ignition JEEP CHEROKEE 1995 Service Repair Manual

DIAGNOSTIC TROUBLE CODE DESCRIPTIONSÐCONTINUED
Diagnostic
Trouble CodeDRB Scan Tool Description of Diagnostic Trouble Code
44* Battery Temp Sensor Volts out of Limit An open or shorted condition exists in the en-
gine coolant temperature sensor circuit or a
problem exists in the PCM's battery tempera-
ture voltage circuit.
46** Charging System Voltage Too High Battery voltage sense input above target
charging voltage during engine operation.
47** Charging System Voltage Too Low Battery voltage sense input below target
charging during engine operation. Also, no sig-
nificant change detected in battery voltage
during active test of generator output.
51** O2S Signal Stays Below Center (Lean) Oxygen sensor signal input indicates lean air/
fuel ratio condition during engine operation.
52** O2S Signal Stays Above Center (Rich) Oxygen sensor signal input indicates rich air/
fuel ratio condition during engine operation.
53* Internal PCM Failure PCM Internal fault condition detected.
or
PCM Failure SRI Communications PCM Internal fault condition detected.
54* No Cam Sync Signal at PCM No fuel sync (camshaft signal) detected during
engine cranking.
55* Display not shown on DRB scan tool Completion of diagnostic trouble code display
on the Malfunction Indicator Lamp (Check En-
gine Lamp).
62* PCM Failure SRI miles not stored Unsuccessful attempt to update SRI (service
reminder indicator) miles in the PCM EE-
PROM.
63* PCM Failure EEPROM Write Denied Unsuccessful attempt to write to an EEPROM
location by the PCM.
* Check Engine Lamp will not illuminate at all times if this Diagnostic Trouble Code was recorded. Cycle
Ignition key as described in manual and observe code flashed by Check Engine lamp.
** Check Engine Lamp will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
JFUEL SYSTEM GENERAL DIAGNOSIS 14 - 57

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

CAMSHAFT POSITION SENSOR
For removal/installation procedures, refer to Group
8D, Ignition System. See Camshaft Position Sensor.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
The intake manifold air temperature sensor is in-
stalled into the intake manifold plenum (Figs. 7 or
8).
REMOVAL
(1) Disconnect the electrical connector from the
sensor.
(2) Remove the sensor from the intake manifold.
INSTALLATION
(1) Install the sensor into the intake manifold.
Tighten the sensor to 28 Nzm (20 ft. lbs.) torque.
(2) Connect the electrical connector to the sensor.
CRANKSHAFT POSITION SENSOR
For description, operation and removal/installation
procedures, refer to Group 8D, Ignition Systems in
this manual.
ENGINE COOLANT TEMPERATURE SENSOR
The coolant temperature sensor is installed in the
thermostat housing (Fig. 9).
REMOVAL
(1) Drain cooling system until the coolant level is
below the cylinder head. Observe theWARNINGSin
Group 7, Cooling.
(2) Disconnect the coolant temperature sensor wire
connector.
(3) Remove the sensor from the thermostat hous-
ing (Fig. 9).
INSTALLATION
(1) Install coolant temperature sensor into the cyl-
inder block. Tighten to 28 Nzm (21 ft. lbs.) torque.
(2) Connect the wire connector.
(3) Fill the cooling system. Refer to Group 7, Cool-
ing System.
FUEL FILTER
Refer to the Fuel Delivery System section of this
group for removal/installation procedures.
FUEL INJECTOR
REMOVAL
(1) Remove the fuel rail. Refer to Fuel Rail Re-
moval in this section.
(2) Remove the clip(s) that retain the fuel injec-
tor(s) to the fuel rail (Figs. 10 or 11).
INSTALLATION
(1) Install the fuel injector(s) into the fuel rail as-
sembly and install retaining clip(s).
(2) If the same injector(s) is being reinstalled, in-
stall new o-ring(s).
(3) Install fuel rail. Refer to Fuel Rail Installation
in this section.
(4) Start engine and check for fuel leaks.
Fig. 7 Sensor LocationÐ2.5L Engine
Fig. 8 Sensor LocationÐ4.0L Engine
Fig. 9 Engine Coolant Temperature SensorÐTypical
14 - 60 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ

