1995 JEEP YJ ABS

Test the resistance of the wire harness. Do this be-
tween the powertrain control module (PCM) wire
harness connector terminal-2 and the sensor connec-
tor terminal. Also test terminal-4 to the sensor con-
nector terminal. Repair the wire harness as
necessary if the resistance is greater than 1 ohm.
FUEL PUMP RELAY TESTING
For testing this relay, refer to RelaysÐOperation/
Testing in this section of the group.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
TEST
To perform a complete test of the MAP sensor and
its circuitry, refer to DRB scan tool and appropriate
Powertrain Diagnostics Procedures manual. To test
the sensor only, refer to the following:
Inspect the MAP sensor vacuum hose connections
at the throttle body and sensor. Repair as necessary.
CAUTION: When testing, do not remove the electri-
cal connector from MAP sensor (Fig. 36). Be sure
that the MAP sensor harness wires are not dam-
aged by the test meter probes.
Test the MAP sensor output voltage at the MAP
sensor connector between terminals A and B (as
marked on the sensor body) (Fig. 37). With the igni-
tion switch ON and the engine OFF, output voltage
should be 4-to-5 volts. The voltage should drop to 1.5-
to-2.1 volts with a neutral-hot idle speed condition.
Test the powertrain control module (PCM) (termi-
nal-5) for the same voltage described above to verify
the wire harness condition. Repair as necessary.
Test MAP sensor supply voltage at sensor connec-
tor between terminals A and C (Fig. 37) with the ig-
nition ON and engine OFF. The voltage should be
approximately 5 volts (60.5V). Five volts (60.5V)should also be at terminal-6 of the PCM wire harness
connector. Repair or replace the wire harness as nec-
essary.
Test the MAP sensor ground circuit at sensor con-
nector terminal-A (Fig. 37) and PCM connector termi-
nal-4. Repair the wire harness if necessary.
Test the MAP sensor ground circuit at the PCM
connector between terminal-4 and terminal-11 with
an ohmmeter. If the ohmmeter indicates an open cir-
cuit, inspect for a defective sensor ground connection.
Refer to Group 8W, Wiring for location of engine
grounds. If the ground connection is good, replace the
PCM. If terminal-4 has a short circuit to 12 volts,
correct this condition before replacing the PCM.
CRANKSHAFT POSITION SENSOR TEST
Refer to Group 8D, Ignition Systems for test proce-
dures.
Fig. 35 Air Temperature SensorÐ4.0L EngineFig. 36 MAP SensorÐTypical
Fig. 37 MAP Sensor Connector TerminalsÐTypical
JFUEL SYSTEM GENERAL DIAGNOSIS 14 - 47

MULTI-PORT FUEL INJECTION (MFI)ÐCOMPONENT REMOVAL/INSTALLATION
INDEX
page page
Accelerator Pedal and Throttle Cable........... 58
Air Cleaner Element....................... 59
Air Cleaner Housing....................... 58
Air Conditioning (A/C) Clutch Relay............ 58
Automatic Shutdown (ASD) Relay............. 59
Brake Switch............................ 59
Camshaft Position Sensor................... 60
Crankshaft Position Sensor.................. 60
Engine Coolant Temperature Sensor........... 60
Fuel Filter............................... 60
Fuel Injector............................. 60
Fuel Pressure Regulator.................... 61
Fuel Pump Module........................ 61
Fuel Pump Relay......................... 61
Fuel Rail Assembly........................ 62
Fuel System Pressure Release Procedure....... 62
Fuel Tank Pressure Relief/Rollover Valve........ 62Fuel Tanks.............................. 62
Fuel Tubes/Lines/Hoses and Clamps........... 62
Idle Air Control (IAC) Motor.................. 62
Ignition Coil............................. 62
Intake Manifold........................... 63
Intake Manifold Air Temperature Sensor......... 60
Manifold Absolute Pressure (Map) Sensor....... 63
Oxygen (O2S) Sensor...................... 63
Park Neutral Switch....................... 63
Power Steering Pressure SwitchÐ2.5L
Engine Only............................ 63
Powertrain Control Module (PCM)............. 64
Quick-Connect Fittings..................... 64
Throttle Body............................ 64
Throttle Position Sensor (TPS)............... 65
Torque Converter Clutch Relay............... 65
Vehicle Speed Sensor...................... 66
ACCELERATOR PEDAL AND THROTTLE CABLE
Refer to the Accelerator Pedal and Throttle Cable
section of this group for removal/installation proce-
dures.
AIR CONDITIONING (A/C) CLUTCH RELAY
The A/C clutch relay is located in the power distri-
bution center (PDC) (Figs. 1 or 2). For location of this
relay within the PDC, refer to label on PDC cover.
AIR CLEANER HOUSING
REMOVAL
(1) Unlock clean air hose clamp (Figs. 3 or 4) at air
cleaner cover. To unlock the clamp, attach adjustablepliers to clamp and rotate pliers as shown in figure
5. Remove clean air hose at cover.
(2) Disconnect vacuum lines at air cleaner housing.
(3) YJ Models: Release the three over-center type
clamps securing the housing to the housing bracket.
XJ Models: Remove the housing cover and remove air
cleaner element. Remove two bolts and one nut.
(4) Release the air cleaner housing from the ambi-
ent air inlet and remove housing from vehicle.
INSTALLATION
(1) Position air cleaner housing to body and ambi-
ent air inlet.
(2) YJ Models: Lock the three over-center type
clamps securing the housing to the housing bracket.
XJ Models: Install two bolts and one nut to housing.
Install air cleaner element and cover.
(3) Install vacuum lines to housing.
Fig. 1 PDCÐYJ Models
Fig. 2 PDCÐXJ Models
14 - 58 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ

INTAKE MANIFOLD
Refer to Group 11, Exhaust System and Intake
Manifold for removal/installation procedures.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The MAP sensor is located on the dash panel near
the rear of the engine cylinder head (valve) cover
(Fig. 15).
REMOVAL
(1) Disconnect the MAP sensor electrical connector
(Fig. 15).
(2) Disconnect the MAP sensor vacuum supply
hose (Fig. 15).
(3) Remove the MAP sensor mounting bolts and re-
move MAP sensor.
INSTALLATION
(1) Install MAP sensor to dash panel and secure
with mounting bolts.
(2) Install the MAP sensor vacuum supply hose.
(3) Connect the MAP sensor electrical connector.
OXYGEN (O2S) SENSOR
The O2S sensor is installed in the exhaust down
pipe just below the exhaust manifold flange (Fig. 16).
REMOVAL
WARNING: THE EXHAUST MANIFOLD BECOMES
VERY HOT DURING ENGINE OPERATION. ALLOW
ENGINE TO COOL BEFORE REMOVING OXYGEN
SENSOR.
(1) Raise and support the vehicle.
(2) Separate the electrical connectors.
(3) Remove the O2S sensor from the exhaust man-
ifold. Snap-On oxygen sensor wrench (number YA
8875) may be used for removal and installation.
INSTALLATION
Threads of new factory oxygen sensors are coated
with anti-seize compound to aid in removal.
(1) Install the O2S sensor into the exhaust mani-
fold and tighten to 30 Nzm (22 ft. lbs.) torque.
(2) Connect the O2S sensor wire connector to the
main harness.
(3) Lower the vehicle.
PARK NEUTRAL SWITCH
Refer to Group 21, Transmissions for park neutral
switch service.
POWER STEERING PRESSURE SWITCHÐ2.5L
ENGINE ONLY
The power steering pressure switch is installed in
the power steering high-pressure hose (Figs. 17 or
18).
REMOVAL
(1) Disconnect the electrical connector from the
power steering pressure switch.
Fig. 15 MAP SensorÐTypical
Fig. 16 Oxygen SensorÐTypical
Fig. 17 Power Steering Pressure SwitchÐYJ Models
JFUEL SYSTEM COMPONENT REMOVAL/INSTALLATION 14 - 63

