1995 JEEP YJ body procedures

DIAGNOSIS
COMPASS/DISPLAY SELF-DIAGNOSTIC TEST
This self-diagnostic test is used to determine that
the compass and all of its display segments are oper-
ating properly electrically. Initiate the self-diagnostic
test as follows:
(1) With the ignition switch in the OFF position,
simultaneously press and hold the COMP/TEMP but-
ton and the US/METRIC button.
(2) Turn ignition switch to the ON position.
(3) Continue to hold both buttons until the display
performs a walking segment test. In this test all of
the compass points are displayed, along with various
number combinations. These combinations verify that
all display segments are functional. If any segment
should fail to light during the test, the unit is faulty
and requires replacement. To repeat the test, momen-
tarily depress and release the COMP/TEMP button
one time.
(4) Momentarily depress and release the US/MET-
RIC button one time and all segments will light si-
multaneously for about 2 seconds. If any segment
should fail to light during the test, the unit is faulty
and requires replacement. To repeat the test, momen-
tarily depress and release the COMP/TEMP button
one time.
(5) Momentarily depress and release the US/MET-
RIC button one time or turn the ignition switch to
OFF to exit the self-diagnostic mode and return to
normal operation.
If the compass functions, but accuracy is sus-
pect, it may be necessary to perform a variation
adjustment. This procedure allows the unit to
accommodate variations in the earth's mag-
netic field strength based on geographic loca-
tion. See Compass Variation Adjustment, in this
group.
If the compass display has blanked out and
only CAL appears, demagnetizing may be nec-
essary to remove excessive residual magnetic
fields from the vehicle. See Compass Demagne-
tizing, in this group.
THERMOMETER DIAGNOSIS
The thermometer function is supported by a tem-
perature sensor, a wiring circuit and a portion of the
overhead console display. The sensor is mounted at
the center of the vehicle below the grille, behind the
front bumper (Fig. 1).
If any portion of the circuit fails, it will self-diag-
nose as an open or short circuit. The system will dis-
play SC (short circuit) when the sensor is exposed to
temperatures in excess of 55ÉC (131ÉF) or if the cir-
cuit is shorted. If the temperature is below -40ÉC
(-40ÉF) or an open circuit exists, the system will dis-
play OC (open circuit).To diagnose the temperature sensor, perform the
following procedures. If the sensor and circuit are
OK, then the electronic module is faulty and should
be replaced.
SENSOR TEST
(1) Turn the ignition switch to OFF. Unplug sensor
connector.
(2) Measure resistance of sensor. At -40ÉF the re-
sistance is 336K ohms. At 140ÉF the resistance is
2.488K ohms. Sensor resistance should read between
these two values. If OK, go to Sensor Circuit Test. If
not OK, replace the sensor.
SENSOR CIRCUIT TEST
(1) Turn ignition switch to OFF. Unplug sensor
connector.
(2) Short the pins on the body half of connector us-
ing a jumper wire.
(3) Remove the overhead console as described in
Service Procedures.
(4) Check continuity between cavities 10 and 11 of
overhead console harness connector (Fig. 2). There
should be continuity. If OK, go to next step. If not
OK, repair open circuit as required.
Fig. 1 Temperature Sensor
8C - 2 OVERHEAD CONSOLEJ

(5) Probe cavity B1 of cluster connector A. Check
for continuity to a good ground. There should be no
continuity. If OK, go to next step. If not OK, repair
short circuit as required.
(6) Still probing cavity B1 of cluster connector A,
check for continuity to cavity B of sending unit body
half connector. There should be continuity. If OK, re-
place gauge. If not OK, repair open circuit as re-
quired.
OIL PRESSURE GAUGE
The diagnosis found here addresses an inoperative
gauge condition. If the problem being diagnosed is re-
lated to gauge accuracy, be certain to confirm that
problem is with gauge and not with engine oiling sys-
tem performance. Actual engine oil pressure should
be checked with a test gauge and compared to gauge
readings before you proceed with gauge diagnosis.
Refer to Group 9 - Engines for more information.