FUEL RAIL ASSEMBLY
REMOVAL
WARNING: THE FUEL SYSTEM IS UNDER CON-
STANT FUEL PRESSURE (EVEN WITH THE ENGINE
OFF) OF APPROXIMATELY 131-269 KPA (19-39 PSI).
THIS PRESSURE MUST BE RELEASED BEFORE
SERVICING THE FUEL RAIL.
(1) Remove fuel tank filler tube cap.
(2) Disconnect the negative battery cable from bat-
tery.
(3) Perform the Fuel System Pressure Release Pro-
cedure as described in the Fuel Delivery System sec-
tion of this Group.
(4) Remove and numerically attach a tag (if fuel
injector is not already tagged), the injector harness
connectors. Do this at each injector (Fig. 12).
(5) Disconnect vacuum line from fuel pressure reg-
ulator (Fig. 12).
(6) Disconnect fuel supply line from fuel rail and
the fuel return line from fuel pressure regulator (Fig.
12). Refer to Fuel Tubes/Lines/Hoses and Clamps, or
Quick-Connect Fittings. These can both be found in
the Fuel Delivery section of this group.
(7) Remove fuel rail mounting bolts.
On models with automatic transmissions, it may be
necessary to remove automatic transmission throttle
line pressure cable and bracket. This will aid in fuel
rail assembly removal.
(8) Remove fuel rail by gently rocking until all the
fuel injectors are out of the intake manifold.
INSTALLATION
(1) Position tips of all fuel injectors into the corre-
sponding injector bore in the intake manifold. Seat
injectors into manifold.
(2) Tighten fuel rail mounting bolts to 27 Nzm (20
ft. lbs.) torque.
(3) Connect injector harness connectors to appro-
priate (tagged) injector.
(4) Connect both fuel lines to fuel rail. Refer to the
Fuel Delivery section of this group for procedures.
(5) Connect vacuum supply line to fuel pressure
regulator.
(6) Install protective cap to pressure test port fit-
ting.
(7) Install fuel tank cap.
(8) Connect negative battery cable to battery.
(9) Start engine and check for fuel leaks.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
WARNING: THE FUEL SYSTEM IS UNDER A CON-
STANT PRESSURE (EVEN WITH THE ENGINE OFF)
OF APPROXIMATELY 100 KPA (14.5 PSI). BEFORE
SERVICING THE FUEL PUMP, FUEL RAIL, FUELLINES, FUEL FILTER OR FUEL INJECTOR, THE
FUEL SYSTEM PRESSURE MUST BE RELEASED.
Refer to the Fuel Delivery System section of this
group. See Fuel Pressure Release procedure.
FUEL TANKS
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TANK PRESSURE RELIEF/ROLLOVER VALVE
Refer to the Fuel Tank section of this group for re-
moval/installation procedures.
FUEL TUBES/LINES/HOSES AND CLAMPS
Refer to the Fuel Delivery System section of this
group for removal/installation procedures. Also refer
to Quick-Connect Fittings in the Fuel Delivery sec-
tion of this group.
IDLE AIR CONTROL (IAC) MOTOR
The IAC motor is mounted to the throttle body ad-
jacent to the throttle position sensor (Fig. 14).
REMOVAL
(1) Disconnect the electrical connector from the
IAC motor.
(2) Remove IAC motor torx head mounting bolts.
(3) Remove IAC motor.
INSTALLATION
(1) Install IAC motor into throttle body and
tighten retaining bolts.
(2) Connect electrical connector to IAC motor.
IGNITION COIL
Refer to Group 8D, Ignition Systems for removal/
installation procedures.
Fig. 14 Idle Air Control MotorÐRemoval/
InstallationÐTypical
14 - 62 FUEL SYSTEM COMPONENT REMOVAL/INSTALLATIONJ

