(2) Note any indication of drum/rotor overheating,
wheel dragging or the vehicle pulling to one side
when the brakes are applied.
(3) Evaluate any performance complaints received
from the owner/operator.
(4) Repair the brake system as necessary. Refer to
Group, 5 Brakes for additional information and ser-
vice procedures.
TIRES
RECOMMENDED MAINTENANCE
The general condition of the tires and the inflation
pressures should be inspected at the same time the
engine oil is changed and the oil filter is replaced.
In addition, the tires/wheels should be rotated at
the intervals described in the Maintenance Schedules
section of this group.
INSPECTION
Inspect the tires for excessive wear, damage, etc.
Test the tires for the recommended inflation pres-sure. Refer to the tire inflation pressure decal located
on the inside of the glove box door, and also to Group
22, Tires And Wheels.
ROTATION
Refer to Group 22, Tires And Wheels for the recom-
mended method of tire/wheel rotation for a Jeep ve-
hicle.
BODY COMPONENTS
LUBRICATION REQUIREMENTS
All Jeep operating mechanisms and linkages
should be lubricated when necessary. The door
weatherstrip seals should be lubricated to prolong
their life as well as to improve door sealing.
LUBRICANT SPECIFICATIONS
All applicable exterior and interior vehicle operat-
ing mechanisms should be:
²Inspected
²Cleaned
²Pivot/sliding contact areas on the mechanisms
should then be lubricated.
Multi-purpose NLGI GC-LB MOPAR Multi-Mileage
Lubricant or an equivalent, should be used to lubri-
cate the mechanisms. The door weatherstrip seals
should be lubricated with silicone lubricant spray.
Refer to the Body Lubricant Specifications chart be-
low for additional lubricant applications.
LUBRICATION
All pivoting and sliding contact areas, should be lu-
bricated periodically to ensure quiet, easy operation
and to protect against wear and corrosion. Areas in-
clude:
²Seat tracks.
²Door hinges/latches/strikers.
²Liftgate/tailgate/hood hinges (Fig. 11).
(1) As required, lubricate the body components
with the specified lubricants.
(2) Apply silicone lubricant to a cloth and wipe it
on door seals to avoid over-spray that can soil pas-
senger clothing.
(3) Before applying lubricant, the component
should be wiped clean. After lubrication, any excess
lubricant should be removed.
(4) The door lock cylinders should be lubricated 2
times each year (preferably autumn and spring):
²Spray a small amount of lock cylinder lubricant di-
rectly into the lock cylinder.
²Apply a small amount to the key and insert it into
the lock cylinder.
²Rotate it to the locked position and then back to
the unlocked position several times.
²Remove the key. Wipe the lubricant from it with a
clean cloth to avoid soiling of clothing.
Fig. 9 Park Brake Equalizer (XJ)ÐTypical
Fig. 10 Park Brake Equalizer (YJ)ÐTypical
0 - 32 LUBRICATION AND MAINTENANCEJ
MASTER CYLINDER/POWER BRAKE BOOSTER
A 25 mm bore master cylinder and 205 mm (8.07
in.) dual diaphragm power brake booster are used for
all ABS applications (Fig. 2).
The master cylinder has a removable plastic reser-
voir which is the only serviceable component. The
cylinder body and pistons are not repairable and are
serviced as an assembly. The check valve and grom-
met are the only serviceable parts on the booster.
The booster itself is only serviced as an assembly.
COMBINATION VALVE
A combination valve is used with the ABS system
(Fig. 2). The valve contains a front/rear brake pres-
sure differential switch and rear brake proportioning
valve. The combination valve is connected between
the master cylinder and HCU.
The pressure differential switch is connected to the
red brake warning light. The switch is actuated by
movement of the switch valve. The switch monitors
fluid pressure in the separate front/rear brake hy-
draulic circuits.
