate.
(2) Using a small screwdriver, remove plastic cover
plug from top outer surface of steering wheel hub.
Exit vehicle and disarm airbag by reaching through
driver's side window and turning arming screw
counter-clockwise to its travel limit. When the screw
has reached its travel limit it will extend 1 inch
above the outer surface of the steering wheel hub
cover. This is done using an 8mm socket and manual
drive. DO NOT USE POWER-DRIVEN TOOLS.
(3) From back side of steering wheel, remove 4
nuts attaching airbag module to steering wheel (Fig.
3). This is done using a 10mm socket and manual
drive. DO NOT USE POWER-DRIVEN TOOLS.
(4) Remove airbag module from steering wheel.
(5) Reverse removal procedures to install. Tighten
airbag module attaching nuts to 9 to 11 Nzm (80 to
100 in. lbs.). Exit vehicle and arm airbag by reaching
through driver's side window and turning arming
screw clockwise to its travel limit. Arming screw
torque should not exceed 1.1 to 1.7 Nzm (10-15 in.
lbs.). Reinstall plastic cover plug in steering wheel
hub.
Fig. 1 Wear Safety Glasses and Rubber Gloves
Fig. 2 Vacuum Heater and A/C Outlets
JRESTRAINT SYSTEMS 8M - 3

(9) Allow epoxy to cure 24 hours at room tempera-
ture or use heat gun with a 260É-371ÉC (500É-700ÉF)
range for 15 minutes. Hold gun approximately
254mm (10 inches) from repaired area.
(10) After conductive epoxy is properly cured re-
move wedge or clamp from terminal or pigtail and
check operation of rear window defogger. Do not at-
tach connectors until curing is complete.
DEFOGGER SWITCH REMOVE/INSTALL
XJ MODELS
(1) Remove the instrument cluster bezel. Refer to
Group 8E - Instrument Panel and Gauges for proce-
dure.
(2) Remove the switch housing panel.
(3) Unplug the switch connector. Slightly depress
the switch mounting tabs and remove the switch.
(4) Reverse removal procedures to install.
YJ MODELS
(1) Remove 6 bezel screws (Fig. 3).
(2) Slide bezel toward the steering wheel.
(3) Remove 3 screws (Fig. 4).
(4) Unplug the connector from the defogger switch.
(5) Squeeze the ends of the switch to release the
plastic retaining fingers and push outward.
(6) Reverse removal procedures to install.
DEFOGGER RELAY/TIMER REMOVE/INSTALL
XJ MODELS
The rear defogger relay is in the relay center. The
relay center is located on the lower instrument panel
trim cover just right of the steering column.
(1) Remove the rear defogger relay (red) from the
relay center (Fig. 5).
(2) Reverse removal procedures to install.
YJ MODELS
The rear defogger relay is located behind the park-
ing brake pedal in the left cowl side area. Unplug re-
lay from connector and replace with new relay. Be
certain that relay is taped back into place on harness
with plastic cover facing up and terminals facing
down.
Fig. 3 Instrument Bezel Remove/InstallÐYJ
Fig. 4 Defogger Switch Remove/InstallÐYJ
Fig. 5 Rear Defogger RelayÐXJ
8N - 4 REAR WINDOW DEFOGGERJ

POWER LOCK MOTOR
(1) Once it is determined which lock motor is inop-
erative, that motor can be tested. Disconnect the wire
connector at the motor. Apply 12 volts to the motor
terminals to check its operation in one direction. Re-
verse the polarity to check the operation in the other
direction. If OK, repair circuits to power lock/unlock
relays as required. If not OK, replace the motor.
(2) If all lock motors are inoperative, the problem
may be caused by one shorted motor. Disconnecting a
shorted motor will allow the good motors to operate.
Disconnect each motor connector, one at a time, and
re-check both lock and unlock functions while operat-
ing the door lock switch. If disconnecting one motor
causes the other motors to become functional, go
back to step 1 to test the disconnected motor.
KEYLESS ENTRY TRANSMITTER
(1) Depress either transmitter button and note
whether red Light-Emitting Diode (LED) on trans-
mitter case lights. If OK, go to next step. If not OK,
replace batteries as described under Keyless Entry
Transmitter in Service Procedures. Test transmitter
operation. If OK, discard faulty batteries. If not OK,
go to next step.
(2) Perform transmitter program procedure with
suspect transmitter and another known good trans-
mitter, as described in Service Procedures. Test oper-
ation with both transmitters. If both transmitters fail
to operate power locks, see Keyless Entry Module di-
agnosis. If known good transmitter operates power
locks and suspect transmitter does not, replace faulty
transmitter. Be certain to perform transmitter pro-
gram procedure again when replacing faulty trans-
mitter and to erase test transmitter access code from
keyless entry module.