(1) Turn ignition switch to ON. Disconnect oil pres-
sure sending unit connector. The sending unit (Fig. 3)
is located on right side of engine block. On 2.5L en-
gine, it is just forward of ignition distributor and just
to the rear of generator mounting bracket. On 4.0L
engine, it is just to the rear of ignition distributor
and above oil filter adapter. The gauge needle should
move to high end of gauge scale. If OK, go to next
step. If not OK, go to step 3.
(2) Install a jumper wire from sending unit wiring
to ground. The gauge needle should move to low end
of gauge scale. If OK, replace sending unit. If not
OK, remove jumper wire and go to next step.
(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Remove instrument cluster bezel and
cluster assembly. Disconnect instrument cluster con-
nector A.
(4) Probe cavity B7 (cavity B8 - RHD) of cluster
connector A. Check for continuity to a good ground.
There should be no continuity. If OK, go to next step.
If not OK, repair short circuit as required.(5) Still probing cavity B7 (cavity B8 - RHD) of
cluster connector A, check for continuity to sending
unit wire connector. There should be continuity. If
OK, replace gauge. If not OK, repair open circuit as
required.
SPEEDOMETER/ODOMETER
The diagnosis found here addresses an inoperative
gauge condition. If the problem being diagnosed is re-
lated to gauge accuracy, be certain to confirm that
problem is with gauge and not with incorrect speed-
ometer pinion, axle ratio or tire size. Refer to Group
21 - Transmission and Transfer Case for more infor-
mation.
(1) Perform vehicle speed sensor test as described
in the appropriate Powertrain Diagnostic Procedures
manual. If OK, go to next step. If not OK, replace ve-
hicle speed sensor.
(2) Disconnect battery negative cable. Unplug vehi-
cle speed sensor, PCM, and daytime running lamp
module connectors. Remove instrument cluster bezel
and cluster assembly. Disconnect instrument cluster
connector A.
(3) Probe cavity A5 (cavity B6 - RHD) of cluster
connector A. Check for continuity to a good ground.
There should be no continuity. If OK, go to next step.
If not OK, repair short circuit as required.
(4) Still probing cavity A5 (cavity B6 - RHD) of
cluster connector A, check for continuity to cavity 1 of
vehicle speed sensor connector (Fig. 4). There should
be continuity. If OK, replace speedometer/odometer. If
not OK, repair open circuit as required.
TACHOMETER
(1) With engine running, check for tachometer sig-
nal at pin 43 of PCM connector (Fig. 5). See Tachom-
eter Calibration chart in Specifications. If OK, go to
next step. If not OK, replace PCM.
Fig. 2 Fuel Gauge Sending Unit ConnectorFig. 3 Oil Pressure Switch/Sending Unit - Typical
8E - 6 INSTRUMENT PANEL AND GAUGESÐXJJ

continuity. If OK, go to next step. If not OK, repair
circuit to ground as required.
(4) Remove center instrument cluster bezel and
gauge package cluster assembly. Disconnect cluster
connector.
(5) Probe cavity 6 of cluster connector. Check for
continuity to a good ground. There should be no con-
tinuity. If OK, go to next step. If not OK, repair short
circuit as required.
(6) Still probing cavity 6 of cluster connector, check
for continuity to cavity 2 of sending unit wiring body
half connector. There should be continuity. If OK, re-
place gauge. If not OK, repair open circuit as re-
quired.
OIL PRESSURE GAUGE
The diagnosis found here addresses an inoperative
gauge condition. If the problem being diagnosed is re-
lated to gauge accuracy, be certain to confirm that
problem is with gauge and not with engine oiling sys-
tem performance. Actual engine oil pressure should
be checked with a test gauge and compared to gauge
readings before you proceed with gauge diagnosis.
Refer to Group 9 - Engines for more information.
(1) Turn ignition switch to ON. Disconnect oil pres-
sure sending unit connector. The sending unit (Fig. 3)
is located on right side of engine block. On 2.5L en-
gine, it is just forward of ignition distributor and just
to the rear of generator mounting bracket. On 4.0L
engine, it is just to the rear of ignition distributor
and above oil filter adapter. The gauge needle should
move to high end of gauge scale. If OK, go to next
step. If not OK, go to step 3.
