1995 JEEP CHEROKEE engine

(3) Remove ignition coil mounting bolts (nuts are
used on back side of bracket). Remove coil.
INSTALLATION
(1) Install ignition coil to bracket on cylinder block
with mounting bolts and nuts.
(2) Connect engine harness connector to coil.
(3) Connect ignition coil cable to ignition coil.
INTAKE MANIFOLD AIR TEMPERATURE SENSOR
For an operational description, diagnosis or remov-
al/ installation procedures, refer to Group 14, Fuel
Systems.
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
For an operational description, diagnosis and re-
moval/installation procedures, refer to Group 14,
Fuel System.
OXYGEN (O2S) SENSOR
For an operational description, diagnosis or remov-
al/ installation procedures, refer to Group 14, Fuel
Systems.
POWERTRAIN CONTROL MODULE (PCM)
The PCM was formerly referred to as the SBEC or
engine controller.
XJ MODELS
On XJ models, the PCM is located in the engine
compartment next to the air cleaner (Fig. 17).
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Loosen 60-way connector mounting screw until
connector can be disengaged from PCM.
(3) Pull 60-way connector straight back from PCM.
(4) Remove PCM mounting bolts.
(5) Remove PCM from vehicle.INSTALLATION
(1) Check the pins in the PCM 60-way electrical
connector for damage. Repair as necessary.
(2) Install PCM. Tighten mounting bolts to 1 Nzm
(9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting screw to 4 Nzm (35 in. lbs.)
torque.
(4) Connect battery cable to battery.
YJ MODELS
On YJ models, the PCM is located in the engine
compartment behind the windshield washer fluid res-
ervoir (Fig. 18).
REMOVAL
(1) Disconnect negative battery cable at battery.
(2) Remove windshield washer fluid reservoir.
(3) Loosen 60-way connector mounting screw until
connector can be disengaged from PCM.
(4) Pull 60-way connector straight back from PCM.
(5) Remove PCM mounting bolts.
(6) Remove PCM from vehicle.
INSTALLATION
(1) Check the pins in the PCM 60-way electrical
connector for damage. Repair as necessary.
(2) Install PCM. Tighten mounting bolts to 1 Nzm
(9 in. lbs.) torque.
(3) Engage 60-way connector into PCM. Tighten
connector mounting screw to 4 Nzm (35 in. lbs.)
torque.
(4) Connect battery cable to battery.
(5) Install washer fluid reservoir.
SPARK PLUGS
PLUG REMOVAL
(1) Always remove spark plug or ignition coil ca-
bles by grasping at the cable boot (Fig. 19). Turn the
cable boot 1/2 turn and pull straight back in a steady
Fig. 17 PCM LocationÐXJ Models
Fig. 18 PCM LocationÐYJ Models
JIGNITION SYSTEMS 8D - 23

motion. Never pull directly on the cable. Internal
damage to cable will result.
(2) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert.
(4) Inspect the spark plug condition. Refer to
Spark Plugs in the Diagnostics/Service Procedures
section of this group.
PLUG CLEANING
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After clean-
ing, file the center electrode flat with a small point
file or jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will re-
main on the spark plug insulator and will cause
plug misfire.
PLUG GAP ADJUSTMENT
Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 20).Never attempt to adjust
the gap by bending the center electrode.
SPARK PLUG GAP
²2.5L 4-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
²4.0L 6-Cylinder Engine Spark Plug Gap: .89 mm
(.035 in).
PLUG INSTALLATION
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion. This may result
in a change in the spark plug gap, or a cracked por-
celain insulator.
When replacing the spark plug and ignition coil ca-
bles, route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise. It could cause cross ignition of the spark plugs,
or short circuit the cables to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Tighten the spark plugs to 35-41 Nzm (26-30 ft.
lbs.) torque.
(3) Install spark plug cables over spark plugs.
SPARK PLUG SECONDARY CABLES
CAUTION: When disconnecting a high voltage cable
from a spark plug or from the distributor cap, twist
the rubber boot slightly (1/2 turn) to break it loose
(Fig. 19). Grasp the boot (not the cable) and pull it
off with a steady, even force.
Install cables into the proper engine cylinder firing
order (Figs. 21 or 22).
When replacing the spark plug and coil cables,
route the cables correctly and secure in the proper
retainers. Failure to route the cables properly can
cause the radio to reproduce ignition noise. It could
also cause cross ignition of the plugs, or short circuit
the cables to ground.