KEYLESS ENTRY MODULE
(1) Check fuse 9 in fuseblock module. If OK, go to
next step. If not OK, replace fuse.
(2) Check for battery voltage at fuse 9. If OK, go to
next step. If not OK, repair circuit from power distri-
bution center.
(3) Access keyless entry module connectors as de-
scribed in Keyless Entry Module Remove/Install.
(4) Unplug module connector from module. Check
connector and receptacle in module for loose, cor-
roded, or damaged terminals and pins. If OK, go to
next step. If not OK, repair as required.
(5) Probe connector cavity for module terminal 1
and check for battery voltage. If OK, go to next step.
If not OK, repair circuit to fuse 9 as required.
(6) Install a jumper wire from connector cavity for
module terminal 1 to connector cavity for module ter-
minal 3. Doors should lock. If OK, go to step 8. If not
OK, go to next step.
(7) Check for continuity between connector cavity
for module terminal 3 and lock relay terminal 3 (86).
There should be continuity. If OK, replace lock relay.
If not OK, repair circuit as required.
(8) Install a jumper wire from connector cavity for
module terminal 1 to connector cavity for module ter-
minal 4. Doors should unlock. If OK, replace module.
If not OK, go to next step.
(9) Check for continuity between connector cavity
for module terminal 4 and unlock relay terminal 3
(86). There should be continuity. If OK, replace un-
lock relay. If not OK, repair circuit as required.
JPOWER LOCKS 8P - 7

SERVICE PROCEDURES
KEYLESS ENTRY TRANSMITTER
To replace transmitter batteries, separate transmit-
ter case by prying gently with a trim stick or other
wide flat-bladed tool at center seam (Fig. 2). Case
snaps open and shut. Replace with CR1616 3-volt
batteries or equivalent (Fig. 3).
TRANSMITTER PROGRAMMING PROCEDURE
(1) Open the driver's door of the vehicle. Leave it
open through the programming procedure.
(2) Move the mechanical door lock lever to the
LOCK position.
(3) Turn the ignition switch to the ON position.
(4) Within 20 seconds, aim a transmitter at the
keyless entry module receiver dome and press the
LOCK button for at least 5 seconds. Once the module
accepts the programming code, the driver's door will
unlock.
(5) Once the first transmitter has been pro-
grammed, additional transmitters (up to 4) may beprogrammed into the module. Within 20 seconds of
the previous transmitter programming, move the me-
chanical door lock lever to the LOCK position. Aim
another transmitter at the receiver dome and press
the LOCK button for at least 5 seconds. The door
lock will cycle again.
(6) To lock the programmed codes into the module,
the ignition switch must be turned OFF and back
ON within 20 seconds after programming the last
transmitter's code. At that time, all previous codes
are erased from the module.
POWER LOCK SWITCH REMOVE/INSTALL
(1) Remove the interior door latch release assem-
bly and control panel retaining screws (Fig. 4).
(2) Disconnect the control linkage and the wire
harness connector.
(3) Remove the latch release and control panel as-
sembly.
(4) The switch is retained to the panel with clips
(Fig. 5). Push in on the retainer part of the clip and
pry the clips.
(5) To install switch, position switch and press in
retainer clips until they snap into position. Reverse
remaining removal procedures to complete installa-
tion.
POWER LOCK MOTOR REMOVE/INSTALL
DOORS
(1) Remove interior door latch release assembly
and control panel retaining screws (Fig. 4).
(2) Disconnect control linkage and wire harness
connector.
(3) Remove latch release and control panel assem-
bly.
Fig. 2 Separate Transmitter Halves
Fig. 3 Battery Install
Fig. 4 Power Window/Lock Control Panel Remove/
Install
8P - 8 POWER LOCKSJ

(14) Repeat steps 8 through 13 for each wire.
(15) Re-tape the wire harness starting 1-1/2 inches
behind the connector and 2 inches past the repair.
(16) Re-connect the repaired connector.
(17) Connect the battery, and test all affected sys-
tems.
TERMINAL REPLACEMENT
(1) Disconnect battery.
(2) Disconnect the connector being repaired from
its mating half.
(3) Remove connector locking wedge, if required
(Fig. 14).
(4) Position the connector locking finger away from
the terminal using the proper pick from special tool
kit 6680. Pull on the wire to remove the terminal
from the connector (Figs. 15 and 16).
(5) Cut the wire 6 inches from the back of the
connector.
(6) Remove 1 inch of insulation from the wire on
the harness side.
