1995 JEEP YJ power steering

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

DIAGNOSIS
When diagnosing the turn signal or hazard warning
circuits, remember that high generator output can
burn out bulbs rapidly and repeatedly. If this is a
problem on the vehicle being diagnosed, refer to
Group 8A - Battery/Starting/Charging Systems Diag-
nostics to test charging system.
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.
TURN SIGNAL/HAZARD WARNING SYSTEM - XJ
(1) Turn ignition switch to ON position. Actuate the
turn signal lever or hazard warning button. Observe
the turn indicator lamp(s) in the instrument cluster.
If the flash rate is very high, check for a turn signal
bulb that is not lit. Replace that bulb or repair cir-
cuits to that lamp, as required. Test operation. If turn
indicator does not light, continue to next step.
(2) Remove and inspect fuse 8 (turn signals) in
fuseblock module, or fuse F13 (hazard warning) in the
Power Distribution Center. Replace fuse, if required.
(3) Remove combination flasher from relay center
and replace with a known good unit. Test operation of
turn signal and hazard warning systems. If OK, re-place faulty combination flasher. If not OK, remove
test flasher and go to next step.
(4) With ignition switch in ON position, check for
battery voltage at cavity for flasher terminal J1 (Fig.
2). If OK, go to next step. If not OK, repair circuit to
ignition switch as required.
(5) With ignition switch in OFF position, check for
battery voltage at cavity for flasher terminal J2. If
OK, go to next step. If not OK, repair circuit to Power
Distribution Center as required.
(6) With ignition switch in OFF position, check for
continuity between cavity for flasher terminal J5 and
a good ground. There should be continuity. If OK, go
to next step. If not OK, repair circuit to ground as
required.
(7) Locate the multi-function switch connector. See
Multi-Function Switch, in this group. Check for conti-
nuity between cavity for flasher terminal J3 and cav-
ity 13 of the multi-function switch connector. There
should be continuity. If OK, go to next step. If not OK,
repair open circuit as required.
(8) Check for continuity between cavity for flasher
terminal J4 and cavity 17 of the multi-function switch
connector. There should be continuity. If OK, test
multi-function switch. If not OK, repair open circuit
as required.
TURN SIGNAL SYSTEM - YJ
A turn signal indicator lamp that remains lit (with-
out flashing) is an indication of a burned out exterior
turn signal bulb or faulty exterior lamp circuit. Check
Fig. 2 Combination Flasher Circuit - XJ
JTURN SIGNAL AND HAZARD WARNING SYSTEMS 8J - 3

lamps and repair circuits or replace bulbs as re-
quired. If system still does not function properly, pro-
ceed as follows.
(1) Locate fuseblock module under driver's side of
instrument panel. Remove and inspect fuse 4. If OK,
go to next step. If not OK, replace fuse as required.
(2) Replace turn signal flasher (light blue can in
fuseblock module) with a known good unit. Test op-
eration. If OK, replace faulty turn signal flasher. If
not OK, remove test flasher and go to next step.
(3) Turn ignition switch to ACCESSORY position.
Check for battery voltage at flasher cavity on left
(closest to hazard flasher). If OK, go to next step. If
not OK, repair circuit to fuse 4 as required.
(4) Turn ignition switch to OFF position. See Turn
Signal/Hazard Warning Switch Remove/Install to lo-
cate steering column connector. Unplug connector.
(5) Turn ignition switch to ACCESSORY position.
Check for battery voltage at connector terminal L. If
OK, replace turn signal/hazard warning switch. If not
OK, repair circuit between turn signal flasher and
steering column connector.
HAZARD WARNING SYSTEM - YJ
(1) Locate Power Distribution Center (PDC) near
battery tray in engine compartment. Remove and in-
spect fuse F5. If OK, go to next step. If not OK,
replace fuse as required.(2) Replace hazard warning flasher (metal can in
fuseblock module) with a known good unit. Test op-
eration. If OK, replace faulty hazard warning flasher.
If not OK, remove test flasher and go to next step.
(3) Check for battery voltage at flasher cavity on
left (closest to hazard flasher). If OK, go to next step.
If not OK, repair circuit to fuse F5 in PDC as re-
quired.
(4) See Turn Signal/Hazard Warning Switch Re-
move/Install to locate steering column connector. Un-
plug connector.
(5) Check for battery voltage at connector terminal
K. If OK, replace turn signal/hazard warning switch.
If not OK, repair circuit between hazard warning
flasher and steering column connector.
MULTI-FUNCTION SWITCH - XJ
(1) Access multi-function switch connector and re-
move. See service procedures for Multi-Function
Switch, in this group.
(2) Using an ohmmeter, perform switch continuity
checks at the switch terminals as shown in the chart
(Fig. 3).
Fig. 3 Multi-Function Switch Continuity
8J - 4 TURN SIGNAL AND HAZARD WARNING 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

