1994 JEEP CHEROKEE automatic transmission

contact at battery cable to solenoid connection. If
reading is still above 0.2 volt, replace positive bat-
tery cable.
(5) Connect voltmeter to measure between the bat-
tery negative post and the engine block (Fig. 4).
(6) Rotate and hold ignition switch in the START po-
sition. If voltage reads above 0.2 volt, correct poor con-tact at ground cable attaching point. Voltage reading
still above 0.2 volt, replace ground cable.
(7) Connect positive voltmeter lead to starter mo-
tor housing. Connect negative lead to battery nega-
tive terminal (Fig. 5).
(8) Rotate and hold ignition switch in the START
position. If voltage reads above 0.2 volt, correct poor
starter to engine ground.
If resistance tests detect no feed circuit failures, re-
move the starter motor and go to Solenoid Testing.
STARTER CONTROL CIRCUIT TESTS
The starter control circuit consists of a starter so-
lenoid, starter relay, ignition switch, park/neutral po-
sition switch (automatic transmission), and all their
wiring and connections.
Testing procedures for these components are as fol-
lows and should be followed in order as described.
CAUTION: Before performing any test, disconnect dis-
tributor connector to prevent engine from starting.
SOLENOID TESTING
Refer to Group 8B - Battery/Starter/Generator Ser-
vice for starter removal procedures.
(1) Disconnect field coil wire from field coil terminal.
(2) Check for continuity between solenoid terminal
and field coil terminal with a continuity tester.
There should be continuity (Fig. 6).
Fig. 2 Test Battery Connection Resistance
Fig. 3 Test Positive Battery Cable Resistance
(Typical)
Fig. 4 Test Ground Circuit Resistance
Fig. 5 Test Starter Motor Ground (Typical)
Fig. 6 Continuity Test Between Solenoid Terminal
and Field Coil Terminal
JBATTERY/STARTING/CHARGING SYSTEMS DIAGNOSTICS 8A - 11

ENGINE STARTER MOTOR SERVICE PROCEDURES
INDEX
page page
2.5L Starter General Information.............. 4
2.5L Starter Motor Removal/Installation......... 5
4.0L Starter General Information.............. 6
4.0L Starter Motor Removal/Installation......... 6General Information........................ 4
Park/Neutral Position Switch................. 6
Starter Relay Replacement.................. 4
GENERAL INFORMATION
This section will cover the starting system compo-
nent service procedures only. For diagnostic proce-
dures, refer to Group 8A - Battery/Starting/Charging
Systems Diagnostics.
Starting system components: battery, starter mo-
tor, starter relay, starter solenoid, ignition switch,
connecting wires and battery cables. A park/neutral
position switch is used with automatic transmissions.
STARTER RELAY REPLACEMENT
The starter relay is located in the Power Distribu-
tion Center (Figs. 1 and 2). Refer to underside of
Power Distribution Center cover for relay location.
(1) Disconnect negative cable from battery.
(2) Replace relay.
(3) Connect negative cable to battery.
(4) Test relay operation.
2.5L STARTER GENERAL INFORMATION
The 2.5L engine starter motor incorporates several
features to create an efficient, lightweight unit.
A planetary gear system (intermediate transmis-
sion) between the electric motor and pinion shaftmakes it possible to reduce the dimensions of the
starter. This also makes it possible to obtain a higher
rotational speed to produce the same torque at the
pinion.
The permanent magnet field consists of six two-
component high strength magnets. The magnets are
aligned according to their polarity and are perma-
nently fixed in the starter frame.
The brush holder plate consists of a plastic base-
plate with four tubular brush holders.
This unit is highly sensitive to hammering, shocks
and external pressure.
CAUTION: The starter motor MUST NOT BE
CLAMPED in a vise by the starter frame. Doing so
may damage the magnets. It may be clamped by the
mounting flange ONLY.
CAUTION: Do not connect starter motor incorrectly
when tests are being performed. The magnets may
be damaged and rendered unserviceable.
