coolant level JEEP XJ 1995 Service And Owner's Guide

The engine will not operate if the PCM does not re-
ceive a crankshaft position sensor input.
ENGINE COOLANT TEMPERATURE SENSORÐPCM
INPUT
The engine coolant temperature sensor is installed
in the thermostat housing (Fig. 10) and protrudes
into the water jacket. The sensor provides an input
voltage to the powertrain control module (PCM) re-
lating coolant temperature. The PCM uses this input
along with inputs from other sensors to determine in-
jector pulse width and ignition timing. As coolant
temperature varies, the coolant temperature sensor's
resistance changes. The change in resistance results
in a different input voltage to the PCM.
When the engine is cold, the PCM will operate in
Open Loop cycle. It will demand slightly richer air-
fuel mixtures and higher idle speeds. This is done
until normal operating temperatures are reached.
Refer to Open Loop/Closed Loop Modes of Opera-
tion in this section of the group for more information.
EXTENDED IDLE SWITCHÐPCM INPUT
OPTIONAL POLICE PACKAGE ONLY
The extended idle switch is used to raise the en-
gine idle speed to approximately 1000 rpm. This is
when the shifter is in either the Park or Neutral po-
sition. A rocker-type 2-wire switch (extended idle
switch) is mounted to the instrument panel. This
switch will supply a ground circuit to the powertrain
control module (PCM).The switch is available
only with 4.0L engine when supplied with the
optional police package.
For testing and diagnosis of this switch and its cir-
cuit, refer to the MFI SystemÐGeneral Diagnosis
section of this group.
IGNITION CIRCUIT SENSEÐPCM INPUT
The ignition circuit sense input tells the powertrain
control module (PCM) the ignition switch has ener-
gized the ignition circuit. Refer to the wiring dia-
grams for circuit information.
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐPCM INPUT
The MAP sensor reacts to absolute pressure in the
intake manifold. It provides an input voltage to the
powertrain control module (PCM). As engine load
changes, manifold pressure varies. The change in
manifold pressure causes MAP sensor voltage to
change. The change in MAP sensor voltage results in
a different input voltage to the PCM. The input volt-
age level supplies the PCM with information about
ambient barometric pressure during engine start-up
(cranking) and engine load while the engine is run-
ning. The PCM uses this input along with inputs
from other sensors to adjust air-fuel mixture.
Fig. 8 Sensor LocationÐ4.0L Engine
Fig. 9 Sensor LocationÐ2.5L Engine
Fig. 10 Engine Coolant Temperature SensorÐ
Typical
JFUEL SYSTEM COMPONENT DESCRIPTION/SYSTEM OPERATION 14 - 23

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

oil until you are ready to use it. Install the cap im-
mediately after using. Store the oil only in a clean
moisture-free container.
Keep service tools and the work area clean. Con-
tamination of A/C system through careless work hab-
its must be avoided.
COOLING SYSTEM
To maintain the performance level of the heating/
air conditioning system, the engine cooling system
must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or condenser can
reduce the performance of the A/C and cooling sys-
tem. If a bug screen is used it must be cleaned fre-
quently.
COOLANT PRECAUTIONS
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY.
WARNING: WASH SKIN AND CLOTHING THOR-
OUGHLY AFTER COMING IN CONTACT WITH ETH-
YLENE GLYCOL.
WARNING: KEEP OUT OF REACH OF CHILDREN
AND PETS.
WARNING: DO NOT OPEN A COOLING SYSTEM
WHEN THE ENGINE IS AT RUNNING TEMPERA-
TURE. PERSONAL INJURY CAN RESULT.WARNING: DO NOT STORE IN OPEN OR UN-
MARKED CONTAINERS.
WARNING: HOT ENGINE COOLANT CAN CAUSE
SEVERE BURNS. DO NOT OPEN THE RADIATOR
DRAIN COCK WHEN THE COOLING SYSTEM IS
HOT AND PRESSURIZED. ALLOW THE COOLANT
TO DECREASE TO ROOM TEMPERATURE BEFORE
STARTING REPAIR OPERATIONS.