POWER LOCKS
CONTENTS
page page
DIAGNOSIS............................. 2
GENERAL INFORMATION.................. 1SERVICE PROCEDURES................... 8
GENERAL INFORMATION
Power locks are optional equipment on XJ (Chero-
kee) models. Power windows and the keyless entry
system are included on vehicles equipped with the
power lock option. All doors and the liftgate can be
locked and unlocked electrically by operating the
switch on either front door panel, or by operating the
lock and unlock buttons of the remote keyless entry
transmitter. The power lock and keyless entry sys-
tems operate with battery power supplied indepen-
dent of the ignition switch.
Following are general descriptions of the major
components in the power lock system. Refer to Group
8W - Wiring Diagrams for complete circuit descrip-
tions and diagrams. Refer to the owner's manual for
more information on the features and use of these
systems.
POWER LOCK SWITCH
The power locks are controlled by a two-way switch
mounted on the trim panel of each front door. The
switch controls battery feed to the lock and unlock
relays. The door lock switches can not be repaired. If
faulty, the entire switch must be replaced.
POWER LOCK/UNLOCK RELAYS
The power lock and unlock relays are located in the
relay center. The relay center is located on the lower
instrument panel reinforcement behind the lower in-
strument panel and just right of the steering column.
The relays respond to inputs from the power lock
switches and the keyless entry module by sending
the correct battery and ground feeds to the lock mo-
tors. The lock and unlock relays can not be repaired.
If faulty, they must be replaced.
POWER LOCK MOTOR
The locks are actuated by a reversible motor
mounted within each door. The motor direction iscontrolled by the battery and ground feeds from the
power lock/unlock relays. The motor can not be re-
paired. If faulty, the entire motor must be replaced.
KEYLESS ENTRY TRANSMITTER
The keyless entry transmitter is equipped with two
buttons labeled Lock and Unlock. It is also designed
to serve as a key fob and is equipped with a key ring.
Each transmitter has a different vehicle access code,
which must be programmed into the memory of the
keyless entry module in the vehicle in order to oper-
ate the locks. The operating range of the infrared
transmitter signal is up to 4.75 meters (15 feet) from
the receiver.
The transmitter operates on two CR1616 3-volt (or
equivalent) batteries. Typical battery life is from one
to two years.
KEYLESS ENTRY MODULE
The keyless entry module is mounted in a housing
on the headliner near the windshield between the
sunvisors, or inside and towards the rear of the over-
head console (if equipped). This module contains the
keyless entry receiver and program logic for the key-
less entry system.
The keyless entry module has a memory function
to retain the vehicle access code of at least one, and
up to four transmitters. The module receives input
from the remote keyless entry transmitter. In re-
sponse to that input, it is programmed to control out-
puts to the lock and unlock relays. The module can
not be repaired and, if faulty, must be replaced.
JPOWER LOCKS 8P - 1