A decrease or loss of fluid pressure in either hy-
draulic circuit will cause the switch valve to shuttle
forward or rearward in response to the pressure dif-
ferential. Movement of the switch valve will push the
switch plunger upward. This closes the switch inter-
nal contacts completing the electrical circuit to the
red warning light. The switch valve remains in an
actuated position until the fault is repaired.
The rear proportioning valve is used to balance front-
rear brake action.
ELECTRONIC CONTROL UNIT (ECU)
A separate electronic control unit (ECU) operates
the ABS system (Fig. 3). The ECU is separate from
other vehicle electrical circuits. ECU voltage source
is through the ignition switch in the Run position.The ECU is located under the instrument panel in
the passenger compartment. On YJ models, it is just
above the heater plenum in line with the glove box.
In left hand drive XJ models, it at the right side of
the steering column. In right hand drive models, it is
near the cowl panel
The ECU contains dual microprocessors. A logic
block in each microprocessor receives identical sensor
signals. These signals are processed and compared si-
multaneously.
The ECU contains a self check program that illu-
minates the ABS warning light when a system fault
is detected. Faults are stored in a diagnostic program
memory and are accessible with the DRB scan tool.
ABS faults remain in memory until cleared, or un-
til after the vehicle is started approximately 50
times. Stored faults arenoterased if the battery is
disconnected.
WHEEL SPEED SENSORS
A speed sensor is used at each wheel. The sensors
convert wheel speed into an electrical signal. This
signal is transmitted to the antilock ECU.
A gear type tone ring serves as the trigger mecha-
nism for each sensor. The tone rings are mounted at
the outboard ends of the front and rear axle shafts.
Different sensors are used at the front and rear
wheels (Fig. 4). The front/rear sensors have the same
electrical values but are not interchangeable.
Fig. 2 ABS Master Cylinder-Booster-Combination
Valve-HCU
Fig. 3 Antilock ECU
5 - 34 ABS OPERATION AND SERVICEJ
(2) Align and attach harness connector to ECU.
Slide connector into engagement with tangs on ECU.
Then tilt connector downward and into engagement
with ECU pin terminals. Exercise care as pin termi-
nals can be damaged if connector is forced into place.
(3) Connect harness to security alarm module, if
equipped.
(4) Position ECU bracket under instrument panel.
(5) Install and tighten ECU mounting bracket
bolts/nuts to 8-14 Nzm (75- 125 in. lbs.) torque.
(6) Install trim panel on instrument panel, if re-
moved.
ECU REMOVAL/INSTALLATION (YJ MODELS)
The antilock ECU is attached to the dash panel in-
side the passenger compartment. It is positioned just
above the heater/air conditioning plenum housing, in
line with the glove box (Fig. 16).
The ECU is attached to the dash panel by bolts
and nuts that are accessible from the engine com-
partment. The fasteners are located just to the right
of the battery.
On models with air conditioning, it will be neces-
sary to remove the air conditioning fascia panel and
ducts for access to the ECU and harness connecter.
HCU REMOVAL (XJ)
A new design HCU is used in 1995 models. The
new HCU has built-in accumulators that store the
extra fluid released for antilock mode operation. As a
result, the master cylinder and HCU are no longer
interconnected by hoses.The 1995 and prior hy-
draulic control units are NOT interchangeable.
(1) Disconnect vent hoses at air cleaner cover.
(2) Loosen clamp securing air cleaner hose to in-
take manifold. Use screwdriver to tap clamp loose.
(3) Remove air cleaner cover and hose. Then re-
move air filter from air cleaner shell (Fig. 17).
(4) Remove two bolts and one nut that secure air
cleaner housing to body panel (Fig. 17).
(5) Remove air cleaner housing from engine com-
partment.
Fig. 16 ECU Location (YJ)
Fig. 17 Air Cleaner Components
JABS OPERATION AND SERVICE 5 - 41
(3) Reach under the instrument panel and depress
the switch shaft release/retainer button (Fig. 14).
Pull the switch control knob and shaft outward.