The engine cooling system is designed to develop
internal pressure of 97 to 124 kPa (14 to 18 psi). Al-
low the vehicle 15 minutes to cool down (or until a
safe temperature and pressure are attained) before
opening the cooling system. Refer to Group 7, Cooling
System.REFRIGERANT HOSES/TUBES PRECAUTIONS
Kinks or sharp bends in the refrigerant tubing or
hoses will reduce the capacity of the entire system.
High pressures are produced in the system when it is
operating. Extreme care must be exercised to make
sure that all connections are pressure tight. Dirt and
moisture can enter the system when it is opened for
repair.
A good rule for the flexible hose lines is to keep the
radius of all bends at least 10 times the diameter of
the hose. Sharp bends will reduce the flow of refrig-
erant. The flexible hose lines should be routed so
they are at least 80 mm (3 inches) from the exhaust
manifold. It is a good practice to inspect all flexible
hose lines at least once a year to make sure they are
in good condition and properly routed.
24 - 10 HEATING AND AIR CONDITIONINGJ

DOOR REMOVAL/INSTALLATIONÐXJ.....23-35
DOOR RESTRAINT REPLACEMENTÐXJ . . . 23-41
DOOR SERVICEÐYJ, FULL-METAL......23-142
DOOR SPACER BLOCKSÐTWO-DOOR
VEHICLES, FRONT....................23-53
DOOR STATIONARY WINDOW
GLASSÐXJ, REAR...................23-46
DOOR TRIM PANELÐXJ...............23-31
DOOR TRIM PANELÐYJ, FULL-METAL . . . 23-137
DOOR VACUUM MOTOR, FRESH AIR.....24-34
DOOR VACUUM MOTOR REPLACEMENT,
A/C RECIRCULATING..................24-27
DOOR VENT WINDOW GLASSÐYJ,
FULL-METAL.......................23-137
DOOR WATERDAMÐYJ, FULL-METAL . . . 23-137
DOOR WEATHERSTRIP SEAL
REPLACEMENTÐYJ.................23-142
DOOR WEATHERSTRIP SEALSÐYJ,
FULL-METAL.......................23-141
DOOR WINDOW EXTERIOR
MOLDINGSÐXJ.....................23-54
DOOR WINDOW GLASS AND DOOR
OPENING WEATHERSTRIP SEALSÐXJ....23-55
DOOR WINDOW GLASS REGULATOR
HANDLEÐYJ, FULL-METAL............23-136
DOOR WINDOW GLASS REGULATORÐ
XJ, FRONT..........................23-42
DOOR WINDOW GLASS REGULATORÐ
XJ, REAR...........................23-44
DOOR WINDOW GLASS REGULATORÐ
YJ, FULL-METAL....................23-138
DOOR WINDOW GLASSÐXJ, FRONT.....23-43
DOOR WINDOW GLASSÐXJ, REAR......23-45
DOOR WINDOW GLASSÐYJ, FULL-
METAL............................23-139
DOORÐYJ, HALF-METAL SOFT TOP.....23-134
DOUBLE CARDAN (CV)................16-11
DRAG LINK....................19-16,19-20
DRAINING COOLING SYSTEM............7-21
DRAW FUSE, IGNITION-OFF.............8F-1
DRAW, IGNITION-OFF.................8A-10
DRB SCAN TOOL; BRAKES...............5-3
DRB SCAN TOOL; COOLING SYSTEM.......7-5
DRB SCAN TOOL; EMISSION CONTROL
