height JEEP CHEROKEE 1994 Service User Guide

At the start of antilock braking, pedal height will
decrease as the volume of fluid in the master cylin-
der is used up. When pedal height drops a predeter-
mined amount, the pedal travel sensor will signal
the ECU to run the pump. At this point, the pump is
activated to supply the extra fluid volume and re-
store pedal height at the same time.
The pump does not run continuously. It cycles on/
off according to signals from the travel sensor and
ECU. The pump is connected directly to the mastercylinder reservoir by hoses. During antilock braking,
the additional volume of fluid needed is drawn by the
pump from the reservoir.
WHEEL SPEED SENSOR OPERATION
Wheel speed input signals are generated by a sen-
sor and tone ring at each wheel. The sensors, which
are connected directly to the ECU, are mounted on
brackets attached to the front steering knuckles and
rear brake support plates.
The sensor triggering devices are the tone rings
which are similar in appearance to gears. The tone
rings are located on the outboard end of each front/
rear axle shaft. The speed sensors generate a signal
whenever a tone ring tooth rotates past the sensor
pickup face.
The wheel speed sensors provide the input signal to
the ECU. If input signals indicate ABS mode brak-
ing, the ECU causes the HCU solenoids to decrease,
hold, or increase fluid apply pressure as needed.
The HCU solenoid valves are activated only when
wheel speed input signals indicate that a wheel is
approaching a high slip, or lockup condition. At this
point, the ECU will cycle the appropriate wheel con-
trol channel solenoid valves to prevent slip or lockup.
The wheel sensors provide speed signals whenever
the vehicle wheels are rotating. The ECU examines
these signals for degree of deceleration and wheel
slip. If signals indicate normal braking, the solenoid
valves are not activated. However, when incoming
signals indicate the approach of wheel slip, or lockup,
the ECU cycles the solenoid valves as needed.
ACCELERATION SWITCH OPERATION
The ECU monitors the acceleration switch at all
times. The switch assembly contains three mercury
switches that monitor vehicle ride height and decel-
eration rates (G-force). Sudden, rapid changes in ve-
hicle and wheel deceleration rate, triggers the switch
sending a signal to the ECU. The switch assembly
provides three deceleration rates; two for forward
braking and one for rearward braking.
Fig. 12 Solenoid Valves In Pressure Hold Cycle
Fig. 13 Solenoid Valves In Pressure Increase Cycle
Fig. 14 Pedal Travel Sensor Actuation
JANTILOCK BRAKE SYSTEM OPERATION 5 - 45

POWER SEATS
CONTENTS
page page
DIAGNOSIS............................. 1
GENERAL.............................. 1POWER SEAT MOTOR REPLACEMENT....... 2
SWITCH TESTING....................... 2
GENERAL
The power seat can be adjusted in 6 different direc-
tions (Fig. 1). The control switch is on the lower out-
board side of the seat.
The front lever on the switch raises or lowers (tilts)
the front of the seat cushion. The center lever raises
or lowers the complete seat by moving the switch up
or down. The center lever also moves the seat for-
ward or rearward by moving the switch forward or
rearward. The rear lever raises or lowers (tilts) the
back of the seat cushion.
There are 3 reversible motors that operate the
power seat. The front and rear of the seat are oper-
ated by different motors. They can be raised or low-
ered independently of each other. Moving the center
position seat switch to either the UP or DOWN posi-
tion, runs both the front and rear motors at the same
time.
The forward-rearward motor is operated by the
center position seat switch. When the switch is held
in the FORWARD position, battery voltage is applied
through the switch contacts to pin S3 and the for-ward-rearward motor. The motor is grounded
through pin S4 and the contacts of the back switch to
pin 2 and to ground. The motor runs to drive the seat
forward until the switch is released.
With the switch in the REAR position, pin S4 re-
ceives battery voltage and pin S3 is grounded. This
reversed polarity causes the motor to run in the op-
posite direction and drive the seat backward.
The front motor works in a similar way when the
front height switch is operated.
To raise the entire seat, the center position seat
switch is held in the UP position. This applies bat-
tery voltage to both pins S1 and S5 and the front and
rear motors. Pins S2 and S6 are grounded through
the down switches and the lower switch. Both motors
run to drive the entire seat up. A similar action oc-
curs to move the entire seat down.
Each motor contains a self-resetting circuit breaker
to protect it from overload. Consecutive or frequent
resetting must not be allowed to continue. Make nec-
essary repairs.
DIAGNOSIS
Refer to Group 8W-Wiring Diagrams for a complete
circuit diagram.
Before any testing is attempted the battery should
be fully charged and all connections and pins cleaned
and tightened to insure proper continuity and
grounds.
With the dome light on, apply switch in direction
of the failure. If the dome light dims, the seat may
be jamming. Check for binding. If the dome light
does not dim, then proceed with the following electri-
cal tests.
SEAT MOTOR ASSEMBLY
²Position seat switch to move all 3 seat motors. The
seat should move in all directions. If not, go to No
Seat Motors Operate. If one or more motors operate,
refer to switch testing.
Test seat switch. If OK, replace defective motor.
NO SEAT MOTORS OPERATE
Circuit breaker installed.
²Probe 30 amp circuit breaker, cavity #16 on fuse
panel. If battery voltage is present, replace circuit
breaker.
Fig. 1 Power Seat Switch
JPOWER SEATS 8R - 1