POWER STEERING PUMP
Hydraulic pressure is provided for operation of the
power steering gear by a belt driven power steering
pump. The power steering pump is a constant flow
rate and displacement, vane-type pump. The internal
parts in the housing operate submerged in fluid. The
flow control orifice is part of the high pressure line
fitting. The pressure relief valve inside the flow con-
trol valve limits the pump pressure.
Power steering pumps have different pres-
sure rates and are not interchangeable with
other pumps.
The power steering pump is connected to the steer-
ing gear via high pressure and return hose. The
pump shaft has a pressed-on drive pulley that is belt
driven by the crankshaft pulley (Fig. 3).
XJ vehicles with 2.5L engines and all YJ vehicles:
The reservoir is mounted at the front left side of the
engine compartment. XJ vehicles equipped with a
4.0L engine have the reservoir attached to the pump
body with spring clips.
STEERING COLUMNS
Two general types of steering columns are installed
on Jeep vehicles: a fixed, non-tilt column and a tilt
column (Fig. 4).
The ignition key/lock cylinder is located in the
steering column. When the key/lock cylinder is
turned to the LOCK position, the ignition switch and
steering shaft cannot be operated. For vehicles withan automatic transmission, the lock mechanism also
prevents operation of the gear shift mechanism.
The center, slip-type intermediate shaft is attached
to the steering gear and steering column shaft with
universal joints.
Both types of steering columns have anti-theft pro-
visions. They are energy-absorbing.
Fig. 2 Ratio Code Location
Fig. 3 TC Series Pump With Integral Reservoir
Fig. 4 Steering Columns
19 - 2 STEERINGJ

PITMAN SHAFT AND SIDE COVER REPLACEMENT
REMOVE
(1) Remove steering gear from vehicle. Refer to
Power Steering Gear Replacement in this section.
(2) Remove pitman arm from steering gear. Refer
to Pitman Arm Removal in the Steering Linkage sec-
tion.
(3) Rotate stub shaft back and forth to drain power
steering fluid.
DISASSEMBLE
²Clean exposed end of pitman shaft and housing.
²Clean pitman shaft spline with a wire brush.
(1) Remove preload adjuster nut.
(2) Rotate stub shaft with socket to center gear.
Remove side cover bolts.
(3) Remove side cover, gasket and pitman shaft as
an assembly.
(4) Remove pitman shaft from the side cover (Fig.
15).
ASSEMBLE
(1) Install pitman shaft to side cover by screwing
shaft in until it fully seats to side cover.
(2) Install preload adjuster nut.Do not tighten
nut until after pitman shaft adjustment has
been made.(3) Install gasket to side cover and bend tabs
around edges of side cover.
(4) Install pitman shaft assembly and side cover to
housing.
(5) Install side cover bolts and tighten to 60 Nzm
(44 ft. lbs.).
(6) Adjust pitman shaft, refer to Over-Center Ad-
justment.
INSTALL
(1) Install steering gear. Refer to Power Steering
Gear Replacement in this section.
(2) Install pitman arm onto steering gear. Refer to
Steering Linkage in this Group.
HOUSING END PLUG
REMOVE
(1) Remove steering gear from vehicle. Refer to
Power Steering Gear Replacement in this section.
(2) Remove pitman arm from steering gear. Refer
to Steering Linkage in this Group.
(3) Rotate stub shaft back and forth to drain power
steering fluid.
DISASSEMBLE
²Rotate stub shaft back and forth to drain fluid
(1) Rotate retaining ring until one end is under the
hole in the housing. Unseat and force ring from
groove (Fig. 16).
(2) Rotate stub shaft slowly COUNTER-CLOCK-
WISE to remove end plug out from housing (Fig. 17).
Fig. 15 Side Cover and Pitman Shaft
Fig. 16 End Plug Retaining Ring
19 - 28 STEERINGJ

(2) Disconnect the battery negative (ground) cable
and isolate.
(3) Disarm the airbag (refer to group 8M, Electri-
cal for proper and safe procedures).
(4) Remove the air bag module and speed control
switch (if equipped) and disconnect the wire feeds
(Fig. 6).
(5) Disconnect the wire feed to the horn buttons.(6) Remove the steering wheel retaining nut. Score
or paint alignment marks on the column shaft and
steering wheel (if none exist) for installation refer-
ence.
(7) Remove the steering wheel with a universal
puller (Fig. 7).Do not hammer or jolt the steer-
ing column or shaft during removal of the
wheel.
INSTALLATION
(1) Install the steering wheel on column with the
scored marks or master splines aligned. Ensure the
wheel compresses the 2 lock tabs on the clockspring.
(2) Pull the speed control wires through the lower,
larger hole in the steering wheel. Pull the horn wire
through the smaller hole at the top.
(3) Install the retaining nut and tighten to 61 Nzm
(45 ft. lbs.) torque.Force the steering wheel down
on the shaft with the retaining nut only. Do not
hammer or shock the column with sudden im-
pact to install the wheel.
(4) Connect the wire feed to the horn buttons.
(5) Connect the wire feeds to the speed control
switch (Fig. 6). Tighten the air bag module nuts to 9
to 11 Nzm (80 to 100 in. lbs.) torque.
Fig. 5 Airbag Module Remove/Install
Fig. 6 Air Bag Module and Speed Control
19 - 50 STEERINGJ