(4) Remove the headlamp switch retaining nut
from the front of the instrument panel (Fig. 15).(5) Disconnect the wire harness connector from the
switch.
(6) Remove the headlamp switch from the instru-
ment panel.
(7) Reverse removal procedures to install.
INSTRUMENT PANEL REMOVE/INSTALL
(1) Disconnect battery negative cable.
(2) Remove the following (Fig. 16):
²parking brake release handle
²lower heat/AC duct below steering column
²ash receiver
²lower instrument panel
²cluster bezel
²cluster assembly
²radio
²climate control panel
²instrument panel switches
²headlamp switch
²antenna connector
²blower motor resistors
²ground lead
²unplug glove box lamp
²defroster cowl outlet panel
Remove driver's side heat/AC outlet to gain
access to driver's side defroster cowl outlet
panel retaining clip to aid in removal (Fig. 17).
²instrument panel attaching bolts
²steering column attaching bolts
²instrument panel assembly.
The instrument panel wiring harness is at-
tached to the back of the instrument panel as-
sembly and must be installed correctly.
(3) To install instrument panel, position instru-
ment panel assembly on side mounting bolts (Fig.
18).
(4) Route wiring harnesses and secure instrument
panel assembly mounting points.
(5) Connect tube to lap cooler.
(6) Reverse removal procedures to complete instal-
lation.
Fig. 13 Printed Circuit And Cluster Connector
Fig. 14 Headlamp Switch Knob And Shaft Remove/
Install
Fig. 15 Headlamp Switch Remove/Install
8E - 20 INSTRUMENT PANEL AND GAUGESÐXJJ
RADIO ILLUMINATION RELAY
If the relay fails any one of Relay Tests, it is faulty
and should be replaced. If the relay passes the Relay
Tests, proceed to the Relay Circuit Tests.
On XJ models, the radio illumination relay is lo-
cated in the relay center (Fig. 2), which is fastened to
the lower instrument panel reinforcement behind the
lower instrument panel near the steering column. On
YJ models, the relay is taped to the instrument panel
wiring harness above and to the right of the radio,
near the glove box.
RELAY TESTS
Remove relay to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30.(2) Resistance value between terminals 85 and 86
(electromagnet) is 7565 ohms.
(3) Connect a battery to terminals 85 and 86. There
should now be continuity between terminals 30 and 87,
and no continuity between terminals 87A and 30.
RELAY CIRCUIT TESTS
With relay still removed, perform the following
tests:
(1) The common feed terminal (30) is connected to
the radio display feed circuit. There should be conti-
nuity between cavity for relay terminal 30 and clock/
radio display feed cavity of radio connector at all
times. If not, repair circuit as required.
(2) The normally closed terminal (87A) is connected
to terminal 30 in the de-energized position. This circuit
provides ignition-switched battery voltage to the radio
display when the headlamp switch is off. There should
be battery voltage present at cavity for relay terminal
87A with the ignition switch in the ON position. If not,
repair circuit to ignition switch as required.
(3) The normally open terminal (87) is connected to
terminal 30 in the energized position. This circuit
provides instrument panel dimmer controlled feed to
the radio display when the headlamp switch is on.
There should be voltage present at cavity for relay
terminal 87 when the headlamp switch is on. Also,
the voltage reading should vary as the panel dimmer
switch is rotated. If not, repair circuit or panel dim-
mer switch as required.
(4) The coil battery terminal (86) connected to the
electromagnet in the relay. Check as follows:
(a) On YJ models, it is energized when the head-
lamp switch is on. There should be battery voltage at
cavity for relay terminal 86 with the headlamp switch
on. If not, repair circuit to headlamp switch as re-
quired.
(b) On XJ models, it is grounded at all times.
There should be continuity to ground at cavity for
relay terminal 86 at all times. If not, repair circuit
to ground as required.