(14) Install the remaining flywheel housing bolts.
Tighten the bolts to 38 Nzm (28 ft. lbs.) torque.
(15) Install the starter motor and connect the ca-
ble. Tighten the bolts to 45 Nzm (33 ft. lbs.) torque.
(16) Install the oil filter.
(17) Lower the vehicle.
(18) Connect the coolant hoses and tighten the
clamps.
(19) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(20) Remove the pulley-to-water pump flange
alignment capscrew and install the fan and spacer or
Tempatrol fan assembly.
(21) Tighten the serpentine drive belt according to
the specifications listed in Group 7, Cooling System.
(22) Install the fan shroud and radiator.
(23) Connect the radiator hoses.
(24) Connect the heater hoses.
(25) Connect the throttle valve rod and retainer.
(26) Connect the throttle cable and install the rod.
(27) Install the throttle valve rod spring.
(28) Connect the speed control cable, if equipped.
(29) Connect the oxygen sensor wire connector.
(30) Install the vacuum hose and check valve on
the brake booster.
(31) Connect the coolant temperature sensor wire
connector.
(32) Connect the idle speed actuator wire connec-
tor.
(33) Connect the fuel inlet and return hoses at the
fuel rail. Verify that the quick-connect fitting assem-
bly fits securely over the fuel lines by giving the fuel
lines a firm tug.
(34) Install the fuel line bracket to the intake
manifold.
(35) Connect all fuel injection wire connections.
(36) Install the engine ground strap.
(37) Connect the ignition coil wire connector.
(38) Remove the coolant temperature sending unit
to permit air to escape from the block. Fill the cool-
ing system with coolant. Install the coolant tempera-
ture sending unit when the system is filled.
(39) Install the battery and connect the battery ca-
bles.
(40) Install the air cleaner bonnet to the throttle
body.
(41) Install the air cleaner.
(42) Lower the hood and secure in place.
(43) Start the engine and inspect for leaks.
(44) Stop the engine and check the fluid levels.
Add fluid, as required.ENGINE CYLINDER HEAD COVER
A cured gasket is part of the engine cylinder head
cover.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect the Crankcase Ventilation (CCV)
vacuum hose from engine cylinder head cover (Fig.
1).
(3) Disconnect the fresh air inlet hose from the en-
gine cylinder head cover (Fig. 1).
(4) Remove the engine cylinder head cover mount-
ing bolts.
(5) Remove the engine cylinder head cover.
CLEANING
Remove any original sealer from the cover sealing
surface of the engine cylinder head and clean the
surface using a fabric cleaner.
Remove all residue from the sealing surface using
a clean, dry cloth.
INSPECTION
Inspect the engine cylinder head cover for cracks.
Replace the cover, if cracked.
The original grey gasket material should NOT be
removed. If sections of the gasket material are miss-
ing or are compressed, replace the engine cylinder
head cover. However, sections with minor damage
such as small cracks, cuts or chips may be repaired
with a hand held applicator. The new material must
be smoothed over to maintain gasket height. Allow
the gasket material to cure prior to engine cylinder
head cover installation.
INSTALLATION
(1) If a replacement cover is installed, transfer the
CCV valve grommet the oil filler cap from the origi-
nal cover to the replacement cover.
(2) Install engine cylinder head cover. Tighten the
mounting bolts to 10 Nzm (85 in. lbs.) torque.
Fig. 1 Engine Cylinder Head Cover
9 - 18 2.5L ENGINEJ