SYSTEMS...........................25-2
DRB SCAN TOOL; FUEL SYSTEM........14-54
DRB SCAN TOOL; IGNITION SYSTEMS....8D-8
DRIERÐ2.5L ENGINES, CONDENSER
FILTER.............................24-27
DRIERÐ4.0L ENGINES, FILTER.........24-28
DRIP RAIL MOLDINGÐXJ.............23-25
DRIVE (4WD) SWITCH, FOUR-WHEEL;
INSTRUMENT CLUSTER (XJ-RHD).....8W-40-2
DRIVE (4WD) SWITCH, FOUR-WHEEL;
TRANSMISSION CONTROLS (XJ-RHD) . . 8W-31-1
DRIVE, AUTOMATIC BELT TENSIONERÐ
XJ MODELS WITH RIGHT HAND..........7-42
DRIVE AXLE ASSEMBLY
REPLACEMENTÐXJ VEHICLES; FRONT
SUSPENSION AND AXLE................2-23
DRIVE AXLE ASSEMBLY
REPLACEMENTÐXJ VEHICLES; REAR
SUSPENSION AND AXLES...........3-14,3-31
DRIVE AXLE ASSEMBLY
REPLACEMENTÐYJ VEHICLES; FRONT
SUSPENSION AND AXLE................2-24
DRIVE AXLE ASSEMBLY
REPLACEMENTÐYJ VEHICLES; REAR
SUSPENSION AND AXLES
...............3-14
DRIVE AXLE, FRONT
....................2-3
DRIVE BELT, ACCESSORY
...............0-21
DRIVE BELT DIAGNOSIS (CONT.),
SERPENTINE
.........................7-40
DRIVE BELT DIAGNOSIS, SERPENTINE
.....7-39
DRIVE, BELT SERVICEÐEXCEPT RIGHT
HAND
...............................7-40
DRIVE, BELT SERVICEÐXJ MODELS
WITH RIGHT HAND
....................7-42
DRIVE BELT TENSION
..................7-45
DRIVE BELTS, ENGINE ACCESSORY
.......7-38
DRIVE GEAR, SPEED SENSOR
ROTORÐSPEEDOMETER
.............21-193
DRIVE, GENERATOR REMOVE/INSTALLÐ
LEFT-HAND
..........................8B-6
DRIVE, GENERATOR REMOVE/INSTALLÐ
RIGHT-HAND
.........................8B-7
DRIVE PULLEY REPLACEMENT
..........19-13DRIVE (RHD), BELT TENSIONÐEXCEPT
RIGHT HAND.........................7-38
DRIVE (RHD), BELT TENSIONÐRIGHT
HAND...............................7-38
DRIVE (RHD) MODELS, BELT TENSIONÐ
EXCEPT RIGHT HAND..................7-45
DRIVE SHAFTS.......................0-26
DRIVE VEHICLES, RIGHT HAND..........23-1
DRIVE, VISCOUS FAN..................7-34
DRIVELINE SNAP; FRONT SUSPENSION
AND AXLE...........................2-19
DRIVELINE SNAP; REAR SUSPENSION
AND AXLES..........................3-10
DRIVELINE VIBRATION.................16-3
DRIVER'S DOOR JAMB SWITCH.....8U-1,8U-2
DRIVER'S POWER LOCK SWITCHÐ2-
DOOR (LHD).........................8P-3
DRIVER'S POWER LOCK SWITCHÐ2-
DOOR (RHD).........................8P-4
DRIVER'S POWER LOCK SWITCHÐ4-
DOOR..............................8P-5
DRIVER'S POWER WINDOW SWITCHÐ
2-DOOR (LHD).......................8S-4
DRIVER'S POWER WINDOW SWITCHÐ
2-DOOR (RHD).......................8S-5
DRIVER'S POWER WINDOW SWITCHÐ
4-DOOR.............................8S-3
DRIVER'S SEAT BELT SWITCH.......8U-1,8U-3
DRIVETRAIN.........................0-22
DRL MODULE REPLACEMENTÐXJ.......8L-15