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

(4) From the end of travel, rotate the rotor 2 1/2
full turns in the COUNTER CLOCKWISE direction.
The horn wire should end up at the top and the
squib wire at the bottom (Fig. 9).
(5) Install the steering wheel and air bag module,
refer to Steering Wheel Installation.
COLUMN ASSEMBLY REPLACEMENT
CAUTION: Bumping, jolting and hammering on the
steering column shaft and gear shift tube must be
avoided during all service procedures.
REMOVAL
(1) Make sure the front wheels are in thestraight
aheadposition.
(2) Observe Cautions and disconnect the negative
(ground) cable from the battery.
(3) Disarm airbag, refer to Arming/Disarming Air-
bag in this section.
(4) Remove column coupler upper pinch bolt (Fig.
10).
(5) Remove steering wheel and airbag from col-
umn, refer to Steering Wheel-Removal and observe
Cautions/Warnings.
(6) Remove the knee blocker (Fig. 11).
(7) Remove relay box.
(8) Remove tilt lever (if equipped) from column.
(9) Remove the upper and lower steering column
shrouds (Fig. 8).
(10) Remove both pencil braces (fig. 12).
(11) Loosen the panel bracket nuts/studs to allow
the column to drop.
(12) Remove wiring harness connector (Fig. 15)
from the multi function switch.Note: Wiring har-
ness connector is retained to multi function
switch, using an attaching bolt with a 7mm hex
head. access to bolt is through rear of wiring
harness connector.(13) Remove the wiring harness from steering col-
umn (Fig. 16).
Fig. 10 Column Coupler Shaft
Fig. 11 Knee Blocker
Fig. 12 Steering Column Pencil Braces
Fig. 13 Clock Spring And Ignition Switch Wiring
Connections
19 - 52 STEERINGJ

(14) Remove the Interlock cable from the steering
column. Refer to Automatic Transmission Shifter/Ig-
nition Interlock in this group.
(15) Remove the column. Use care to avoid damag-
ing the paint or trim.
INSTALLATION
CAUTION: Bumping, jolting and hammering on the
steering column shaft and gear shift tube must be
avoided during all service procedures.
(1) With the front wheels in the straight ahead po-
sition. Align and install the column to coupler.Do
not apply force at the top of the steering col-
umn shaft.(2) Ensure the ground clip is on the left spacer slot
(Fig. 17).
(3) Install the Interlock cable from the steering col-
umn. Refer to Automatic Transmission Shifter/Igni-
tion Interlock in this group.
(4) Install wiring harness connections to steering
column (Fig. 16).Ensure the wiring is not pinched
and all connections are correctly locked in
place.
(5) Install wiring harness connector onto multi
function switch (Fig. 18). Torque multi function
switch wiring harness connector retaining bolt to 2
Nzm (17 in. lbs.).
(6) Install wiring harness connector for key light
switch connection, onto the ignition switch (Fig. 19).
Fig. 15 Multi Function Switch Wiring Connection
Fig. 16 Steering Column Wiring Harness
J9519-57
Fig. 14 Halo Light And Key In Buzzer Wiring
Connection
JSTEERING 19 - 53