(7) Select a wire from the terminal repair assembly
that best matches the color wire being repaired.
(8) Cut the repair wire to the proper length and
remove 1 inch of insulation.
(9) Place a piece of heat shrink tubing over one side
of the wire. Make sure the tubing will be long enough
to cover and seal the entire repair area.
(10) Spread the strands of the wire apart on each
part of the exposed wires (Fig. 11 example 1).
(11) Push the two ends of wire together until the
strands of wire are close to the insulation (Fig. 11
example 2).
(12) Twist the wires together (Fig. 11 example 3).(13) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(14) Center the heat shrink tubing over the joint
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing.
(15) Insert the repaired wire into the connector.
(16) Install the connector locking wedge, if re-
quired, and reconnect the connector to its mating
half/component.
(17) Re-tape the wire harness starting 1-1/2 inches
behind the connector and 2 inches past the repair.
(18) Connect the battery, and test all affected sys-
tems.
DIODE REPLACEMENT
(1) Disconnect the battery.
(2) Locate the diode in the harness, and remove the
protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 18).
(4) Remove the insulation from the wires in the
harness. Only remove enough insulation to solder in
the new diode.
(5) Install the new diode in the harness, making
sure current flow is correct. If necessary, refer to the
appropriate wiring diagram for current flow.
(6) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(7) Tape the diode to the harness using electrical
tape. Make sure the diode is completely sealed from
the elements.
(8) Re-connect the battery, and test affected sys-
tems.Fig. 17 Stagger Cutting Wires (Typical)
Fig. 18 Diode Identification
8W - 8 WIRING DIAGRAMSÐGENERAL INFORMATIONJ

Circuit T17 from fuse 3 in the power distribution
center supplies voltage to the coil and contact sides
of the TCC relay. When the PCM provides a ground
path on circuit K54 for the coil side of the relay, the
relay contacts close.
When the relay contacts close, they connect circuit
T17 with circuit T22. Circuit T22 supplies battery
voltage to the case grounded TCC solenoid. Circuit
K54 connects to PCM cavity 54.
HELPFUL INFORMATION
²In the RUN or START position, the ignition switch
connects circuit A1 from fuse 4 in the PDC to circuit
A21.
UPSHIFT LAMP
On vehicles equipped with a manual transmission,
the PCM grounds the up-shift lamp on circuit K54.
Circuit K54 connects to cavity 54 of the PCM.
POWER STEERING PRESSURE SWITCH
The PCM supplies voltage to the power steering
pressure switch on circuit K10. Circuit Z12 provides
ground for the switch. When the switch closes, volt-
age flows through the switch to ground on circuit
Z12. The switch closes during periods of high power
steering pump load and low engine speed; such as
parking maneuvers.
Circuit K10 connects to cavity 10 of the PCM. Cir-
cuit Z12 terminates at the right rear of the engine.
TACHOMETER SIGNAL
The PCM supplies the signal for the tachometer on
circuit G21. Circuit G21 connects to cavity 43 of the
PCM.
MALFUNCTION INDICATOR LAMP (MIL)
The PCM provides ground for the instrument clus-
ter malfunction indicator lamp on circuit G3. The
MIL displays the message CHECK ENGINE when il-
luminated. Circuit F87 provides voltage for the lamp.
DATA LINK CONNECTOR
Circuit F12 supplies battery voltage to the data
link connector. Circuit F12 originates at fuse 11 in
the Power Distribution Center.
Circuit D20 connects to cavity 45 of the PCM. Cir-
cuit D20 is the SCI receive circuit for the PCM.
Circuit D21 connects to cavity 25 of the PCM. Cir-
cuit D21 is the SCI transmit circuit for the PCM.
Circuit Z11 provides ground for the data link con-
nector. Circuit Z11 terminates at the right rear of the
engine. Circuit Z11 also connects to cavity 5 of the
PCM.
HELPFUL INFORMATION
²Circuit Z1 also supplies a ground for the PCM
high current drivers.
²If the system loses ground for the Z11 circuits at
the right rear of the engine, the vehicle will not op-
erate. Check the connection at the ganged-ground cir-
cuit eyelet.
²Circuit F12 splices to supply battery voltage to the
vehicle speed control switch, back-up lamp switch,
A/C compressor clutch relay, windshield washer fluid
level sensor and radiator fan relay (4.0L engines).
BRAKE SWITCH INPUT
Circuit K29 provides the brake switch input to the
PCM. Circuit V40 connects to cavity 29 of the PCM.