DRL MODULE REPLACEMENTÐYJ........8L-30
DRUM BRAKE ADJUSTMENT............5-57
DRUM BRAKES.......................5-55
DRUM BRAKESHOE INSTALLATION.......5-55
DRUM BRAKESHOE REMOVAL...........5-55
DRUM REFINISHING, BRAKE............5-58
DRUMÐREAR SUPPORT OVERHAUL,
OVERRUNNING CLUTCHÐLOW-
REVERSE..........................21-125
DUCT, DEFROSTER NOZZLE............24-33
DUCT, FRESH AIR INTAKE..............24-34
ECU AND HCU DIAGNOSIS, ANTILOCK......5-3
ECU INSTALLATION (XJ MODELS)........5-40
ECU OPERATION......................5-37
ECU REMOVAL (XJ MODELS)............5-40
ECU REMOVAL/INSTALLATION (YJ
MODELS)............................5-41
EDGE GUARD/EDGE PROTECTOR
STRIPÐXJ, DOOR....................23-54
EFFECTS OF INCORRECT FLUID LEVEL....21-71
EFFORT, HARD PEDAL OR HIGH PEDAL.....5-6
ELECTRIC COOLING FANÐXJ MODELS
WITH 4.0L 6-CYLINDER ENGINE,
AUXILIARY..........................7-35
ELECTRICAL CONTROL, FUEL PUMP......14-5
ELECTRONIC CONTROL UNIT (ECU).......5-34
ELECTROSTATIC DISCHARGE (ESD)
SENSITIVE DEVICES; WIRING
DIAGRAMSÐGENERAL INFORMATION
(XJ)...............................8W-2
ELEMENT, AIR CLEANER; EMISSION
CONTROL SYSTEMS...................25-7
ELEMENT, AIR CLEANER; FUEL SYSTEM . . 14-59
ELEMENT, AIR CLEANER; LUBRICATION
AND MAINTENANCE...................0-18
ELEMENT TEST, OXYGEN SENSOR (O2S)
HEATING...........................14-48
ELEMENTS, HEATER; POWER MIRRORS
(XJ-RHD).........................8W-62-1
EMISSION CONTROL INFORMATION
(VECI) LABEL, VEHICLE.................25-1
EMISSION CONTROL SYSTEM...........0-20
EMISSION CONTROL SYSTEM
MAINTENANCE........................0-4
EMISSION CONTROLS..................25-4
EMR LAMPÐPCM OUTPUT............14-27
ENGINE ACCESSORY DRIVE BELTS.......7-38
ENGINE AND TRANSMISSION/TRANSFER
CASE IDENTIFICATION...............Intro.-5
ENGINE ASSEMBLY (SHORT BLOCK),
SERVICE.............................9-4
ENGINE ASSEMBLYÐXJ VEHICLES
. . . 9-18,9-59
ENGINE ASSEMBLYÐYJ VEHICLES
. . . 9-20,9-62
ENGINE, AUXILIARY ELECTRIC COOLING
FANÐXJ MODELS WITH 4.0L
6-CYLINDER
.........................7-35
ENGINE BLOCK HEATER
................7-44
ENGINE BREAK-IN
.....................0-15ENGINE COOLANT TEMPERATURE
GAUGE; INSTRUMENT CLUSTER (XJ) . . 8W-40-1
ENGINE COOLANT TEMPERATURE
SENSOR; FUEL SYSTEM...............14-60
ENGINE COOLANT TEMPERATURE
SENSOR; FUEL/IGNITION (XJ)........8W-30-3
ENGINE COOLANT TEMPERATURE
SENSOR; FUEL/IGNITION (YJ)........8W-30-3
ENGINE COOLANT TEMPERATURE
SENSOR; IGNITION SYSTEMS......8D-19,8D-5
ENGINE COOLANT TEMPERATURE
SENSOR; FUEL/IGNITION (XJ-RHD)....8W-30-3
ENGINE COOLANT TEMPERATURE
SENSOR TEST; FUEL SYSTEM..........14-46
ENGINE COOLANT TEMPERATURE