RADIO CONNECTIONS
Fig. 2 Radio Illumination Relay - XJ
RADIO ILLUMINATION RELAY CONNECTIONS
8F - 4 AUDIO SYSTEMSJ
INTERIOR LAMPS
INDEX
page page
Dome Lamp ReplacementÐXJ............... 17
Dome/Courtesy Lamp Service InformationÐXJ . . . 16
Dome/Courtesy Lamp Trouble DiagnosisÐXJ.... 16Lighted Vanity Mirror Trouble DiagnosisÐXJ..... 16
Lighted Vanity MirrorÐXJ................... 16
Overhead ConsoleÐXJ..................... 17
DOME/COURTESY LAMP SERVICE
INFORMATIONÐXJ
Voltage is applied at all times via the dome lamp
fuse to each of the interior lamp bulbs. The interior
lamp bulbs illuminate when they are connected to
body ground via the switch:
²Headlamp switch.
²Glove box switch.
²Door pillar switch.
²Liftgate switch (if the cargo lamp is ON).
If equipped with Security Alarm Module, refer to
Group 8Q, Vehicle Theft Security System.
DOME/COURTESY LAMP TROUBLE DIAGNOSISÐ
XJ
ALL LAMPS INOPERATIVE
(1) Rotate the headlamp switch rheostat clockwise.
The lamps should light. If not OK, remove, inspect
and test the dome lamp fuse. Replace if bad.
(2) If the fuse is OK, repair the open circuit in the
wire harness to vehicle body ground.
ONE LAMP INOPERATIVE
(1) Measure the resistance across the bulb holder
terminals. The ohmmeter should indicate zero ohms.
If not, replace the bulb.
(2) Measure the voltage between the voltage side
of the bulb holder and vehicle body ground. The volt-
meter should indicate battery voltage. If not, repair
the open circuit in the wire harness to the splice.
LAMPS INOPERATIVE WITH ONE OR MORE
DOORS OPENED
(1) Remove the inoperative switch from the door
pillar and connect the switch wire directly to ground.
The lamp should light.
(2) If not, check for an open circuit in black
(ground) wire. Repair as necessary. If lamps still do
not light, replace the switch.
LIGHTED VANITY MIRRORÐXJ
SERVICE INFORMATION
Both the driver and the front passenger sunvisor
can be equipped with a lighted vanity mirror. A lamplocated at each side of the vanity mirror. The lamps
are switched ON automatically when the mirror
cover is lifted (Fig. 1).
Voltage is applied directly to the vanity lamp bulbs
via the dome lamp fuse.
LIGHTED VANITY MIRROR TROUBLE
DIAGNOSISÐXJ
VANITY LAMPS INOPERATIVE
(1) Remove, inspect and test the dome lamp fuse.
Replace if defective.
(2) Test the dome lamp operation. If OK, go to the
next step. If not OK, repair the open circuit in the
wire harness from the splice.
(3) Measure the voltage between the pink wire on
the switch connector and vehicle body ground. The
voltmeter should indicate battery voltage. If not OK,
repair the open circuit in the wire harness from the
splice.
(4) Connect a jumper wire from the ground side of
the switch to a good vehicle body ground. Measure
the resistance to vehicle body ground. The ohmmeter
should indicate zero ohms. If not, repair the open cir-
cuit in the wire harness to vehicle body ground.
Fig. 1 Lighted Vanity Mirror
8L - 16 LAMPSÐXJ VEHICLESJ
INTERIOR LIGHTING
INDEX
page page
Cargo Lamp, Courtesy Lamps and Dome Lamp.... 1
Chime/Buzzer Module....................... 2
Diagram Index............................ 2
General Information........................ 1
Glove Box Lamp........................... 1
Ignition Switch Lamp........................ 1Instrument Panel Illumination Lamps............ 1
Reading Lamps........................... 2
Time Delay Relay.......................... 1
Underhood Lamp.......................... 2
Visor Vanity Mirror Lamps.................... 2
GENERAL INFORMATION
Circuit M1 supplies power to the glove box lamp,
left courtesy lamp, right courtesy lamp, dome lamp,
and cargo lamp. The M1 circuit also connects to the
remote keyless entry module. Circuit M1 is protected
by the ignition off draw (IOD) fuse (fuse 9) in the fuse
block.