(17) Tighten the serpentine drive belt according to
the specifications listed in Group 7, Cooling System.
(18) Install the fan shroud and radiator (refer to
Group 7, Cooling System for the proper procedure).
(19) Connect the radiator hoses.
(20) Connect the throttle valve rod and retainer.
(21) Connect the throttle cable and install the rod.
(22) Install the throttle valve rod spring.
(23) Connect the speed control cable, if equipped.
(24) Connect the oxygen sensor wire connector.
(25) Install the vacuum hose and check valve on
the brake booster.
(26) Connect the coolant temperature sensor wire
connector.
(27) Connect the idle speed actuator wire connec-
tor.
(28) Connect the fuel inlet and return hoses at the
fuel rail. Verify that the quick-connect fitting assem-
bly fits securely over the fuel lines by giving the fuel
lines a firm tug.
(29) Install the fuel line bracket to the intake
manifold.
(30) Connect all fuel injection wire connections.
(31) Install the engine ground strap.
(32) Connect the ignition coil wire connector.
(33) Remove the coolant temperature sending unit
to permit air to escape from the block. Fill the cool-
ing system with coolant. Install the coolant tempera-
ture sending unit when the system is filled.
(34) If equipped with power steering:
(a) Remove the protective caps
(b) Connect the hoses to the fittings at the steer-
ing gear. Tighten the nut to 52 Nzm (38 ft. lbs.)
torque.
(c) Fill the pump reservoir with fluid.
(35) Install the battery and connect the battery ca-
bles.
(36) Install the air cleaner bonnet to the throttle
body.
(37) Install the air cleaner.
(38) Lower the hood and secure in place.
(39) Start the engine and inspect for leaks.
(40) Stop the engine and check the fluid levels.
Add fluid, as required.
ENGINE CYLINDER HEAD COVER
A cured gasket is part of the engine cylinder head
cover.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Disconnect the Crankcase Ventilation (CCV)
vacuum hose from engine cylinder head cover (Fig.
1).
(3) Disconnect the fresh air inlet hose from the en-
gine cylinder head cover (Fig. 1).
(4) Remove the engine cylinder head cover mount-
ing bolts.(5) Remove the engine cylinder head cover.
CLEANING
Remove any original sealer from the cover sealing
surface of the engine cylinder head and clean the
surface using a fabric cleaner.
Remove all residue from the sealing surface using
a clean, dry cloth.
INSPECTION
Inspect the engine cylinder head cover for cracks.
Replace the cover, if cracked.
The original grey gasket material should NOT be
removed. If sections of the gasket material are miss-
ing or are compressed, replace the engine cylinder
head cover. However, sections with minor damage
such as small cracks, cuts or chips may be repaired
with a hand held applicator. The new material must
be smoothed over to maintain gasket height. Allow
the gasket material to cure prior to engine cylinder
head cover installation.
INSTALLATION
(1) If a replacement cover is installed, transfer the
CCV valve grommet and oil filler cap from the orig-
inal cover to the replacement cover.
(2) Install engine cylinder head cover. Tighten the
mounting bolts to 10 Nzm (85 in. lbs.) torque.
(3) Connect the CCV hoses (Fig. 1).
(4) Connect negative cable to battery.
ROCKER ARMS
This procedure can be done with the engine in or
out of the vehicle.
REMOVAL
(1) Remove the engine cylinder head cover.
(2) Remove the capscrews at each bridge and pivot
assembly (Fig. 2). Alternately loosen the capscrews
one turn at a time to avoid damaging the bridges.
Fig. 1 Engine Cylinder Head Cover
J4.0L ENGINE 9 - 59

INSTALLATION
(1) After the PCM electrical connector has been
separated from the PCM, inspect the pins for corro-
sion, being spread apart, bent or misaligned. Also in-
spect the pin heights in the connector. If the pin
heights are different, this would indicate a pin has
separated from the connector. Repair as necessary.
(2) Install PCM. Tighten three mounting bolts to 1
Nzm (9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting bolt to 4 Nzm (35 in. lbs.) torque.
(4) YJ Models: Install windshield washer fluid
tank.
(5) Connect negative cable to battery.
QUICK-CONNECT FITTINGS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
THROTTLE BODY
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect air cleaner hose from throttle body.
(3) Disconnect idle air control motor and throttle
position sensor wire connectors.
(4) Disconnect accelerator cable, throttle cable (au-
tomatic transmission) and speed control cable (if
equipped) from throttle arm (Fig. 15).
(5) Remove throttle body mounting bolts, throttle
body and gasket. Discard old gasket (Fig. 16).
INSTALLATION
(1) Install throttle body and new gasket. Tighten
throttle body mounting bolts to 12 Nzm (9 ft. lbs.)
torque.
(2) Connect idle air control motor and throttle po-
sition sensor wire connectors.
(3) Connect throttle linkage to throttle arm.CAUTION: When the automatic transmission throttle
cable is connected, it MUST be adjusted.
(4) If equipped with an automatic transmission,
connect and adjust the transmission line pressure ca-
ble. Refer to Group 21, Transmissions for adjustment
procedure.
(5) Install air cleaner hose to throttle body.
(6) Connect negative battery cable to battery.
THROTTLE POSITION SENSOR (TPS)
The TPS is mounted to the throttle body (Figs. 17
or 18).
REMOVAL
(1) Disconnect TPS electrical connector.
(2) Remove TPS mounting bolts.
(3) Remove TPS.
INSTALLATION
The throttle shaft end of the throttle body slides
into a socket in the TPS (Fig. 19). The TPS must be
installed so that it can be rotated a few degrees. (If
Fig. 16 Throttle
BodyÐRemoval/InstallationÐTypical
Fig. 17 TPS LocationÐ2.5L Engine
Fig. 15 Cables at Throttle Body
JFUEL SYSTEM 14 - 59

