1994 JEEP CHEROKEE Service Repair Manual

INSTRUMENT PANEL AND GAUGESÐYJE
CONTENTS
page page
GAUGE PACKAGE DIAGNOSIS............ 22
GAUGE PACKAGE GENERAL INFORMATION . 22
GAUGE PACKAGE SERVICE PROCEDURES . . 24
INSTRUMENT CLUSTER DIAGNOSIS....... 14INSTRUMENT CLUSTER GENERAL INFORMATION.14
INSTRUMENT CLUSTER SERVICE PROCEDURES.. 17
SPECIFICATIONS....................... 27
INSTRUMENT CLUSTER GENERAL INFORMATION
SPEEDOMETER/ODOMETER SYSTEM
The speedometer/odometer system consists of an
electric speedometer and pushbutton reset odometer
mounted in the cluster. The system also includes the
wire harness from the cluster to the vehicle speed
sensor at the transmission, and the adapter and pin-
ion in the transmission. A signal is sent from a
transmission mounted vehicle speed sensor to the
speedometer/odometer circuitry through the wiring
harness. Refer to Group 21 - Transmission for select-
ing the proper pinion, and selecting and indexing the
proper adapter.
TACHOMETER
The tachometer displays the engine speed (RPM).
With the engine running, the tachometer receives anengine speed signal from the Powertrain Control
Module pin 43 (values shown in Specifications chart).
INDICATOR LAMPS
The Brake, Upshift (2.5L with 5 speed transmis-
sion except California), and Malfunction Indicator
(Check Engine) lamps are located in the indicator
lamp panel above the steering column. The lamps
share a common battery feed connection through the
ignition switch and fuse #9.
The turn signals, high beam indicator, seat belt re-
minder, hazard lamp, master lighting and illumina-
tion bulbs are supplied battery voltage through
various switches and share a common ground.
INSTRUMENT CLUSTER DIAGNOSIS
INDEX
page page
Brake Indicator Lamp...................... 16
DiagnosingÐAll Lamps Out................. 16
Instrument Panel Illumination Lamps.......... 16
Malfunction Indicator Lamp (Check Engine)..... 16Seat Belt Reminder Lamp................... 16
Speedometer............................ 14
Tachometer............................. 14
Upshift Indicator Lamp..................... 16
SPEEDOMETER
(1) Raise vehicle.
(2) Disconnect the vehicle speed sensor connector.
(3) Connect a voltmeter between the black wire
pin of the connector and ground.
(4) Turn the ignition switch to the ON position.
(5) Check for approximately 5 volts. If OK, per-
form vehicle speed sensor test. Refer to the appropri-
ate Powertrain Diagnostic Procedures manual. If not
OK, continue with step 6.
(6) Turn ignition switch to OFF position.(7) Check continuity between vehicle speed sensor
connector and terminal 13 of instrument cluster con-
nector. If OK, replace speedometer. If not OK, repair
open circuit.
TACHOMETER
(1) Tachometer input is from the Powertrain Con-
trol Module (PCM) pin 43. Use the DRB scan tool to
perform actuator test. If OK, continue with step 2. If
not, replace PCM.
(2) Check for continuity between cluster connector
pin 12 and PCM pin 43. If OK, replace tachometer. If
not, repair open circuit.
8E - 14 YJ INSTRUMENT PANEL AND GAUGESJ