Circuit E2 supplies power for the instrument panel
illumination lamps.
INSTRUMENT PANEL ILLUMINATION LAMPS
Circuit E2 from the headlamp switch splices to
supply power to the following illumination lamps:
²Ash receiver lamp
²Cigar lighter lamp
²Transmission range indicator lamp
²Transfer case range indicator lamp
²A/C-Heater switch lamp
²Heated rear window lamp
²Rear wiper switch lamp
²Fog lamp switch lamp
Fuse 19 in the fuse block protects circuit E2. Circuit
Z1 provides ground for all of the illumination lamps
except for the cigar lighter lamp. The cigar lighter
lamp is case grounded.
HELPFUL INFORMATION
Circuit E2 also supplies power to the radio, LCD
relay and the illumination lamps in the instrument
cluster.
IGNITION SWITCH LAMP
The time delay relay is used to allow a time-ON
function for the ignition switch lamp and the courtesy
lamp. Power for the relay is received on the M1
circuit from the IOD fuse (fuse F9) in the fuse block.
Circuit M2 provides ground for the time delay relay
through the right and left door ajar switches and the
headlamp switch. When a door is opened, or the
headlamp switch is moved to the dome lamp position,a ground path is provided for the relay on circuit M2.
This energizes the relay, causing the contacts to close.
When the relay contacts close, power is provided
through the relay to circuit M50. The M50 circuit
supplies current to the ignition switch lamp. Circuit
Z1 provides ground for the lamp.
GLOVE BOX LAMP
Circuit M1 from the IOD fuse (fuse F9) in the fuse
block powers the glove box lamp. A case grounded
switch, in series after the lamp, closes when the glove
box door is opened. The switch completes a path to
ground on circuit Z1.
CARGO LAMP, COURTESY LAMPS AND DOME
LAMP
Circuit M1 from the IOD fuse (fuse F9) in the fuse
block supplies power to the cargo, courtesy lamps and
dome lamp. This circuit is HOT at all times. The
ground path for the lamp is provided in three differ-
ent ways.
One way is through the door jamb switches. Circuit
M2 connects to the door jamb switches from the cour-
tesy and dome lamps. The switches are connected to
ground circuit Z1. When a door is opened, the plunger
in the switch closes, completing a path to ground.
The second way is through the liftgate switch. Cir-
cuit M2 connects to circuit M4 at the cargo lamp.
Circuit M4 connects to the liftgate switch. The lift-
gate switch connects to ground circuit Z1. When the
lift gate opens, the plunger in the switch closes, com-
pleting a path to ground.
The third ground path is through the headlamp
switch. Circuit M2 is spliced in with the headlamp
switch. When the operator turns the headlamp switch
to the dome lamp ON position, a ground path is
provided through the switch.
J8W-44 INTERIOR LIGHTINGÐXJ VEHICLES 8W - 44 - 1
READING LAMPS
Circuit M1 from the IOD fuse (fuse F9) in the fuse
block supplies power to the reading lamps. Circuit
M1 is HOT at all times. When the operator depresses
the reading lamp, the reading lamp switch closes and
supplies ground on circuit Z1.
VISOR VANITY MIRROR LAMPS
Circuit M1 from the IOD fuse (fuse F9) in the fuse
block supplies power to the vanity lamps. Circuit M1
is HOT at all times. When the vanity lamps switch
closes, voltage flows to vanity mirror lamps. The van-
ity mirror is case grounded.
UNDERHOOD LAMP
Circuit A6 from fuse 16 in the Power Distribution
Center (PDC) supplies battery voltage for the under-
hood lamp. A mercury switch, in series after the
lamp, connects the lamp to ground on circuit Z1.