SENSOR TEST; IGNITION SYSTEMS.......8D-9
ENGINE COOLANT TEMPERATURE
SENSORÐPCM INPUT................14-23
ENGINE COOLANT TEMPERATURE
WARNING LAMP; INSTRUMENT
CLUSTER (XJ).....................8W-40-1
ENGINE COOLANT TEMPERATURE
WARNING LAMP; INSTRUMENT
CLUSTER (XJ-RHD)................8W-40-1
ENGINE COOLING SYSTEM..............0-18
ENGINE CYLINDER HEAD...........9-25,9-67
ENGINE CYLINDER HEAD COVER.....9-22,9-64
ENGINE CYLINDER HEAD GASKET
FAILURE DIAGNOSIS....................9-5
ENGINE DAMPER.....................9-17
ENGINE DIAGNOSIS....................9-5
ENGINE, DIAGRAM INDEXÐ2.5L;
FUEL/IGNITION (XJ)..................8W-30-6
ENGINE, DIAGRAM INDEXÐ4.0L;
FUEL/IGNITION (XJ)................8W-30-6
ENGINE, ENGINE EXHAUST MANIFOLDÐ
2.5L................................11-7
ENGINE, ENGINE EXHAUST MANIFOLDÐ
4.0L................................11-7
ENGINE, ENGINE FIRING ORDERÐ2.5L
4-CYLINDER........................8D-32
ENGINE, ENGINE FIRING ORDERÐ4.0L
6-CYLINDER........................8D-32
ENGINE EXHAUST MANIFOLDÐ2.5L
ENGINE.............................11-7
ENGINE EXHAUST MANIFOLDÐ4.0L
ENGINE.............................11-7
ENGINE FIRING ORDERÐ2.5L
4-CYLINDER ENGINE.................8D-32
ENGINE FIRING ORDERÐ4.0L
6-CYLINDER ENGINE.................8D-32
ENGINE, INTAKE MANIFOLDÐ2.5L........11-7
ENGINE, INTAKE MANIFOLDÐ4.0L........11-8
ENGINE MAINTENANCE.................0-15
ENGINE MOUNTÐREAR............9-16,9-57
ENGINE MOUNTSÐFRONT..........9-14,9-56
ENGINE OIL..........................0-15
ENGINE OIL CHANGE AND FILTER
REPLACEMENT.......................0-16
ENGINE OIL FILTER....................0-17
ENGINE OIL PRESSURE.................9-7
ENGINE ONLY, POWER STEERING
PRESSURE SWITCHÐ2.5L.............14-63
ENGINE ONLY, TORQUE CONVERTER
CLUTCH (TCC) SOLENOID AND
RELAYÐ2.5L; TRANSMISSION
CONTROLS (XJ)...................8W-31-1
ENGINE ONLY, TRANSMISSION
CONTROL MODULEÐ4.0L;
TRANSMISSION CONTROLS (XJ)......8W-31-1
ENGINE PERFORMANCE.................9-2
ENGINE SERVICE PROCEDURES, 2.5L.....9-13
ENGINE SERVICE PROCEDURES, 4.0L.....9-55
ENGINE SPECIFICATIONS...........9-52,9-93
ENGINE, VACUUM ROUTING
SCHEMATICÐ2.5L 4 CYLINDER..........25-3
ENGINE, VACUUM ROUTING
SCHEMATICÐ4.0L 6 CYLINDER..........25-3
ENGINES, CONDENSER FILTER
DRIERÐ2.5L........................24-27
ENGINES, CONDENSERÐ4.0L..........24-28
ENGINES, FILTER DRIERÐ4.0L
.........24-28
ENGINES, FUEL USAGE STATEMENTÐ
GAS
................................0-19
ENGLISH/SAE CONVERSION, METRIC
. . Intro.-11
ENTRY MODULE, KEYLESS
.........8P-1,8P-7
ENTRY MODULE, REMOTE KEYLESS;
POWER DOOR LOCKS (XJ)
...........8W-61-1
JINDEX 9
Description Group-Page Description Group-Page Description Group-Page