Fig. 19 Cable Removal
Fig. 20 Setting Spark Plug GapÐTypical
8D - 24 IGNITION SYSTEMSJ

When installing new cables, make sure a positive
connection is made. A snap should be felt when a
good connection is made between the plug cable and
the distributor cap tower.THROTTLE POSITION SENSOR (TPS)
For an operational description, diagnosis and re-
moval/installation procedures, refer to Group 14,
Fuel System.
Fig. 22 Engine Firing OrderÐ4.0L 6-Cylinder EngineFig. 21 Engine Firing OrderÐ2.5L 4-Cylinder Engine
JIGNITION SYSTEMS 8D - 25

SPECIFICATIONS
GENERAL INFORMATION
The following specifications are published from the
latest information available at the time of publica-
tion.If anything differs between the specifica-
tions found on the Vehicle Emission Control
Information (VECI) label and the following
specifications, use specifications on VECI label.
The VECI label is located in the engine compart-
ment.
SPARK PLUGS
ENGINE FIRING ORDERÐ2.5L 4-CYLINDER
ENGINE
ENGINE FIRING ORDERÐ4.0L 6-CYLINDER
ENGINE
TORQUE
8D - 32 IGNITION SYSTEMSJ

INSTRUMENT PANEL AND GAUGES
GROUP INDEX
INSTRUMENT PANEL AND GAUGESÐXJ...... 1INSTRUMENT PANEL AND GAUGESÐYJ..... 24
INSTRUMENT PANEL AND GAUGESÐXJ
CONTENTS
page page
DIAGNOSIS............................. 5
GENERAL INFORMATION.................. 1SERVICE PROCEDURES.................. 17
SPECIFICATIONS........................ 23
GENERAL INFORMATION
Following are general descriptions of major instru-
ment panel components. Refer to Group 8W - Wiring
Diagrams for complete circuit descriptions and dia-
grams.
INSTRUMENT PANEL
Modular instrument panel construction allows all
gauges and controls to be serviced from the front of
the panel. In addition, most instrument panel wiring
or heater and air conditioning components can be ac-
cessed without complete instrument panel removal. If
necessary, the instrument panel can be rolled-down
and removed from the vehicle as an assembly.
Removal of the instrument cluster bezel allows ac-
cess to the cluster assembly, most switches, the cli-
mate controls, and the radio. Removal of the cluster
assembly allows access to the individual gauges, illu-
mination and indicator lamp bulbs, printed circuits,
and most wiring.
Removal of the lower instrument panel allows ac-
cess to heater and air conditioning components, the
fuseblock module, the relay center, and other wiring
and electrical components. Those models equipped
with a driver's-side airbag restraint have a knee
blocker and reinforcement behind the driver's-side
lower instrument panel.
The instrument panel layout is mirror image for
left-hand and right-hand drive vehicles. In most
cases, the diagnosis and service procedures found in
this group are applicable to either vehicle. Although,most illustrations represent only the typical left-hand
drive version. Exceptions are clearly identified as
Right-Hand Drive (RHD).
INSTRUMENT CLUSTERS
Two basic instrument cluster options are offered on
XJ (Cherokee) models. One is referred to as a low-
line cluster, and the other is referred to as a high-
line cluster. Each cluster is divided into two areas:
the gauge area, and the tell-tale area. Each area is
served by a separate printed circuit and wiring con-
nector. Some variations of each cluster exist due to
optional equipment and regulatory requirements.
The low-line cluster includes the following gauges:
²fuel gauge
²speedometer/odometer.
The low-line cluster includes provisions for the fol-
lowing indicator lamps:
²anti-lock brake system lamp
²brake warning lamp
²coolant temperature warning lamp
²four-wheel drive indicator lamps
²generator warning lamp
²headlamp high beam indicator lamp
²low oil pressure warning lamp
²low washer fluid warning lamp
²malfunction indicator (Check Engine) lamp
²seat belt reminder lamp
²turn signal indicator lamps
²upshift indicator lamp.
JINSTRUMENT PANEL AND GAUGES 8E - 1

The high-line cluster includes the following gauges:
²coolant temperature gauge
²fuel gauge
²oil pressure gauge
²speedometer/odometer
²tachometer
²trip odometer
²voltmeter.
