1995 JEEP CHEROKEE steering

SPEED CONTROLÐPCM INPUT
The speed control system provides three separate
inputs to the powertrain control module (PCM); On/
Off, Set and Resume. The On/Off input informs the
PCM that the speed control system has been acti-
vated. The Set input informs the PCM that a fixed
vehicle speed has been selected. The Resume input
indicates to the PCM that the previous fixed speed is
requested.
The speed control operating range is from 50 km/h
to 142 km/h (35 to 85 mph). Inputs that effect speed
control operation are:
²Brake switch position
²Park/neutral switch
²Vehicle speed sensor
²Throttle position sensor
Refer to Group 8H for further speed control infor-
mation.
SENSOR RETURNÐPCM INPUT
Sensor Return provides a low noise ground refer-
ence for all system sensors.
THROTTLE POSITION SENSOR (TPS)ÐPCM INPUT
The throttle position sensor (TPS) is mounted on
the throttle body (Figs. 14 or 15). The TPS is a vari-
able resistor that provides the powertrain control
module (PCM) with an input signal (voltage) that
represents throttle blade position. The sensor is con-
nected to the throttle blade shaft. As the position of
the throttle blade changes, the resistance of the TPS
changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
PCM) represents the throttle blade position. The
PCM receives an input signal voltage from the TPS.
This will vary in an approximate range of from 1 volt
at minimum throttle opening (idle), to 4 volts at wide
open throttle. Along with inputs from other sensors,the PCM uses the TPS input to determine current
engine operating conditions. In response to engine
operating conditions, the PCM will adjust fuel injec-
tor pulse width and ignition timing.
VEHICLE SPEED SENSORÐPCM INPUT
The vehicle speed sensor (Fig. 16) is located in the
extension housing of the transmission (2 wheel drive)
or on the transfer case extension housing (4 wheel
drive). The sensor input is used by the powertrain
control module (PCM) to determine vehicle speed and
distance traveled.
The speed sensor generates 8 pulses per sensor
revolution. These signals, in conjunction with a
closed throttle signal from the throttle position sen-
sor, indicate a closed throttle deceleration to the
PCM. When the vehicle is stopped at idle, a closed
throttle signal is received by the PCM (but a speed
sensor signal is not received).
Under deceleration conditions, the PCM adjusts the
idle air control (IAC) motor to maintain a desired
MAP value. Under idle conditions, the PCM adjusts
the IAC motor to maintain a desired engine speed.
Fig. 13 Power Steering Pump Pressure SwitchÐXJ
Models
Fig. 14 Throttle Position SensorÐ2.5L Engine
Fig. 15 Throttle Position SensorÐ4.0L Engine
JFUEL SYSTEM COMPONENT DESCRIPTION/SYSTEM OPERATION 14 - 25

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

(2) Place a small container or shop towel beneath
the switch to collect any excess fluid.
(3) Remove the switch.
INSTALLATION
(1) Install the power steering switch.
(2) Connect the electrical connector to the switch.
(3) Check power steering fluid and add as neces-
sary.
(4) Start the engine and again check power steer-
ing fluid. Add fluid if necessary.
POWERTRAIN CONTROL MODULE (PCM)
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 19). On YJ
models, the PCM is located in the engine compart-
ment behind the windshield washer fluid reservoir
(Fig. 20).
REMOVAL
(1) Disconnect the negative battery cable at the
battery.(2) YJ Models Only: Remove the windshield
washer fluid tank.
(3) Loosen the 60-Way connector mounting bolt
(Figs. 19 or 20).
(4) Remove the electrical connector by pulling
straight back.
(5) Remove the three PCM mounting bolts.
(6) Remove PCM.
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. 21).
(5) Remove throttle body mounting bolts (Fig. 22),
throttle body and gasket. Discard old gasket.
Fig. 18 Power Steering Pressure SwitchÐXJ Models
Fig. 19 PCM LocationÐXJ Models
Fig. 20 PCM LocationÐYJ Models
14 - 64 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ

STEERING
CONTENTS
page page
GENERAL INFORMATION.................. 1
GENERAL INFORMATION................. 48
MANUAL STEERING GEAR................ 37
POWER STEERING PUMP................. 11
POWER STEERING SYSTEM DIAGNOSIS...... 3
RECIRCULATING BALL POWER STEERING
GEAR............................... 21STEERING COLUMN GENERAL SERVICEÐXJ . 47
STEERING COLUMNÐYJ................. 58
STEERING LINKAGEÐXJ................. 16
STEERING LINKAGEÐYJ................. 19
STEERING RHD......................... 74
TORQUE SPECIFICATIONS................ 78
GENERAL INFORMATION
STEERING SYSTEM COMPONENTS
Jeep vehicles can have either a manual or power
steering system (Fig. 1). A recirculating-ball type
steering gear is used for both systems.
Power steering systems use;
²Steering gear
²Pressure and return fluid hoses and fittings
²Belt driven steering pump
²Integral or remote body mounted pump reservoir
POWER STEERING GEAR
The steering gear is mounted on the left frame rail.
The gear is joined to the intermediate shaft by a uni-
versal joint coupling. The coupling helps isolate noise
and road shock from the interior.
The major internal components of the gear are the:
²Rotary valve assembly
²Steering worm shaft
²Rack piston assembly
²Pitman shaftThe movement of these parts, while turning or
parking, is aided by hydraulic pressure and flow sup-
plied by the pump. Manual steering is always avail-
able at times when the engine is not running or in
the event of pump or belt failure. Steering effort is
higher under such conditions.
The steering stub shaft, rotary valve, worm shaft,
and rack piston assembly are all in line. The oil pas-
sages are internal within the gear housing except for
pressure and return hoses between the gear and
pump.
The power steering gear has a recirculating ball
system. This acts as a rolling thread between the
worm shaft and rack piston. The worm shaft is sup-
ported by a thrust bearing at the lower end and a
bearing assembly at the upper end. When the worm
shaft is turned right, the rack piston moves up in
gear. Turning the worm shaft left moves the rack pis-
ton down in gear. The rack piston teeth mesh with
the sector, which is part of the pitman shaft. Turning
the worm shaft turns the pitman shaft, which turns
the wheels through the steering linkage.
The control valve in the steering gear directs the
power steering fluid to either side of the rack piston.
The rack piston is assisted by hydraulic pressure. If
the steering system loses hydraulic pressure, the ve-
hicle can be controlled manually, but with higher
steering effort.
An identification code located on the side cover des-
ignates the gear ratio (Fig. 2).
²Code BH designates 14:1 ratio used in XJ vehicles
²Code BF designates 13-16:1 ratio used in YJ vehi-
cles
A recirculating-ball steering gear is used with the
power (assisted) steering system (Fig. 1). The power
steering gear can be adjusted and internally serviced.
Fig. 1 Steering Gears
JSTEERING 19 - 1

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

POWER STEERING SYSTEM DIAGNOSIS
PUMP PRESSURE TEST
(1) Check belt tension and adjust as necessary.
(2) Disconnect high pressure hose at gear or pump.
Use a container for dripping fluid.
(3) Connect Gauge 7617 to both hoses using
adapter fitting (Fig. 1). Connect spare pressure hose
to gear or pump.
(4) Open the test valve completely.
(5) Start engine and let idle.
(6) Check fluid level, add fluid as necessary.
(7) Gauge should read below 862 kPa (125 psi), if
above, inspect the hoses for restrictions and repair as
necessary. The initial pressure should be in the range
of 345-552 kPa (50-80 psi).CAUTION: The following test procedure involves
testing maximum pump pressure output and flow
control valve operation. Do not leave valve closed
for more than 5 seconds as the pump could be
damaged.
(8) Close valve fully three times and record highest
pressure indicated each time.All three readings
must be above specifications and within 345
kPa (50 psi) of each other.
²Pressures above specifications but not within 345
kPa (50 psi) of each other, replace pump.
²Pressures within 345 kPa (50 psi) of each other
but below specifications, replace pump.
CAUTION: Do not force the pump to operate against
the stops for more than 2 to 4 seconds at a time.
Pump damage will result.
(9) Open the test valve, turn steering wheel ex-
treme left and right positions against the stops.
Record the highest indicated pressure at each posi-
tion. Compare readings to specifications. If highest
output pressures are not the same against either
stop, the gear is leaking internally and must be re-
paired.
Fig. 1 Pressure Test Gauge
PUMP OPERATING SPECIFICATIONS
JSTEERING 19 - 3

POWER STEERING SYSTEM DIAGNOSIS
19 - 4 STEERINGJ