²Ensure cleanliness when performing repairs.
Fig. 1 Power Distribution CenterÐXJ
Fig. 2 Power Distribution CenterÐYJ
8B - 4 BATTERY/STARTER/GENERATOR SERVICEJ

²Metal chips are attracted by the magnets and may
not be completely removed from the starter frame.
Chips in the ring gear can lead to failure of the
starter.
2.5L STARTER MOTOR REMOVAL/INSTALLATION
XJÐ2.5L ENGINE
(1) Disconnect negative cable from battery.
(2) Remove exhaust clamp from bracket (Fig. 3).
(3) Remove nut and bolt from forward end of brace
rod (automatic transmission only).
(4) Remove nut from lower end of brace rod (auto-
matic transmission only).
(5) Remove brace rod and bracket (automatic
transmission only).
(6) Remove nut, bolt and bracket from bell housing
(manual transmission only).
(7) Disconnect battery cable and solenoid feed wire
from solenoid (Fig. 4).
(8) Remove starter motor mounting bolts, starter
motor and shims.
Two shim thicknesses are available. One is
0.381 mm (0.015 in.) and the other is 1.143 mm
(0.045 in.). Refer to Group 8A for proper shim se-
lection.
(9) To install starter motor, reverse the removal
procedures and torque mounting hardware as shown.
(10) Connect negative cable to battery.
YJÐ2.5L ENGINE
(1) Disconnect negative cable from battery.
(2) Disconnect battery cable from starter motor
B+ terminal (Fig. 5).(3) Disconnect solenoid feed wire.
(4) Remove starter motor mounting bolts.
(5) Remove starter motor and shims.
Two shim thicknesses are available. One is
0.381 mm (0.015 in.) and the other is 1.143 mm
(0.045 in.). Refer to Group 8A for proper shim se-
lection.
(6) To install starter motor, reverse removal proce-
dures and torque mounting hardware as shown.
(7) Connect negative cable to battery.
Fig. 3 Exhaust Clamp and Brace RemovalÐ2.5L XJ
Fig. 4 Starter Motor Removal/InstallationÐ2.5L XJ
Fig. 5 Starter Motor Removal/InstallationÐ2.5L YJ
JBATTERY/STARTER/GENERATOR SERVICE 8B - 5

Engine speed and crankshaft position are provided
through the crankshaft position sensor. The sensor
generates pulses that are the input sent to the Pow-
ertrain Control Module (PCM). The PCM interprets
the sensor input to determine the crankshaft posi-
tion. The PCM then uses this position, along with
other inputs, to determine injector sequence and ig-
nition timing.
The sensor is a hall effect device combined with an
internal magnet. It is also sensitive to steel within a
certain distance from it.
SENSOR OPERATION
The flywheel/drive plate has groups of four notches
at its outer edge. On 4.0L 6 cylinder engines there
are three sets of notches (Figs. 9 or 10). On 2.5L 4
cylinder engines there are two sets of notches (Fig.
8).
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the inputto the PCM. For each engine revolution there are
two groups of four pulses generated on 2.5L 4 cylin-
der engines. There are 3 groups of four pulses gener-
ated on 4.0L 6 cylinder engines.
The trailing edge of the fourth notch, which causes
the pulse, is four degrees before top dead center
(TDC) of the corresponding piston.
The engine will not operate if the PCM does not re-
ceive a crankshaft position sensor input.
For component testing, refer to the Diagnostics/Ser-
vice Procedures section of this group.
For removal and installation of this sensor, refer to
the Component Removal/Installation section of this
group.
DISTRIBUTORS
All engines are equipped with a camshaft driven
mechanical distributor containing a shaft driven dis-
tributor rotor. All distributors are equipped with an
internal camshaft position (fuel sync) sensor. This
sensor provides fuel injection synchronization and
cylinder identification.