(2) Install a jumper wire from sending unit wiring
to ground. The gauge needle should move to low end
of gauge scale. If OK, replace sending unit. If not
OK, remove jumper wire and go to next step.(3) Turn ignition switch to OFF. Disconnect battery
negative cable. Remove center instrument cluster be-
zel and gauge package cluster assembly. Disconnect
cluster connector.
(4) Probe cavity 9 of cluster connector. Check for
continuity to a good ground. There should be no con-
tinuity. If OK, go to next step. If not OK, repair short
circuit as required.
(5) Still probing cavity 9 of cluster connector, check
for continuity to sending unit wire connector. There
should be continuity. If OK, replace gauge. If not OK,
repair open circuit as required.
SPEEDOMETER/ODOMETER
The diagnosis found here addresses an inoperative
gauge condition. If the problem being diagnosed is re-
lated to gauge accuracy, be certain to confirm that
problem is with gauge and not with incorrect speed-
ometer pinion, axle ratio or tire size. Refer to Group
21 - Transmission and Transfer Case for more infor-
mation.
(1) Perform vehicle speed sensor test as described
in the appropriate Powertrain Diagnostic Procedures
manual. If OK, go to next step. If not OK, replace ve-
hicle speed sensor.
(2) Disconnect battery negative cable. Unplug vehi-
cle speed sensor, PCM, and daytime running lamp
module connectors. Remove left instrument cluster
bezel and main cluster assembly. Disconnect cluster
connector.
(3) Probe cavity 13 of cluster connector. Check for
continuity to a good ground. There should be no con-
tinuity. If OK, go to next step. If not OK, repair short
circuit as required.
(4) Still probing cavity 13 of cluster connector,
check for continuity to cavity 1 of vehicle speed sen-
sor connector (Fig. 4). There should be continuity. If
OK, replace speedometer/odometer. If not OK, repair
open circuit as required.
Fig. 2 Fuel Gauge Sending Unit ConnectorFig. 3 Oil Pressure Sending Unit - Typical
8E - 28 INSTRUMENT PANEL AND GAUGESÐYJJ

(3) Remove screws holding speaker grille and
speaker to bar.
(4) Disconnect wires from speaker and remove
speaker.
(5) Reverse removal procedures to install.
SOUND BAR REMOVE/INSTALL - YJ
(1) Disconnect speaker harness connector located
on the passenger side at the sound bar (Fig. 19)
(2) Remove bolts attaching the sound bar side
flanges to the right and left side bars.
(3) Open zipper on sport bar cover.
(4) Remove bolts attaching the sound bar brackets
to the sport bar (located on the rear of the sport bar)
(Fig. 20). Slip brackets through the sport bar cover.
(5) Reverse removal procedures to install.
ANTENNA REMOVE/INSTALL - YJ
(1) Remove the radio. See Radio Remove/Install, in
this group for procedures.
(2) Remove three screws holding the antenna base
and pad to the body (Fig. 21).
(3) Pull the antenna and cable out of the vehicle.(4) To install the antenna, make sure the antenna
pad is placed over the cable and guide the cable un-
der the instrument panel.
(5) Secure the antenna base and pad with three
screws.
(6) Install the antenna lead into the radio and in-
stall the radio.
Fig. 19 Sound Bar Speaker Connector - YJ
Fig. 20 Sound Bar Attaching Bolt - YJ
Fig. 21 Antenna Remove/Install - YJ
8F - 10 AUDIO SYSTEMSJ

HORNS
CONTENTS
page page
DIAGNOSIS............................. 2
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 3
SPECIFICATIONS......................... 5
GENERAL INFORMATION
Following are general descriptions of the major
components in the XJ (Cherokee)/YJ (Wrangler) horn
systems. Refer to Group 8W - Wiring Diagrams for
complete circuit descriptions and diagrams.
HORN SWITCH
XJ
Two horn switches are installed in the steering
wheel, one on each side of the center-mounted driv-
er's airbag module. When either switch is depressed
it completes a circuit to ground for the coil side of the
horn relay. The steering wheel and steering column
must be properly grounded for the horn switches to
function. The horn switches are only serviced as a set
with their wiring. If either switch should fail, both
switches must be replaced.