POWER (DEVICE) GROUND
Circuit Z12 connects to cavities 11 and 12 of the
PCM. The Z12 circuit provides ground for PCM inter-
nal drivers that operate high current devices like the
injectors and ignition coil.
Internal to the PCM, the power (device) ground cir-
cuit connects to the PCM sensor return circuit (from
circuit K4).
HELPFUL INFORMATION
²The grounding point for circuit Z12 is the right
rear of the engine.
²If the system loses ground for the Z12 circuits at
the rear of the engine, the vehicle will not operate.
Check the connection at the ganged-ground circuit
eyelet.
²On vehicles equipped with the 4.0L engine and au-
tomatic transmission, circuit Z12 splices to provide
ground for the transmission control module.
EXTENDED IDLE SWITCH
On Police Package vehicles, an optional extended
idle switch provides an input to the Powertrain Con-
trol Module (PCM) on circuit K10. Circuit K10 con-
nects to cavity 10 of the PCM. Circuit F60 supplies
battery voltage to the extended idle switch. Circuit
Z1 grounds the switch.
CCD BUS
On vehicles equipped with the 4.0L engine, circuits
D1 and D2 connect the Powertrain Control Module
(PCM) to the CCD Bus. Circuit D1 connects to cavity
26 of the PCM. Circuit D2 connects to cavity 46 of
the PCM. Circuits D1 and D2 are a twisted pair of
wires.
J8W-30 FUEL/IGNITIONÐXJ VEHICLES 8W - 30 - 5

TRANSMISSION CONTROLS
UPSHIFT LAMP
On vehicles equipped with a manual transmission,
the PCM grounds the up-shift lamp on circuit K54.
Circuit K54 connects to cavity 54 of the PCM.
FOUR-WHEEL DRIVE (4WD) SWITCH
When the 4WD switch closes, circuit Z1 provides
ground for the 4WD indicator lamp in the instrument
cluster. Circuit F87 connects to the instrument clus-
ter and supplies battery voltage to the 4WD indicator
lamp. Circuit 107 connects the indicator lamp to the
4WD switch. Circuit 106 connects the lamp to the in-
strument cluster and circuit F87.
TRANSMISSION CONTROL MODULEÐ4.0L
ENGINE ONLY
Vehicles equipped with the 4.0L engine have elec-
tronically controlled solenoids in the automatic trans-
mission valve body.
The Transmission Control Module (TCM) receives
inputs from the Throttle Position Sensor (TPS) on
circuit K22 and the stop lamp switch on circuit K29.
Circuit K4 connects to the TCM to provide ground for
the TPS signal. The TCM receives the transmission
output speed sensor signal on circuit T505. Circuit
A14 from fuse 2 in the Power Distribution Center
supplies battery voltage to the TCM. Circuit Z12 pro-
vides ground for the TCM.
The TCM powers the S1 solenoid on circuit T510,
the S2 solenoid on circuit T509, and the S3 solenoid
on circuit T508. Circuit Z12 provides ground for the
S1, S2, and S3 solenoids.
TORQUE CONVERTER CLUTCH (TCC) SOLENOID
AND RELAYÐ2.5L ENGINE ONLY
The TCC solenoid is only used on 2.5L engines
with the three-speed automatic transmissions. The
Powertrain Control Module (PCM) operates the TCC
solenoid by energizing the TCC relay.
Circuit T17 from fuse 12 in the Power Distribution
Center (PDC) supplies voltage to the coil and contact
sides of the TCC relay. When the PCM provides a
ground path on circuit K54 for the coil side of the re-
lay, the relay contacts close.
When the relay contacts close, they connect circuit
T17 with circuit T22. Circuit T22 supplies battery
voltage to the case grounded TCC solenoid. Circuit
K54 connects to PCM cavity 54.
HELPFUL INFORMATION
²In the RUN or START position, the ignition switch
connects circuit A1 from fuse 6 in the PDC to circuit
A21.
DIAGRAM INDEX
Component Page
4-WD Indicator Lamp......................8W-31-4
4-WD Indicator Switch.....................8W-31-4
Back-Up Lamp Switch.....................8W-31-3
Fuse 2 (PDC)...........................8W-31-4
Fuse 6 (PDC).........................8W-31-2, 3
Fuse 11 (PDC)..........................8W-31-3
Fuse 12 (PDC)..........................8W-31-2
Ignition Switch........................8W-31-2, 3
Powertrain Control Module..................8W-31-2
Park/Neutral Position Switch.................8W-31-3
TCC Relay.............................8W-31-2
TCC Solenoid...........................8W-31-2
Transmission Control Module.................8W-31-2
J8W-31 TRANSMISSION CONTROLSÐXJ VEHICLES 8W - 31 - 1