When the hood is raised, mercury inside the switch
moves to a position where it connects circuit M1 to
ground circuit Z1, illuminating the lamp.
CHIME/BUZZER MODULE
The buzzer or optional chime module sounds an au-
dible warning tone. The tone sounds for seat belt
warning and when the ignition key is in the ignition
switch while the drivers door is open. The tone also
sounds when the ignition key is in the ON position
while the drivers side seat belt is not buckled. Lastly,
the tone sounds when the headlamps are ON when
the ignition is OFF. Refer to Group 8U for system op-
eration.
When the ignition switch is in the RUN or START
position, circuit F87 from fuse 17 in the fuse block
supplies power to the chime/buzzer module. Circuit
A21 from the ignition switch supplies power to fuse
17.
Circuit L7 from fuse 15 in the fuse block also sup-
plies power to the chime/buzzer module. Circuit A3
from fuse 5 in the Power Distribution Center (PDC)
powers fuse 15.
When the parking lamps or headlamps are ON, the
headlamp switch connects circuit G26 with the driv-
ers side door jamb switch. Circuit G26 also connects
to the key-in switch. Circuit M11 connects the key-in
switch to the chime/buzzer module and the headlamp
switch.
If the headlamps are ON, and the drivers door
opens, ground for the chime/buzzer is on circuit C26
from the headlamp switch through the door jamb
switch to circuit Z1.
If the headlamps are OFF with the key in the ig-
nition while the drivers side door is open, ground forthe chime/buzzer is supplied through the key-in
switch. The ground path is over circuit M11, through
the closed key-in switch to circuit C26. From circuit
C26, the ground path continues through the drivers
door jamb switch to circuit Z1.
Circuit G11 from the buzzer powers the seat belt
warning lamp in the instrument cluster. Circuit Z1
at the instrument cluster provides ground for the
lamp.
Circuit G10 from the buzzer connects to the seat
belt switch. When the seat belt switch closes a path
to ground is completed on circuit Z1 and the tone
sounds momentarily.
Circuit Z1 also grounds the chime\buzzer module.
HELPFUL INFORMATION
Circuit F87 also powers the instrument cluster and
the headlamp delay module.
DIAGRAM INDEX
Component Page
Cargo Lamp............................8W-44-6
Chime/Buzzer Module......................8W-44-3
Courtesy Lamps.........................8W-44-5
Dome Lamp............................8W-44-7
Door Jamb Switches.....................8W-44-10
Fuse 3 (PDC).........................8W-44-4, 6
Fuse 5 (PDC).........................8W-44-3, 8
Fuse 6 (PDC)...........................8W-44-3
Fuse 9 (Fuse Block).....................8W-44-4, 6
Fuse 15 (Fuse Block)....................8W-44-3, 8
Fuse 16 (PDC)........................8W-44-4, 6
Fuse 17 (Fuse Block)......................8W-44-3
Fuse 19 (Fuse Block)......................8W-44-8
Glove Box Lamp and Switch.................8W-44-5
Headlamp Switch...................8W-44-3, 4, 5, 8
Headlamp Delay Module....................8W-44-4
Headlamp Delay Relay.....................8W-44-3
Ignition Switch..........................8W-44-3
Instrument Cluster........................8W-44-3
Instrument Panel Illumination Lamps..........8W-44-8, 9
Intermittent Wiper Control Module.............8W-44-4
Key-In Switch...........................8W-44-4
Liftgate Switch..........................8W-44-6
Reading Lamps..........................8W-44-7
Remote Keyless Entry Module................8W-44-7
Seat Belt Switch.........................8W-44-3
Telltale Connector (Instrument Cluster)...........8W-44-3
Time Delay Relay........................8W-44-4
Underhood Lamp.........................8W-44-4
Vanity Lamps...........................8W-44-7
8W - 44 - 2 8W-44 INTERIOR LIGHTINGÐXJ VEHICLESJ