YJ
A single switch is installed in the center of the
steering wheel, directly under the horn button. When
the horn button is depressed the switch completes a
circuit to ground for the coil side of the horn relay.
The steering wheel and steering column must be
properly grounded for the horn switch to function.
The horn switch is available for service.
HORN RELAY
On XJ models, the horn relay is a mini-relay in-
stalled in the relay center, which is mounted to the
lower instrument panel reinforcement inboard of thesteering column. On YJ models, the horn relay is a
ISO relay installed in the Power Distribution Center
(PDC) near the battery tray. Refer to underside of
PDC cover for relay identification.
One side of the horn relay electromagnetic coil re-
ceives battery voltage at all times. When a horn
switch is depressed, the other side of the relay coil is
grounded. The energized relay coil causes the nor-
mally open relay contacts to close, providing battery
voltage to the horn.
If a problem is encountered with a continuously
sounding horn, it can usually be quickly resolved by
removing the horn relay until further diagnosis is
completed.
HORNS
On YJ models, a standard single, low-note, dia-
phragm-type horn is mounted and grounded to the
left inner fender shield under the hood. Dual horns
are standard equipment on XJ models. The high-note
diaphragm-type horn is mounted and grounded to
the left radiator closure panel brace behind the front
bumper. The low-note diaphragm-type horn is con-
nected in parallel with the high-note horn and is
mounted and grounded to the right radiator closure
panel brace behind the front bumper.
On XJ models, a cadmium-plated screw is
used to attach the horns to the body. Do not
substitute other types of screws as they may be-
come corroded and cause a loss of ground.
JHORNS 8G - 1

SERVICE PROCEDURES
HORN REMOVE/INSTALL
XJ
(1) Raise and support the vehicle.
(2) Remove the front underbody splash shield.
(3) Remove horn mounting bolt and horn (Fig. 3).
(4) Remove wire from horn.
(5) Reverse removal procedures to install.
YJ
(1) Disconnect wire harness connector from the
horn (Fig. 4).
(2) Remove horn and bracket mounting bolt. Horn
and bracket are removed as an assembly.
(3) Reverse removal procedures to install.
HORN SWITCH REMOVE/INSTALL
WARNING: ON VEHICLES EQUIPPED WITH AN AIR-
BAG, REFER TO GROUP 8M - RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE PROPER PRECAUTIONS COULD RESULT
IN ACCIDENTAL AIRBAG DEPLOYMENT AND POS-
SIBLE PERSONAL INJURY.
XJ
(1) Disconnect negative cable from battery and iso-
late.
(2) Using a small screwdriver, remove plastic cover
plug from top outer surface of steering wheel hub
(Fig. 5). Exit vehicle and disarm airbag by reaching
through driver's side window and turning arming
screw counter-clockwise to its travel limit. 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. This
is done using a 10mm socket and manual drive. DO
NOT USE POWER-DRIVEN TOOLS.
(4) Remove airbag module from steering wheel.
(5) To access horn switch retaining screws, pry out
trim cover buttons on back of steering wheel spokes
directly behind horn switches. Remove retaining
screws.
(6) Disconnect horn switch wires located in the
lower portion of steering wheel hub cavity and re-
move switches from steering wheel.
(7) Reverse removal procedures to install. Tighten
hardware as follows:
²airbag module nuts-9to11Nzm (80 to 100 in.
lbs.)
²airbag arming screw - not to exceed 1 to 1.5 Nzm
(10 to 15 in. lbs.).
YJ
(1) Disconnect negative cable from battery.
(2) Remove horn button by pulling straight up.
Fig. 3 Horn Mounting - XJ
Fig. 4 Horn Mounting - YJ
JHORNS 8G - 3

VEHICLE SPEED CONTROL SYSTEM
CONTENTS
page page
DIAGNOSIS............................. 2
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 9
GENERAL INFORMATION
The vehicle speed control system (Fig. 1) is an
available option on all XJ (Cherokee) models. The
system is electronically controlled and vacuum oper-
ated. Following are general descriptions of the major
components in the vehicle speed control system. Re-
fer to Group 8W - Wiring Diagrams for complete cir-
cuit descriptions and diagrams.