CLOCKSPRING
WARNING: BEFORE SERVICING AIR BAG SYSTEM,
REMOVE AND ISOLATE BATTERY NEGATIVE (-) CA-
BLE (GROUND) FROM VEHICLE BATTERY. WHEN
AN UNDEPLOYED AIR BAG ASSEMBLY IS TO BE
REMOVED FROM THE STEERING WHEEL, DISCON-
NECT THE BATTERY GROUND CABLE AND ISO-
LATE.
REMOVAL
(1) Place the front wheels in the straight ahead po-
sition before starting the repair.
(2) Disconnect battery negative cable and isolate.
(3) Remove the steering wheel and air bag, refer to
Steering Wheel Removal.
(4) Remove upper and lower steering column
shrouds to gain access to the clockspring wiring (Fig.
8).
(5) Release wire connector at clockspring.
(6) Pull clockspring assembly from column by lift-
ing locking fingers as necessary. The clockspring can-
not be repaired, and must be replaced if faulty.
INSTALLATION
(1) Snap clockspring assembly onto column. If
clockspring is not properly positioned, follow the cen-
tering procedures before installing steering wheel.
(2) Connect the wire connector to the clockspring.
(3) Install upper and lower steering column
shrouds. Be sure wiring is inside of shrouds and not
pinched.
(4) Install the steering wheel and air bag module,
refer to Steering Wheel Installation.
CENTERING PROCEDURE
If the rotating tape within the clockspring is not
positioned properly, the clockspring may fail during
use. The following procedures MUST BE USED to
center the clockspring;
²If it is not known to be properly positioned
²If the front wheels were moved from the straight
ahead position
(1) Place the front wheels in the straight ahead po-
sition before starting the procedure.
(2) Depress the 2 locking tabs to disengage the
locking mechanism (Fig. 9).
(3) Keeping the mechanism disengaged, rotate the
clockspring rotor in the CLOCKWISE DIRECTION
to the end of the travel. Do not apply excessive
torque.
Fig. 7 Steering Wheel Removal
Fig. 8 Upper and Lower Steering Column Shroud
Fig. 9 ClockspringÐAuto-Locking
JSTEERING 19 - 51

(20) Remove the key warning buzzer switch and
contacts as a unit (Fig. 5). Use needle-nose pliers or
a paper clip bent at a right angle (90 degrees).
(21) Turn ignition key/lock cylinder to the ON po-
sition. Insert a thin screwdriver into the slot adjacent
to the switch attaching screw boss (right-hand slot).
Depress the spring latch located at the bottom of the
slot to release the key/lock cylinder. Remove the cyl-
inder (Fig. 6).
(22) Remove the ignition switch and dimmer switch
(Fig. 7) from the lower end of the steering column.
(23) Remove the screws that attach the key/lock
cylinder housing cover to the steering column jacket.
Remove the cover.
(24) Remove the upper bearing race and the bear-
ing seat from the steering shaft (Fig. 8).
(25) Install the tilt-release lever and place the
steering column in the full upward tilt position.
WARNING: THE TILT SPRING GUIDE RETAINER RE-
TAINS STRONG SPRING FORCE.
(26) Press the tilt spring guide retainer inward.
Turn it counterclockwise until the tabs disengage
from the key/lock cylinder housing lugs. Ensure that
the screwdriver blade properly fits the retainer slot.
Remove the tilt spring guide retainer, the guide and
the spring from the housing (Fig. 9).
Fig. 3 Turn Signal Switch Wire Harness Connector
Fig. 4 Turn Signal Switch Removal
Fig. 5 Key Warning Buzzer/Contacts Removal
Fig. 6 Key/lock Cylinder Removal
JSTEERING 19 - 67