(8) Check clutch piston stroke length a second
time. If length is OK, continue with assembly. If
stroke length is incorrect, replace clutch discs or use
different thickness clutch pack retainer (Fig. 12). See
Specifications section for retainer thicknesses.
(9) Lubricate clutch drum thrust washer with pe-
troleum jelly and install it in drum (Fig. 3).
(10) Mount direct clutch assembly on forward
clutch assembly and check assembled height (Fig.
14). Height should be 70.3 to 71.5 mm (2.767 to 2.815
in.).
(11) If assembled height is incorrect, clutches are
not seated.(12) If clutch height is OK, remove direct clutch
from forward clutch and proceed to forward clutch
overhaul.
Fig. 11 Installing Direct Clutch Discs And Plates
Fig. 12 Install Clutch Pack Retainer
Fig. 13 Adjusting Clutch Pack Snap Ring Position
Fig. 14 Checking Direct Clutch Assembled Height
21 - 222 AW-4 TRANSMISSION OVERHAULJ

(5) Lubricate and install new O-ring on clutch
drum hub (Fig. 7).
(6) Lubricate and install new O-rings on clutch pis-
ton and install piston in drum.
(7) Install piston return springs.
(8) Compress piston return springs with Tool 7538 and
shop press and install piston snap ring. Be sure snap
ring end gap is not aligned with any notches in drum.
(9) Install cushion plate in drum. Concave side of
plate faces downward (Fig. 5).
(10) Install clutch discs, plates and retainer (Fig. 15). In-
stall tabbed plate followed by disc until required number of
plates and discs are installed. Use six plates and discs.
(11) Install clutch pack snap ring.
(12) Recheck clutch piston stroke length using
same method outlined at beginning of disassembly
procedure. If stroke length is not within specified
limits, replace clutch discs.
(13) Lubricate race and bearing with petroleum jelly
and install them in clutch drum (Fig. 16). Be sure bear-
ing rollers face up and race lip seats in drum as shown.
(14) Verify bearing and race size.
²Outer diameter of bearing is 46.7 mm (1.839 in).
²Outer diameter of race is 48.9 mm (1.925 in.).
²Inner diameter of bearing and race is 26.0 mm
(1.024 in.).
(15) Mount forward clutch on direct clutch and
check assembled height (Fig. 17). Height should be
70.3 - 71.5 mm (2.767 - 2.815 in.).
Fig. 15 Installing Forward Clutch Discs And Plates
Fig. 16 Installing Thrust Bearing And Race
Fig. 17 Checking Forward Clutch Assembled Height
Fig. 14 Installing Clutch Drum Shaft Seal Rings
JAW-4 TRANSMISSION OVERHAUL 21 - 227