INSTRUMENT CLUSTER
JYJ INSTRUMENT PANEL AND GAUGES 8E - 15

DIAGNOSINGÐALL LAMPS OUT
(1) Inspect fuse #9. Replace as required.
(2) Measure voltage at instrument cluster connec-
tor terminal 20. Meter should read zero ohms. If not,
repair open to ground.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. The lamp is con-
trolled by the PCM. The lamp lights to indicate when
the driver should shift to the next highest gear for best
fuel economy. The PCM will turn the lamp off after 3 to
5 seconds if the upshift is not performed. The lamp will
remain off until the vehicle stops accelerating and is
brought back to the range of lamp operation or shifted
into another gear.
The indicator lamp is normally illuminated when
the ignition switch is turned ON and it is turned off
when the engine is started. The lamp will be lighted
during engine operation according to engine speed
and load.
(1) Turn ignition switch to ON.
(2) Ground pin 2 of cluster connector. Lamp should
light. If not, replace bulb. If OK, continue with step 3.
(3) Turn ignition switch to OFF. Check for conti-
nuity between cluster connector pin 2 and pin 54 of
the PCM. If not, repair open. If OK, refer to DRB
scan tool actuator test of upshift indicator.
BRAKE INDICATOR LAMP
The brake indicator is a dual function lamp. It will in-
dicate an unequal pressure condition in the split brake
hydraulic system and it also will indicate when the park-
ing brake is engaged. Separate switches are used for each
indicator lamp function. A switch mounted on the brake
pedal assembly will close a ground circuit whenever the
parking brakes are applied. A second switch is installed
in the brake hydraulic lines near the master cylinder. If
the switch is balanced by equal pressure on both ends of
the switch valve, the valve remains centered and the
lamp remains off. If the valve is shifted by unequal pres-
sure between the front or rear brake hydraulic systems,
the lamp circuit is connected to ground. To make sure
the brake lamp is functional before the vehicle is driven,
it is illuminated through a ground circuit when the igni-
tion switch is turned to the START position.
(1) Turn ignition switch to ON.
(2) Ground pin 1 of the cluster connector. Lamp
should light. If not, replace bulb. If OK, continue
with step 3.
(3) Turn ignition switch to OFF. Check for continuity to
park brake switch and brake warning switch.
MALFUNCTION INDICATOR LAMP (CHECK ENGINE)
The Malfunction Indicator Lamp (Check Engine) il-
luminates each time the ignition switch is turned
ON and stays on for 3 seconds as a bulb test.If the PCM receives an incorrect signal or no signal
from certain sensors or emission related systems the
lamp is turned on (pin 32 of PCM). This is a warning
that the PCM has recorded a system or sensor mal-
function. In some cases when a diagnostic fault is de-
clared the PCM will go into a limp-in mode in an
attempt to keep the system operating. It signals an
immediate need for service.
The lamp also can be used to display diagnostic
trouble codes (DTC). Cycle the ignition switch ON,
OFF, ON, OFF, ON within 5 seconds. This will allow
any DTC's stored in the PCM memory to be dis-
played in a series of flashes representing digits.
(1) Turn ignition switch to ON.
(2) Ground pin 4 of cluster connector. Lamp should
light. If not, replace bulb. If OK, continue with step 3.
(3) Turn ignition switch to OFF. Check for conti-
nuity between cluster connector pin 4 and PCM cav-
ity 32. If OK, replace PCM. If not, repair open.
SEAT BELT REMINDER LAMP
Apply 12 volts to terminal 16 of cluster connector.
Lamp should light. If not, replace bulb. If OK, check
wiring for an open to buzzer module. Refer to Group
8U - Chime/Buzzer Warning Systems.
INSTRUMENT PANEL ILLUMINATION LAMPS
The instrument panel illumination lamps share
two common connections. There is a splice after fuse
#10 that connects the lamps to battery feed. There is
also a splice that connects all lamps to ground. Be-
cause they share these common connection points in
a parallel circuit, the illumination lamps will all
come on at the same time. It also means one or more
lamps can be out without affecting the operation of
the other lamps.
On the battery side of the circuit, the headlamp
switch illumination rheostat/switch and panel lamps
fuse receive battery feed in series from the park/tail
fuse. In the park lamp position, the headlamp switch
completes the circuit from the park/tail fuse to the il-
lumination rheostat/switch and panel lamps fuse.
The illumination rheostat contains a variable resis-
tor that allows the driver to vary illumination inten-
sity from off to full brightness.
DIAGNOSIS
(1) Turn parking lamps ON.
(2) Check fuse #10. Replace as required.
(3) Measure voltage at battery side of fuse #10
with rheostat turned counterclockwise to clockwise
(LO to HI). Meter should read zero volts to battery
voltage. If not, replace headlamp switch.
(4) Measure resistance at ground side of fuse #10
with parking lamps OFF. Meter should read almost
zero ohms (except bulb filament). If not, repair open
to ground. If zero ohms, 12 volt supply wire from fuse
is shorted to ground, repair short.
8E - 16 YJ INSTRUMENT PANEL AND GAUGESJ