(7) Install wiring harness connectors onto clock
spring and ignition switch assembly (Fig. 20).
(8) Install shaft coupler pinch bolt loose, load col-
umn up to panel bracket.(9) Be sure both spacers are fully seated in the col-
umn support bracket. Tighten the column panel
bracket support nuts to 12 Nzm (105 in. lbs.) torque.
(10) Tighten the coupler pinch bolt to 47 Nzm (35
ft. lbs.) torque.
(11) Install the upper and lower shrouds. Install
the tilt lever (if equipped).
(12) Install rely box.
(13) Install the knee blocker.
(14) Install the steering wheel, refer to Steering
Wheel Installation and observe cautions.
(15) Remove the column shaft shipping lock pin
(installed in service column).
(16) Arm airbag, refer to Arming/Disarming Airbag
in this section.
(17) Connect the battery ground (negative) cable.
COLUMN COMPONENT SERVICE
The Acustar columns have been designed to be ser-
viced as an assembly; less wiring, switches, shrouds,
steering wheel, etc. Also most steering column com-
ponents can be serviced without removing the col-
umn from the vehicle. For additional information on
electrical components refer to Group 8, Electrical.
IGNITION SWITCH SERVICE
TEST AND REPAIR
If the ignition switch effort seems to be excessive
due to binding. Follow the procedure outlined below
to determine the cause.
When service procedures are performed on the
Acustar steering column there are certain areas of
the column that can not be tampered with. If a prob-
lem related to these areas of the steering column are
detected. The entire steering column (less the remov-
able components) should be replaced see (Fig. 1 and
2).
Fig. 17 Ground Clip & Spacer Installation
Fig. 18 Multi Function Switch Wiring Harness
Connector Installed
Fig. 19 Wiring Harness Connection For Key Light
Switch
Fig. 20 Wiring Harness Connection To Clock Spring
And Ignition Switch
19 - 54 STEERINGJ

(1) Remove the ignition switch from the steering
column. Refer toGroup 8D Ignition System.
(2) Using a key cylinder, check the turning effort of
the switch.
²If the ignition switch binds look for the following
conditions.
(1) Look for rough areas or flash in the casting and
if found remove with a file (Fig. 2).
(2) Remove the link and slider.
(3) Check the link to see if it has been bent and if
so replace with a new part.
Put the slider in its slot in the sleeve and verify a
loose fit over the length of the slot. If the slider binds
in the slot at any point lightly file the slider until
clearance is achieved.
²If no binding is found.
Lightly file the ramp on the ignition switch, (The
ramp fits into the casting) until binding no longer oc-
curs.
AUTOMATIC TRANSMISSION SHIFTER/IGNITION
INTERLOCK MECHANISM
The automatic transmission Shifter/Ignition Inter-
lock, is a cable operated system. It interconnects the
automatic transmission floor mounted shifter to the
steering column ignition switch (Fig. 1). The system
locks the shifter into the PARK position. The Inter-
lock system is engaged whenever the ignition switch
is in the LOCK or ACCESSORY position. When the
key is in the OFF or RUN position the shifter is un-
locked and will move into any position. The interlock
system also prevents the ignition switch from being
turned to the LOCK or ACCESSORY position (Fig.
2). Unless the shifter is fully locked into the PARK
position.
INTERLOCK CABLE REPLACEMENT
REMOVAL
(1) Lower the steering column. Refer to Column
Assembly Replacement in this group.
Fig. 1 Steering Column Non-Serviceable
Components
Fig. 2 Steering Column Flash Removal And
Non-Serviceable Components
Fig. 3 Observe Cautions
Fig. 4 Observe Cautions
JSTEERING 19 - 55

(2) Remove two screws retaining the interlock
mechanism to the column (Fig. 3). Unsnap the mech-
anism from column.
(3) Remove the center console and related trim.
Refer to Group 23, Body.
(4) Disconnect the cable eyelet from the bellcrank
(Fig. 4).
(5) Disconnect and remove the cable from the shift
bracket.
(6) Remove the accelerator pedal (the cable routes
under the pedal), refer to Group 14, Fuel Systems.
Release the cable from the accelerator pedal clip.
Move the carpet as necessary to remove the cable.INSTALLATION/ADJUSTMENT
(1) Snap the cable base assembly into the large
square opening in the steering column (Fig. 4).
(2) Secure the plastic base with two (2) self tap-
ping screws (Fig. 3).
Fig. 1 Ignition Interlock Cable Routing
Fig. 2 Ignition Key Cylinder Actuation
Fig. 3 Interlock Mechanism on Column
19 - 56 STEERINGJ