(8) Reverse removal procedures to install. Be sure
to flex housing outward near the keyless entry mod-
ule until the console snaps onto the rear mounting
bracket.
POWER LOCK/UNLOCK RELAY REMOVE/INSTALL
The power lock/unlock relays are located in the re-
lay center. The relay center is located on the lower
instrument panel trim cover just right of the steering
column (Fig. 19).
(1) Remove the appropriate relay from the relay
center.
(2) Reverse removal procedure to install.
Fig. 19 Power Lock/Unlock Relays
8P - 12 POWER LOCKSJ

DIAGNOSIS
BUZZER MODULE
(1) Check fuses (15 and 17 - XJ, 3 and 9 - YJ) in
the fuseblock module. If fuses are OK, go to next
step. If not OK, replace fuses as required.
(2) Check for battery voltage at fuse (15 - XJ, 3 -
YJ) in fuseblock module. If OK, go to next step. If not
OK, repair feed circuit from power distribution center
as required.
(3) Turn ignition switch to ON position. Check for
battery voltage at fuse (17 - XJ, 9 - YJ) in the fuse-
block module. If OK, go to next step. If not OK, re-
pair feed from ignition switch as required.
(4) Turn ignition switch to OFF position. Replace
buzzer module with a known good unit and test op-
eration. If not OK, remove buzzer module and go to
next step.
(5) Check for battery voltage at cavity for buzzer
terminal 7 in buzzer module connector (Fig. 1). If
OK, go to next step. If not OK, repair circuit to fuse
(15 - XJ, 3 - YJ).
(6) Turn ignition switch to ON position. Check for
battery voltage at cavity for buzzer terminal 1 in
buzzer module connector. If OK, go to next step. If
not OK, repair circuit to fuse (17 - XJ, 9 - YJ) in fuse-
block module.
(7) Turn ignition switch to OFF position. Check for
continuity between cavity for buzzer terminal 3 and
a good ground. There should be continuity. If OK, go
to diagnosis for switch that is related to buzzer mal-
function. If not OK, repair circuit to ground as re-
quired.
DRIVER'S DOOR JAMB SWITCH
(1) Open driver's door and note whether interior
lamps light. They should light. If OK, see diagnosis
for Ignition Key-In Switch (XJ or YJ) or Headlamp
Switch (XJ only). If not OK, go to next step.
(2) Check for continuity between door jamb switch
body and a good ground. There should be continuity.
If OK, go to next step. If not OK, tighten or clean
switch attachment to hinge pillar as required to re-
store ground path.
(3) Remove switch from hinge pillar and check
wire connections for clean and tight engagement. If
OK, replace faulty switch. If not OK, clean and
tighten connections as required.
IGNITION KEY-IN SWITCH
XJ MODELS
(1) Remove steering column shrouds (refer to
Group 8D - Ignition Systems for procedure). Unplug
ignition key-in switch connector from ignition switch
(Fig. 3). Open driver's door. Check for continuity be-
tween cavity 4 (black/light blue wire) and a good
ground. There should be continuity. If OK, go to next
step. If not OK, repair circuit to driver's door jamb
switch as required.
(2) Insert ignition key in ignition lock cylinder.
Check for continuity between key-in switch cavities 3
and 4 (Fig. 4). There should be continuity until key is
removed. If OK, go to next step. If not OK, replace
ignition switch.
(3) Check for continuity between key-in switch har-
ness connector cavity 3 (light blue wire) and cavity
for terminal 6 of buzzer module in buzzer module
connector. There should be continuity. If not OK, re-
pair circuit from switch to buzzer module as re-
quired.
Fig. 1 Buzzer Module Connector
Fig. 2 Buzzer Module Terminals
8U - 2 CHIME/BUZZER WARNING SYSTEMSJ