The distributors on the 2.5L and 4.0L engines do
not have built in centrifugal or vacuum assisted ad-
vance. Base ignition timing and all timing advance
is controlled by the Powertrain Control Module
(PCM). Because ignition timing is controlled by the
PCM,base ignition timing is not adjustable on
any of these engines.
The distributor is locked in place by a notch on the
distributor housing. The distributor holddown clamp
bolt passes through this notch when installed. Be-
cause the distributor position is locked when in-
Fig. 5 Crankshaft Position SensorÐ2.5L
EngineÐTypical
Fig. 6 Crankshaft Position SensorÐ4.0L EngineÐAll
Except YJ models With Automatic Transmission
Fig. 7 Crankshaft Position SensorÐ4.0L EngineÐYJ
models With Automatic Transmission
JIGNITION SYSTEMS 8D - 3

stalled, its rotational position can not be changed.
Do not attempt to modify the distributor housing
to get distributor rotation. Distributor position
will have no effect on ignition timing.
All distributors contain an internal oil seal that
prevents oil from entering the distributor housing.
The seal is not serviceable.
For component testing, refer to the Diagnostics/Ser-
vice Procedures section of this group.For removal and installation of this component, re-
fer to the Component Removal/Installation section of
this group.
IGNITION COIL
Battery voltage is supplied to the ignition coil pos-
itive terminal from the ASD relay.
The Powertrain Control Module (PCM) opens and
closes the ignition coil ground circuit for ignition coil
operation.
Base ignition timing is not adjustable.By con-
trolling the coil ground circuit, the PCM is able to
set the base timing and adjust the ignition timing
advance. This is done to meet changing engine oper-
ating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
The ignition coil is mounted to a bracket on the
side of the engine (Fig. 11).
For component testing, refer to the Diagnostics/Ser-
vice Procedures section of this group.
For removal and installation of this component, re-
fer to the Component Removal/Installation section of
this group.
ENGINE COOLANT TEMPERATURE SENSOR
The engine coolant temperature sensor provides an
input voltage to the Powertrain Control Module
(PCM) relating coolant temperature. The PCM uses
this input, along with inputs from other sensors, to
determine injector pulse width and ignition timing.
Fig. 8 Sensor OperationÐ2.5L Engine
Fig. 9 Sensor OperationÐ4.0L EngineÐAll Except
YJ Models With Automatic Transmission
Fig. 10 Sensor OperationÐ4.0L EngineÐYJ Models
With Automatic Transmission
8D - 4 IGNITION SYSTEMSJ

INSTALLATION
(1) Position the camshaft position sensor in the
distributor housing. Place the wire harness grommet
into the opening in the distributor housing.
(2) Install retaining arm and retaining screw.
(3) Install distributor shaft into distributor hous-
ing. Make sure the upper thrust washer is installed
on the shaft.
(4) Position thrust washer and drive gear on dis-
tributor shaft.
(5) Note the previousCAUTIONand install dis-
tributor drive gear roll pin.
(6) Install rotor.
(7) Install distributor.
CRANKSHAFT POSITION SENSOR
The crankshaft position sensor is mounted in thetransmission bellhousing at the left/rear side of the
engine block (Figs. 5, 6 or 7).
On all 2.5L and 4.0L engines (except YJ models
with an automatic transmission and 4.0L engine) the
sensor is attached with two bolts. The 2.5L engine,
when equipped with an automatic transmission, will
have the sensor mounted with two nuts.
On YJ models with a 4.0L engine and automatic
transmission, the sensor uses a single slotted hole to
adjust its depth. A paper/cardboard type spacer with
self-adhesive (Fig. 7) is attached to the bottom of the
sensor to set this depth. After the engine has been
started (and after sensor installation), this temporary
spacer will be sheared off. New factory replacement
sensors are equipped with this spacer. If the original
sensor is to be reinstalled, such as with transmission
and/or flywheel removal, a new spacerMUSTbe in-
stalled.