INSTRUMENT CLUSTER SERVICE PROCEDURES
INDEX
page page
Headlamp Switch/Illumination Rheostat........ 21
Indicator Bezel Replacement................ 17
Instrument Cluster Bulb Replacement......... 19
Instrument Cluster Replacement............. 17Printed Circuit Replacement................ 19
Rear Defogger/Fog Lamp/Rear Wiper Switches . . 21
Speedometer Replacement................. 17
Tachometer Replacement.................. 17
INSTRUMENT CLUSTER REPLACEMENT
(1) Remove 6 shroud screws (Fig. 1).
(2) Slide shroud toward steering wheel.
(3) Remove 3 screws holding right side switch
panel (Fig. 2).
(4) Remove 3 screws holding left side switch bezel.(5) Remove 2 screws holding cluster in place.
(6) Lift up top of cluster. Roll cluster out between
steering column and instrument panel far enough to
reach connector located behind tachometer.
(7) Disconnect cluster connector and remove clus-
ter (Fig. 3).
(8) To install cluster, reverse the removal proce-
dures.
TACHOMETER REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrumentation shroud (Fig. 1). Refer
to Instrument Cluster Replacement.
(3) Remove cluster as described in Instrument
Cluster replacement.
(4) Remove 3 screws and tachometer lens (Fig. 4).
(5) Gently pry up clip to release lens from bezel
(Fig. 5).
(6) Remove 3 screws from rear of housing (Fig. 6).
Remove tachometer.
(7) Install tachometer with 3 screws.
(8) Snap lens into place.
(9) Install lens with 3 screws.
(10) To install the cluster, reverse the removal pro-
cedures.
SPEEDOMETER REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrument shroud (Fig. 1). Refer to In-
strument Cluster Replacement.
(3) Remove cluster as described in Instrument
Cluster Replacement.
(4) Remove 3 screws and speedometer lens (Fig. 7).
(5) Gently pry up clip to release lens from bezel
(Fig. 5).
(6) Remove 3 screws from rear of housing (Fig. 8).
Remove speedometer.
(7) Install speedometer with 3 screws.
(8) Snap lens into place.
(9) Install lens with 3 screws.
(10) To install the cluster, reverse the removal pro-
cedures.
INDICATOR BEZEL REPLACEMENT
(1) Disconnect negative cable from battery.
(2) Remove instrumentation shroud (Fig. 1).
(3) Remove 3 screws and tachometer lens (Fig. 4).
Fig. 2 Cluster Removal
Fig. 1 Instrument Shroud Removal/Installation
JYJ INSTRUMENT PANEL AND GAUGES 8E - 17

Fig. 3 Instrument Cluster
8E - 18 YJ INSTRUMENT PANEL AND GAUGESJ

(4) Gently pry up clip to release lens from bezel
(Fig. 5).
(5) Remove 3 screws and speedometer lens (Fig. 7).
(6) Gently pry up clip to release lens from bezel
(Fig. 5).
(7) Remove indicator bezel (Fig. 3).
(8) Lift indicator panel off locating pins.
(9) Reverse removal procedures to install new
panel and bezel.
(10) Install speedometer and tachometer lenses.
(11) Install shroud.(12) Install negative cable to battery.INSTRUMENT CLUSTER BULB REPLACEMENT
Refer to Printed Circuit Replacement for bulb re-
placement.
PRINTED CIRCUIT REPLACEMENT
Remove cluster as described in cluster replacement.
DISASSEMBLY
(1) Remove all attaching screws for speedometer
and tachometer (Fig. 9).
Fig. 4 Tachometer Lens
Fig. 5 Cluster Lens Retaining Clip
Fig. 6 Tachometer Removal/Installation
Fig. 7 Speedometer Lens
JYJ INSTRUMENT PANEL AND GAUGES 8E - 19

(2) Remove 2 screws holding cluster connector re-
taining plate to housing (Fig. 10).
(3) To remove plate, slide it toward bottom of hous-
ing (Fig. 11).
(4) Remove lamp sockets from circuit board.(5) Remove printed circuit including connector.
ASSEMBLY
(1) Position printed circuit, including connector, on
the back of instrument panel cluster.
Fig. 8 Speedometer Removal/Installation
Fig. 9 Printed Circuit Removal/Installation
Fig. 10 Printed Circuit Connector Attaching Screws
8E - 20 YJ INSTRUMENT PANEL AND GAUGESJ

(2) Remove gauge bezel and lens.
(3) Hold components in place and install screws.
(4) Install lamp sockets.
(5) Pivot connector up and install retaining plate.
(6) Install gauge bezel and cluster lens.
HEADLAMP SWITCH/ILLUMINATION RHEOSTAT
(1) Disconnect negative cable from battery.
(2) Remove instrument cluster shroud (Fig. 1).
(3) Remove 3 screws holding switch bezel (Fig. 12).
(4) Remove 2 screws from the appropriate switch
to be replaced (Fig. 13).
(5) Remove the switch connector.
(6) Reverse the removal procedures for installa-
tion.
REAR DEFOGGER/FOG LAMP/REAR WIPER
SWITCHES
(1) Disconnect negative cable from battery.
(2) Remove instrument cluster shroud (Fig. 1).
(3) Remove 3 screws holding switch bezel (Fig. 14).
(4) Remove the switch connector.
(5) Release tabs holding switch and remove switch.
(6) Reverse the removal procedures for installa-
tion.
Fig. 11 Cluster Connector Retaining Strap
Fig. 12 Left Hand Instrument Panel Switch Bezel.
Fig. 13 Headlamp Switch/Illumination Rheostat
Fig. 14 Right Hand Instrument Panel Switch Bezel
JYJ INSTRUMENT PANEL AND GAUGES 8E - 21