FUEL/IGNITION
INDEX
page page
Automatic Shut Down (ASD) Relay............. 1
Battery Feed.............................. 1
Brake Switch Input......................... 5
Camshaft Position Sensor.................... 3
CCDBus ................................ 5
Crankshaft Position Sensor................... 3
Data Link Connector........................ 5
Diagram Index Ð2.5L Engine.................. 6
Diagram Index Ð4.0L Engine.................. 6
Engine Coolant Temperature Sensor............ 3
Extended Idle Switch....................... 5
Fuel Injectors............................. 1
Fuel Pump Module......................... 2
Fuel Pump Relay.......................... 2
Heated Oxygen Sensor...................... 3Idle Air Control (IAC) Motor................... 2
Ignition Coil.............................. 2
Ignition Switch............................ 1
Intake Air Temperature Sensor................ 4
Malfunction Indicator Lamp (MIL)............... 5
Manifold Absolute Pressure Sensor............. 4
Park/Neutral Position Switch.................. 4
Power (Device) Ground...................... 5
Power Steering Pressure Switch............... 5
Tachometer Signal......................... 5
Throttle Position Sensor..................... 4
Torque Converter Clutch (TCC) Solenoid and
Relay................................. 4
Upshift Lamp............................. 5
Vehicle Speed Sensor....................... 2
IGNITION SWITCH
Circuit A1 from fuse 11 in the power distribution
center (PDC), supplies battery voltage to the ignition
switch. Depending upon position, the ignition switch
powers circuits A21, A38, A41, or A48.
START POSITION
In the START position, the ignition switch connects
circuit A1 to circuit A41. Circuit A41 connects to the
coil side of the starter motor relay.
Additionally in the START position, the case
grounded ignition switch provides ground for the
brake lamp switch and the warning lamps in the
instrument cluster.
START OR RUN POSITION
In the START or RUN position, the ignition switch
connects circuit A1 to circuit A21. Circuit A21 splices
to power fuse 17 in the fuse block and the coil side of
the Automatic Shut Down (ASD) relay and the fuel
pump relay.
RUN (ONLY) POSITION
When the ignition switch is in the RUN position, it
connects circuit A1 to circuit A38. Circuit A22 splices
to power fuses 1 and 7 in the fuse block.
²Fuse 1 powers the rear wiper system on circuit
V15.
²Fuse 7 feeds the Anti-Lock Brake System (ABS) on
circuit 236.
ACCESSORY OR RUN POSITIONS
In the ACCESSORY or RUN positions, the ignition
switch connects circuit A1 to circuit A48. Circuit A48
connects to a bus bar in the fuse block that feeds
fuses 2, 5, and 8.
AUTOMATIC SHUT DOWN (ASD) RELAY
When the ignition switch is in either the START or
RUN positions, it connects circuit A1 from fuse 6 in
the Power Distribution Center (PDC) to circuit A21.
Circuit A21 supplies battery voltage to the coil side of
the Automatic Shut Down (ASD) relay. The Power-
train Control Module (PCM) provides ground for the
relay on circuit K51. Circuit K51 connects to cavity 51
of the PCM.
When the PCM grounds the ASD relay, contacts
inside the relay close and connect circuit A18 from
fuse 14 in the PDC to circuit A142. Circuit A142
splices to the generator field terminal, fuel injectors,
and ignition coil. Circuit A142 also connects to cavity
57 of the PCM.
HELPFUL INFORMATION
²Along with supplying voltage to the coil side of the
ASD relay, circuit A21 also supplies voltage to the coil
side of the fuel pump relay.
BATTERY FEED
Circuit A14 from fuse 2 in the Power Distribution
Center (PDC) supplies battery voltage to cavity 3 of
the powertrain control module.
HELPFUL INFORMATION
Circuit A14 also supplies power to the contact sides
of the fuel pump relay and fuse F2 in the PDC. Fuse
F2 powers circuit A18 which supplies voltage to the
contact side of the automatic shut down relay.
FUEL INJECTORS
When the Automatic Shut Down (ASD) relay con-
tacts close, they connect circuits A14 and A142. Cir-
J8W-30 FUEL/IGNITIONÐXJ VEHICLES 8W - 30 - 1