Fig. 3 Distributor GearÐRemoval/Installation
Fig. 4 Camshaft Position Sensor
Fig. 5 Crankshaft Position SensorÐ2.5L
EngineÐTypical
Fig. 6 Crankshaft Position SensorÐ4.0L EngineÐAll
Except YJ models With Automatic Transmission
JIGNITION SYSTEMS 8D - 21

REMOVALÐALL ENGINES
(1) Near the rear of the intake manifold, discon-
nect the pigtail harness (on the sensor) from the
main electrical harness.
(2) Remove the nut holding sensor wire clip to fuel
rail mounting stud.
(3) Depending upon application, remove either the
sensor mounting bolt(s) or nuts.
(4) Remove the sensor.
(5) Remove clip from sensor wire harness.
INSTALLATIONÐALL EXCEPT YJ MODELS
WITH 4.0L ENGINE AND AUTOMATIC
TRANSMISSION
(1) Install the sensor flush against the opening in
the transmission housing.
(2) Install and tighten the two sensor mounting
bolts (or nuts) to 19 Nzm (14 ft. lbs.) torque.
CAUTION: On some models, two bolts used to se-
cure the sensor to the transmission. These bolts
are specially machined to correctly space the unit
to the flywheel. Do not attempt to install any other
bolts.
(3) Connect the electrical connector to the sensor.
(4) Install clip on sensor wire harness.
(5) Install clip over fuel rail mounting stud. Install
clip mounting nut.
INSTALLATIONÐYJ MODELS WITH 4.0L
ENGINE AND AUTOMATIC TRANSMISSION
(1) Be sure the paper/cardboard spacer (Fig. 7) has
been installed to the bottom of the new sensor.If original sensor is being reinstalled (such as with
transmission or flywheel removal), clean bottom of
the sensor before installation. Obtain a new spacer
and remove the paper backing. Install the self-adhe-
sive side to bottom of sensor. This spacerMUSTbe
installed. If spacer is not installed, sensor will be
damaged when engine is started.
(2) Position sensor to transmission bellhousing and
install mounting bolt finger tight.
(3) Gently seat (push down) the sensor until the
paper spacer contacts the outer edge of the flywheel.
(4) Tighten sensor mounting bolt (Fig. 7) to 17-
to-21 Nzm (13-to-16 ft. lbs.) torque.
(5) Connect the electrical connector to sensor.
(6) Install the clip to sensor wire harness.
(7) Install clip over fuel rail mounting stud. Install
clip mounting nut.
ENGINE COOLANT TEMPERATURE SENSOR
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR. RE-
FER TO GROUP 7, COOLING.
REMOVAL
The sensor is installed in the thermostat housing
(Fig. 8).
(1) Drain cooling system until the coolant level is
below the cylinder head. For cooling system draining,
refer to Group 7, Cooling.
(2) Disconnect the coolant temperature sensor wire
connector.
(3) Remove the sensor from the thermostat hous-
ing (Fig. 8).