SPEED CONTROL SERVO
The speed control servo is mounted to a bracket on
the right side inner fender shield in the engine com-
partment. The servo unit consists of a solenoid valve
body, a vacuum servo and the mounting bracket. The
PCM controls the solenoid valve body. The solenoid
valve body controls the application and release of
vacuum to the diaphragm of the vacuum servo. The
servo unit cannot be repaired and is serviced only as
a complete assembly.
SPEED CONTROL SWITCH
The speed control switch module is mounted to the
center of the steering wheel below the driver's airbag
module. The PCM monitors the state of the speed
control switches. The individual switches are labeled:
OFF/ON, RESUME/ACCEL, SET/COAST. Refer to
the owner's manual for more information on speed
control switch functions and setting procedures. The
individual switches cannot be repaired. If one switch
fails, the entire switch module must be replaced.
STOP LAMP SWITCH
Vehicles with the speed control option use a dual
function stop lamp switch. The switch is mounted in
the same location as the conventional stop lamp
switch, on the brake pedal mounting bracket under
the instrument panel. The PCM monitors the state of
the dual function stop lamp switch. Refer to Group 5
- Brakes for more information on stop lamp switch
service and adjustment procedures.
SERVO CABLE
The speed control servo cable is connected betweenthe speed control vacuum servo diaphragm and the
throttle control linkage. This cable causes the throt-
tle control linkage to open or close the throttle valve
in response to movement of the vacuum servo dia-
phragm.
POWERTRAIN CONTROL MODULE
The speed control electronic control circuitry is in-
tegrated into the Powertrain Control Module (PCM).
The PCM is located in the engine compartment on
the left side inner fender shield. The PCM speed con-
trol functions are monitored by the On-Board Diag-
nostics (OBD). All OBD-sensed systems are
monitored by the PCM. Each monitored circuit is as-
signed a Diagnostic Trouble Code (DTC). The PCM
will store a DTC in electronic memory for any failure
it detects. See Using On-Board Diagnostic System in
this group for more information. The PCM cannot be
repaired and must be replaced if faulty.
VACUUM RESERVOIR
The vacuum reservoir is mounted behind the left
end of the front bumper bar. The reservoir contains a
one-way check valve to trap engine vacuum in the
reservoir. When engine vacuum drops, as in climbing
a grade while driving, the reservoir supplies the vac-
uum needed to maintain proper speed control opera-
tion. The vacuum reservoir cannot be repaired and
must be replaced if faulty.
VEHICLE SPEED SENSOR
The Vehicle Speed Sensor (VSS) is a pulse genera-
tor mounted to an adapter near the transmission
(two-wheel drive) or transfer case (four-wheel drive)
output shaft. The sensor is driven through the
adapter by a speedometer pinion gear. The VSS pulse
signal to the speedometer/odometer is monitored by
the PCM speed control circuitry to determine vehicle
speed and to maintain speed control set speed. Refer
to the appropriate Powertrain Diagnostic Procedures
manual for testing of this component. Refer to Group
14 - Fuel System for service of this component.
JVEHICLE SPEED CONTROL SYSTEM 8H - 1

LAMPS
CONTENTS
page page
BULB APPLICATIONÐXJ VEHICLES......... 18
GENERAL INFORMATION.................. 1INTERIOR LAMPS....................... 16
SERVICE PROCEDURES................... 6
GENERAL INFORMATION
Each vehicle is equipped with various lamp assem-
blies. A good ground is necessary for proper lighting
operation. Grounding is provided by the lamp socket
when it comes in contact with the metal body, or
through a separate ground wire.
When changing lamp bulbs check the socket for
corrosion. If corrosion is present, clean it with a wire
brush and coat the inside of the socket lightly with
Mopar Multi-Purpose Grease or equivalent.
DIAGNOSTIC PROCEDURESÐXJ
When a vehicle experiences problems with the
headlamp system, verify the condition of the batteryconnections, charging system, headlamp bulbs, wire
connectors, relay, high beam dimmer switch and
headlamp switch. Refer to Group 8W, Wiring Dia-
grams for component locations and circuit informa-
tion.
Always begin any diagnosis by testing all of the
fuses and circuit breakers in the system. Refer to
Group 8W, Wiring Diagrams.
JLAMPS 8L - 1