The high-line cluster includes provisions for the fol-
lowing indicator lamps:
²anti-lock brake system lamp
²brake warning lamp
²four-wheel drive indicator lamps
²headlamp high beam indicator lamp
²low fuel warning lamp
²low washer fluid warning lamp
²malfunction indicator (Check Engine) lamp
²seat belt reminder lamp
²turn signal indicator lamps
²upshift indicator lamp.
GAUGES
With the ignition switch in the ON or START posi-
tion, voltage is supplied to all gauges through the in-
strument cluster gauge area printed circuit. With the
ignition switch in the OFF position, voltage is not
supplied to the gauges. A gauge pointer may remain
within the gauge scale after the ignition switch is
OFF. However, the gauges do not accurately indicate
any vehicle condition unless the ignition switch is
ON.
All gauges except the odometer are air core mag-
netic units. Two fixed electromagnetic coils are lo-
cated within the gauge. These coils are wrapped at
right angles to each other around a movable perma-
nent magnet. The movable magnet is suspended
within the coils on one end of a shaft. The gauge nee-
dle is attached to the other end of the shaft.
One of the coils has a fixed current flowing through
it to maintain a constant magnetic field strength.
Current flow through the second coil changes, which
causes changes in its magnetic field strength. The
current flowing through the second coil can be
changed by:
²a variable resistor-type sending unit (fuel level,
coolant temperature, or oil pressure)
²changes in electrical system voltage (voltmeter)
²electronic control circuitry (speedometer/odometer,
tachometer).
The gauge needle moves as the movable permanent
magnet aligns itself to the changing magnetic fields
created around it by the electromagnets.
COOLANT TEMPERATURE GAUGE
The coolant temperature gauge gives an indication
of engine coolant temperature. The coolant tempera-
ture sending unit is a thermistor that changes elec-
trical resistance with changes in engine coolanttemperature. High sending unit resistance causes
low coolant temperature readings. Low resistance
causes high coolant temperature readings.
The gauge will read at the high end of the scale
when the ignition switch is turned to the START po-
sition. This is caused by the bulb test circuit wiring
provision. The same wiring is used for the high-line
cluster with a coolant temperature gauge and the
low-line cluster with a coolant temperature warning
lamp. Sending unit resistance values are shown in a
chart in Specifications.
FUEL GAUGE
The fuel gauge gives an indication of the level of
fuel in the fuel tank. The fuel gauge sending unit has
a float attached to a swing-arm in the fuel tank. The
float moves up or down within the fuel tank as fuel
level changes. As the float moves, an electrical con-
tact on the swing-arm wipes across a resistor coil,
which changes sending unit resistance. High sending
unit resistance causes low fuel level readings. Low
resistance causes high fuel level readings. Sending
unit resistance values are shown in a chart in Spec-
ifications.
OIL PRESSURE GAUGE
The oil pressure gauge gives an indication of en-
gine oil pressure. The combination oil pressure send-
ing unit contains a flexible diaphragm. The
diaphragm moves in response to changes in engine
oil pressure. As the diaphragm moves, sending unit
resistance increases or decreases. High resistance on
the gauge side of the sending unit causes high oil
pressure readings. Low resistance causes low oil
pressure readings. Sending unit resistance values are
shown in a chart in Specifications.
SPEEDOMETER/ODOMETER
The speedometer/odometer gives an indication of
vehicle speed and travel distance. The speedometer
receives a vehicle speed pulse signal from the Vehicle
Speed Sensor (VSS). An electronic integrated circuit
contained within the speedometer reads and analyzes
the pulse signal. It then adjusts the ground path re-
sistance of one electromagnet in the gauge to control
needle movement. It also sends signals to an electric
stepper motor to control movement of the odometer
number rolls. Frequency values for the pulse signal
are shown in a chart in Specifications.
The VSS is mounted to an adapter near the trans-
mission (two-wheel drive) or transfer case (four-wheel
drive) output shaft. The sensor is driven through the
adapter by a speedometer pinion gear. The adapter
and pinion vary with transmission, transfer case,
axle ratio and tire size. Refer to Group 21 - Trans-
mission and Transfer Case for more information.