Fig. 7 Crankshaft Position SensorÐ4.0L EngineÐYJ
models With Automatic Transmission
Fig. 8 Coolant Temperature SensorÐTypical
8D - 22 IGNITION SYSTEMSJ

Wiring Diagram Name Sheet Number
Left Back-Up Lamp..........................51
Left Courtesy Lamp.........................35
Left Fog Lamp..........................25, 27
Left Headlamp..........................25, 27
Left Park and Turn Signal Lamp..............25, 27
Left Side Marker Lamp....................25, 27
Left Tail, Stop and Turn Signal Lamp..............51
Right Back-Up Lamp.........................52
Right Courtesy Lamp........................35
Right Fog Lamp.........................26, 28
Right Headlamp.........................26, 28
Right Park and Turn Signal Lamp.............26, 28
Right Side Marker Lamp...................26, 28
Right Tail, Stop and Turn Signal Lamp.............52
Underhood Lamp............................8
Left Back-Up Lamps..........................51
Left Courtesy Lamp...........................35
Left Fog Lamp...........................25, 27
Left Front Door Jamb Switch.....................35
Left Front Speaker............................46
Left Halo Speaker............................46
Left Headlamp............................25, 27
Left Park and Turn Signal Lamp................25, 27
Left Side Marker Lamp......................25, 27
Left Tail, Stop and Turn Signal Lamp...............51
MAP Sensor.............................15, 21
Mercury Switch..............................8
Modules
ABS Control Module....................57, 58, 59
Buzzer Module.............................36
Daytime Running Lamp Module.................28
Intermittent Wiper Module.....................40
Motors
Blower Motor.............................47
Engine Starter Motor.........................7
Idle Air Control Motor.....................14, 20
Rear Wiper Motor..........................37
Wiper Motor...........................38, 39
Oil Pressure and Temp System...................23
Panel Lamp Dimmer Switch......................1
Panel Lamps.............................31, 32
Accessory Illumination........................32
Heater Control Panel Illumination.................32
Panel Lamp Dimmer Switch....................31
Transmission Range Illumination.................32
Park Brake Switch.............................9
Park/Neutral Position Switch......................7
Part Throttle EMCC 3-Speed Automatic Transmission.....56
Part Throttle EMCC Relay.......................56
Part Throttle EMCC Solenoid.....................56
Power Distribution Center.................1,4,6,57
Power Distribution Center Identification Cover..........67
Power Distribution Center Relays..................68
Power Steering Switch.........................14
Powertrain Control Module............11-22, 48, 49, 56
Powertrain Control Module Connector (2.5L Engine)......63
Powertrain Control Module Connector (4.0L Engine)......64
Provisions for A/C (2.5L).......................48Wiring Diagram Name Sheet Number
Radio Illumination Relay........................45
Radio System............................45, 46
Electrically Tuned Radio with Clock...............45
Left Front Speaker..........................46
Left Halo Speaker...........................46
Radio Illumination Relay......................45
Right Front Speaker.........................46
Right Halo Speaker..........................46
Rear Lighting............................51, 52
Center High Mounted Stop Lamp................52
Left Back-Up Lamp..........................51
Left Tail, Stop & Turn Signal Lamp & License Lamp....51
Right Back-Up Lamp.........................52
Right Tail, Stop & Turn Signal Lamp..............52
Rear Wiper/Washer System......................37
Rear Wiper Motor..........................37
Rear Wiper Switch..........................37
Washer Pump.............................37
Relays
A/C ....................................49
ABS Motor Pump Relay.......................57
ABS Power Relay...........................57
Automatic Shut Down Relay.................11, 17
EMCC...................................56
Engine Starter Relay..........................7
Fog Lamp Relays...........................30
Fuel Pump Relay........................11, 17
Heated Rear Window Relay....................54
Horn Relay...............................33
Radio Illumination Relay......................45
Right Back-Up Lamp..........................52
Right Courtesy Lamp..........................35
Right Fog Lamp...........................26, 28
Right Front Door Jamb Switch....................35
Right Front Speaker...........................46
Right Halo Speaker...........................46
Right Headlamp...........................26, 28
Right Park and Turn Signal...................26, 28
Right Side Marker Lamp.....................26, 28
Right Tail, Stop and Turn Signal Lamp..............52
Seat Belt/Ignition Key Warning Buzzer...............36
Seat Belt Switch.............................36
Sensors
ABS Accelerator Sensor.......................59
Brake Pedal Travel Sensor.....................57
Camshaft Position Sensor...................12, 18
Crankshaft Position Sensor..................12, 18
Engine Coolant Temperature Sensor............15, 21
Heated Oxygen Sensor.....................11, 17
Intake Air Temperature Sensor................15, 21
MAP Sensor...........................15, 21
Pump Motor Sensor.........................57
Throttle Position (Sensor)...................15, 21
Vehicle Speed Sensor.....................12, 18
Wheel Sensors............................59
Speakers..................................46
Speedometer...............................42
JWIRING DIAGRAMS 8W - 75