(6) Attach the latch release cable to the clips.
(7) Connect the latches to the latch rod and posi-
tion them on the hood.
(8) Install the screws to attach the latches to the
hood.
Tighten the screws to 9 Nzm (77 in-lbs) torque.
(9) Position the safety latch on the hood and install
the attaching nuts. Tighten the screws to 13 Nzm
(115 in-lbs) torque.
(10) Test latch release cable and latches for proper
operation.
(11) Connect the underhood lamp wire harness
connector.
(12) Inspect the hood for proper alignment and ad-
just as necessary.
HOOD ADJUSTMENT
The hood bolt holes are elongated for fore and aft
and side-to-side adjustment.
(1) If hood is low to the cowl panel, insert shims
between the hinge and hood at the rear hinge bolts.
(2) Adjust the hood bumper (Fig. 18) in or out to
provide proper hood-to-fender height alignment.(3) Adjust the hood strikers (Fig. 19) with shims as
necessary. Tighten the screws to 22 Nzm (16 ft-lbs)
torque after adjustment.
(4) Align each latch and striker so that the striker
enters latch squarely.
HOOD HINGE REPLACEMENT
REMOVAL
(1) Remove the hood from the vehicle.
(2) Remove the seal from the hinge base (Fig. 20).
(3) Remove the hinge retaining nuts from the
studs.
(4) Remove the restraint cable and hinge from the
cowl panel.
INSTALLATION
(1) Position the hinge over the studs and place the
restraint cable on the right side, lower stud.
Fig. 17 Hood Insulation Panel
Fig. 18 Hood Bumper
Fig. 19 Hood Latch Striker
Fig. 20 Hood Hinge and Seal
JBODY COMPONENTSÐXJ VEHICLES 23 - 9

FRONT FASCIA AND SKID PLATEÐYJ RENEGADE
VEHICLES
The skid plate and the front fascia can also be
removed independently.
REMOVAL
(1) For convenience, lift the vehicle to a comfort-
able height on a hoist. Support the vehicle.
(2) If necessary, remove the step pad from the fas-
cia (Figs. 46 and 47).
(3) Remove the fascia push pins from the fascia
support and retaining bolts from the skid plate. Re-
move the fascia from the frame crossmember (Fig.
48).
(4) Remove the retaining bolts and the fascia
spacer from the frame crossmember (Fig. 47).
Fig. 46 Front Fascia and Skid Plate
Fig. 47 Front Fascia and Skid PlateÐExploded View
Fig. 48 Front Fascia Removed
Fig. 45 YJ Renegade Front Fender
23 - 148 BODY COMPONENTSÐXJ VEHICLESJ

(5) Remove the retaining screws and the fascia
step pad support bracket from the frame crossmem-
ber (Fig. 47).
(6) Remove the retaining bolts from the skid plate.
Remove the skid plate from the brackets.
(7) Remove the retaining screws from the skid
plate brackets. Remove the brackets from the frame
rails.
(8) Remove the retaining bolts and the fascia sup-
port from the cover plate.
INSTALLATION
(1) Position the fascia support on the cover plate
and install the retaining bolts (Fig. 47). Tighten the
bolts to 5 Nzm (44 in-lbs) torque.
(2) Position the skid plate brackets at the frame
rails and install the retaining screws. Tighten the
screws to 25 Nzm (18 ft-lbs) torque.
(3) Position the skid plate at the brackets and in-
stall the retaining bolts. Tighten the bolts to 25 Nzm
(18 ft-lbs) torque.
(4) Position the fascia step pad support bracket at
the frame crossmember and install the retaining
screws. Tighten the screws to 25 Nzm (18 ft-lbs)
torque.
(5) Position the fascia spacer at the frame cross-
member and install the retaining bolts. Tighten the
nuts to 6 Nzm (53 in-lbs) torque.
(6) Position the fascia at the frame crossmember
and install the retaining bolts and push pins.
Tighten the bolts to 10 Nzm (7 ft-lbs) torque.
(7) Install the step pad on the fascia.
(8) If applicable, remove the support and lower the
vehicle.
FRONT FENDER EXTENSION PANELÐYJ RENEGADE
VEHICLES
REMOVAL
(1) For convenience, lift the vehicle to a comfort-
able height on a hoist. Support the vehicle.
(2) Remove the radio antenna mast from the
fender extension panel.
(3) Remove the hood bumper from the extension
panel.
(4) Remove the fog lamp from the extension panel.
If necessary, refer to the removal procedure.
(5) Detach the hood latch from the hood.
(6) Disconnect the side marker lamp wire harness
bulb socket.
(7) Remove the push pins that attach the fender
extension panel to the support brackets (Fig. 49). Re-
move the panel from the from the front fender.
(8) If necessary, remove the hood latch and the
side marker lamp from the extension panel (Fig. 49).
(9) Remove the retaining bolts and the support/re-
tainer brackets from the front fender (Figs. 49 and
50).
The fender and rocker extension panel sup-
port bracket (Fig. 50) also supports the rocker
extension panel. Before the bracket can be re-
moved, the rocker extension panel must first be
separated from the bracket.
INSTALLATION
(1) If removed, install the hood latch and the side
marker lamp on the extension panel (Fig. 49).
Fig. 49 Front Fender Extension Panel
JBODY COMPONENTSÐXJ VEHICLES 23 - 149