8E - 2 INSTRUMENT PANEL AND GAUGESÐXJJ

TACHOMETER
The tachometer gives an indication of engine speed
in Revolutions-Per-Minute (RPM). With the engine
running, the tachometer receives an engine speed
pulse signal from the Powertrain Control Module
(PCM). An electronic integrated circuit contained
within the tachometer reads and analyzes the pulse
signal. It then adjusts the ground path resistance of
one electromagnet in the gauge to control needle
movement. Frequency values for the pulse signal are
shown in a chart in Specifications.
TRIP ODOMETER
The trip odometer is driven by the same electronic
integrated circuit as the speedometer/odometer. How-
ever, by depressing the trip odometer reset knob on
the face of the speedometer, the trip odometer can be
reset to zero. The trip odometer is serviced only as a
part of the speedometer/odometer gauge assembly.
VOLTMETER
The voltmeter is connected in parallel with the bat-
tery. With the ignition switch ON, the voltmeter in-
dicates battery or generator output voltage,
whichever is greater.
INDICATOR LAMPS
Indicator lamps are located in two areas within the
cluster. Each of these areas is served by a separate
printed circuit and cluster connector. Those lamps in
the gauge area of the cluster share the gauge area
printed circuit and cluster connector A. Those lamps
in the tell-tale area of the cluster use the tell-tale
printed circuit and cluster (tell-tale) connector B.
Up to ten indicator lamps can be found in the tell-
tale area of the cluster. These lamps are arranged in
five stacked rows with two lamps in each row, located
to the driver's side of the main cluster.
ANTI-LOCK BRAKE SYSTEM LAMP
The Anti-Lock Brake System (ABS) lamp is
switched to ground by the ABS module. The module
lights the lamp when the ignition switch is turned to
the START position as a bulb test. The lamp will
stay on for 3 to 5 seconds after vehicle start-up to in-
dicate a system self-test is in process. If the lamp re-
mains on after start-up, or comes on and stays on
while driving, it may indicate that the ABS module
has detected a system malfunction or that the system
has become inoperative. Refer to Group 5 - Brakes
for more information.
BRAKE WARNING LAMP
The brake warning lamp warns the driver that the
parking brake is applied or that the pressures in the
two halves of the split brake hydraulic system are
unequal. With the ignition switch turned ON, batteryvoltage is supplied to one side of the indicator bulb. A
ground path for the bulb is provided by 3 switches.
The bulb will light when:
²the brake warning switch is closed (indicating un-
equal brake system hydraulic pressures possibly due
to brake fluid leakage)
²the ignition switch is in the START position (bulb
test)
²the parking brake switch is closed (parking brake
is applied).
Refer to Group 5 - Brakes for more information.
COOLANT TEMPERATURE WARNING LAMP
The coolant temperature warning lamp lights
whenever engine coolant temperature is too high.
Battery voltage is supplied to one side of the indica-
tor bulb when the ignition switch is turned ON. The
normally open coolant temperature switch is con-
nected to the other side of the bulb. When coolant
temperature is too high, the switch closes. This pro-
vides a ground path for the indicator bulb, which
causes it to light. The lamp is also grounded and
should light with the ignition switch in the START
position as a bulb test.
FOUR-WHEEL DRIVE INDICATOR LAMPS
PART TIME
On vehicles with Command-Trac 4WD, the Part
Time lamp lights when the transfer case is engaged
in the 4H or 4L position. On vehicles with Selec-Trac
4WD, the Part Time lamp lights when the transfer
case is engaged in the4X4PARTTIME or 4 LO po-
sition. Voltage is supplied to one side of the indicator
bulb. A switch in the transfer case is connected to the
other side of the indicator bulb. When the switch is
closed, a path to ground is provided and the indicator
bulb lights.
FULL TIME
The Full Time lamp is only operational on vehicles
equipped with Selec-Trac 4WD. The Full Time lamp
lights when the transfer case is engaged in the4X4
Full Time position. Voltage is supplied to one side of
the indicator bulb. A switch in the transfer case is
connected to the other side of the indicator bulb.
When the switch is closed, a path to ground is pro-
vided and the indicator bulb lights.
GENERATOR WARNING LAMP
The generator warning lamp lights with the igni-
tion switch turned to ON, but should go out when-
ever the engine is running. If the lamp comes on and
stays on while the engine is running, it indicates
that a charging system malfunction exists. One side
of the bulb is connected to ignition-switched battery
feed. The other side of the bulb is switched to ground
by the Powertrain Control Module (PCM).
JINSTRUMENT PANEL AND GAUGESÐXJ 8E - 3

HEADLAMP HIGH BEAM INDICATOR LAMP
The high beam indicator lamp is controlled by the
headlamp dimmer (multi-function) switch. One side
of the indicator bulb is grounded at all times. The
other side of the bulb receives battery feed through
the contacts of the dimmer switch when the multi-
function switch stalk is actuated to turn the head-
lamp high beams on. Refer to Group 8L - Lamps for
more information.
LOW FUEL WARNING LAMP
A Light-Emitting Diode (LED) on the face of the
fuel gauge will light when the fuel level falls below
approximately 4 gallons. A low fuel warning module
attached to the rear of the fuel gauge controls when
the LED will light. When the module senses 66.5
ohms or more resistance from the fuel level sending
unit for 10 continuous seconds, the LED will light.
When the module senses 63.5 ohms or less resistance
from the fuel level sending unit for 20 continuous
seconds, the LED is turned off.
LOW OIL PRESSURE WARNING LAMP
The low oil pressure warning lamp lights with the
ignition switch in the ON position and the engine not
running. The lamp should be off when the engine is
running. Battery voltage is supplied to one side of
the indicator bulb when the ignition switch is turned
ON. The warning lamp side of the combination oil
pressure sending unit is connected to the other side
of the bulb. When normal engine oil pressure is ap-
plied to the sending unit, resistance on the warning
lamp side is high and the lamp goes off. When engine
oil pressure is too low, resistance on the warning
lamp side of the sending unit is low, which causes
the bulb to light.
LOW WASHER FLUID WARNING LAMP
The low washer fluid warning lamp indicates when
the fluid level in the washer reservoir is too low. The
washer fluid level sensor uses a float in the reservoir
to monitor fluid level. The action of the float opens or
closes the switch within the sensor that provides ig-
nition-switched battery voltage to the lamp bulb. Re-
fer to Group 8K - Wiper and Washer Systems for
more information.
MALFUNCTION INDICATOR LAMP
The CHECK ENGINE or Malfunction Indicator
Lamp (MIL) lights each time the ignition switch is
turned ON, and stays on for 3 seconds as a bulb test.
If the Powertrain Control Module (PCM) receives an
incorrect signal or no signal from certain fuel oremission system related circuits or components, the
lamp is turned on. This will indicate that the PCM
has recorded a Diagnostic Trouble Code (DTC) in
electronic memory for a circuit or component mal-
function. Refer to Group 14 - Fuel System for more
information.
SEAT BELT REMINDER LAMP
The seat belt reminder lamp lights for 4 to 8 sec-
onds after the ignition switch is turned to the ON po-
sition. A timer in the chime/buzzer module controls
ignition-switched battery feed to the lamp. Refer to
Group 8U - Chime/Buzzer Warning Systems for more
information.
TURN SIGNAL INDICATOR LAMPS
The left and right turn signal indicator lamps are
controlled by the turn signal and hazard warning
(multi-function) switches. One side of the bulb for
each lamp is grounded at all times. The other side of
the bulb receives battery feed through the contacts of
the multi-function switch when the turn signal lever
(multi-function switch stalk) or hazard warning but-
ton are actuated. Refer to Group 8J - Turn Signal
and Hazard Warning Systems for more information.
UPSHIFT INDICATOR LAMP
Vehicles equipped with manual transmissions have
an optional upshift indicator lamp. Ground feed for
the lamp is switched by the Powertrain Control Mod-
ule (PCM). The lamp lights to indicate when the
driver should shift to the next highest gear for best
fuel economy. The PCM will turn the lamp off after 3
to 5 seconds if the upshift is not performed. The lamp
will remain off until the vehicle stops accelerating
and is brought back to the range of lamp operation,
or until the transmission is shifted into another gear.
The indicator lamp is normally on when the igni-
tion switch is turned ON and is turned off when the
engine is started. The lamp will be turned on during
vehicle operation according to engine speed and load.
CLUSTER ILLUMINATION LAMPS
All cluster illumination lamps receive battery feed
from the instrument lamps fuse in the fuseblock
module through the panel dimmer rheostat of the
headlamp switch. When the park or headlamps are
on, the cluster illumination lamps light. Illumination
brightness can be adjusted by rotating the headlamp
switch knob (clockwise to dim, counterclockwise to
brighten).
8E - 4 INSTRUMENT PANEL AND GAUGESÐXJJ