2002 JEEP GRAND CHEROKEE sensor

REMOVAL
(1) Shift transfer case into NEUTRAL.
(2) Raise vehicle.
(3) Remove transfer case drain plug and drain
transfer case lubricant.
(4) Mark front and rear propeller shaft yokes for
alignment reference.
(5) Support transmission with jack stand.
(6) Remove rear crossmember and skid plate, if
equipped (Fig. 3).
(7) Disconnect front/rear propeller shafts at trans-
fer case. (Refer to 3 - DIFFERENTIAL & DRIV-
ELINE/PROPELLER SHAFT/PROPELLER SHAFT -
REMOVAL)
(8) Disconnect transfer case cable from range
lever.
(9) Disconnect transfer case vent hose (Fig. 4) and
transfer case position sensor.
(10) Support transfer case with transmission jack.
(11) Secure transfer case to jack with chains.
(12) Remove nuts attaching transfer case to trans-
mission.(13) Pull transfer case and jack rearward to disen-
gage transfer case.
(14) Remove transfer case from under vehicle.
DISASSEMBLY
REAR RETAINER - NV242LD
(1) Remove output shaft boot. Spread band clamp
that secures boot on slinger with a suitable awl.
Then slide boot off shaft (Fig. 5).
Fig. 3 Crossmember Removal
1 - CROSSMEMBER
2 - REAR TRANSMISSION MOUNT
Fig. 4 Transfer Case Mounting
1 - NV242 TRANSFER CASE
Fig. 5 Output Boot - Typical
1 - SLINGER
2 - BOOT
3-AWL
4 - TRANSFER CASE
21 - 282 TRANSFER CASE - NV242WJ
TRANSFER CASE - NV242 (Continued)

COMPANION FLANGE AND RANGE LEVER
(1) Remove transfer case position sensor (Fig. 19).
(2) Install two bolts (Fig. 20) partially into the pro-
pellor shaft companion flange, 180É from each other.
(3) Install the rectangular end of the Flange
Holder C-3281 over the bolts to hold the companion
flange stationary and remove the nut holding the
companion flange to the output shaft.
(4) Use Remover C-452 (Fig. 21) to remove the
companion flange.(5) Remove seal washer from front output shaft.
Discard washer as it should not be reused.
(6) Remove the bolt (Fig. 22) that attaches the
range lever to sector shaft. Then move sector to neu-
tral position and remove range lever from shaft.
NOTE: Be sure to note the orientation of the range
lever (lever up or down) so that it may be re-in-
stalled in the same direction.
Fig. 19 Remove Transfer Case Position Sensor
1 - TRANSFER CASE POSITION SENSOR
2 - TRANSFER CASE
Fig. 20 Hold Companion Flange - Typical
1 - HOLDER C-3281
2 - BOLTS
3 - COMPANION FLANGE
Fig. 21 Remove Companion Flange - Typical
1 - TRANSFER CASE
2 - COMPANION FLANGE
3 - REMOVER C-452
Fig. 22 Remove Shift Lever Bolt - Typical
1 - RANGE LEVER
2 - RANGE LEVER BOLT
3 - TRANSFER CASE
21 - 286 TRANSFER CASE - NV242WJ
TRANSFER CASE - NV242 (Continued)

NV242HD REAR RETAINER
(1) Apply bead of MopartSealer, or LoctiteŸ
Ultra Gray, to mating surface of rear retainer. Sealer
bead should be a maximum of 3/16 in.
(2) Install rear retainer on rear case. Tighten
retainer bolts to 20-27 N´m (15-20 ft. lbs.) torque.
(3) Install new output shaft bearing snap-ring
(Fig. 91). Lift mainshaft slightly to seat snap-ring in
shaft groove, if necessary.
(4) Apply 3 mm (1/8 in.) wide bead of Mopartgas-
ket maker or silicone adhesive sealer to mounting
surface of extension housing. Allow sealer to set-up
slightly before proceeding.(5) Install extension housing on rear retainer.
(6) Install extension housing bolts and tighten to
35-46 N´m (26-34 ft. lbs.).
COMPANION FLANGE
(1) Lubricate companion flange hub with transmis-
sion fluid and install flange on front shaft.
(2) Install new seal washer on front shaft.
(3) Install flange on front shaft and tighten nut to
122-176 N´m (90-130 ft. lbs.).
INSTALLATION
(1) Mount transfer case on a transmission jack.
(2) Secure transfer case to jack with chains.
(3) Position transfer case under vehicle.
(4) Align transfer case and transmission shafts
and install transfer case on transmission.
(5) Install and tighten transfer case attaching nuts
to 35 N´m (26 ft. lbs.) torque (Fig. 4).
(6) Align and connect propeller shafts. (Refer to 3 -
DIFFERENTIAL & DRIVELINE/PROPELLER
SHAFT/PROPELLER SHAFT - INSTALLATION)
(7) Fill transfer case with correct fluid. Check
transmission fluid level. Correct as necessary.
(8) Install rear crossmember and skid plate, if
equipped. Tighten crossmember bolts to 41 N´m (30
ft. lbs.) torque.
(9) Remove transmission jack and support stand.
(10) Connect shift rod to transfer case range lever.
(11) Connect transfer case vent hose and transfer
case position sensor.
(12) Adjust transfer case shift cable.
(13) Lower vehicle and verify transfer case shift
operation.
Fig. 91 Install Output Bearing Snap-ring
1 - REAR RETAINER
2 - SNAP-RING
3 - REAR BEARING
WJTRANSFER CASE - NV242 21 - 307
TRANSFER CASE - NV242 (Continued)

POSITION SENSOR
DESCRIPTION
The transfer case position sensor (Fig. 95) is an
electronic device whose output can be interpreted to
indicate the transfer case's current operating mode.
The sensor consists of a five position, resistive multi-
plexed circuit which returns a specific resistance
value to the Powertrain Control Module (PCM) for
each transfer case operating mode. The sensor is
located on the top of the transfer case, just left of the
transfer case centerline and rides against the sector
plate roostercomb. The PCM supplies 5VDC (+/-
0.5V) to the sensor and monitors the return voltage
to determine the sector plate, and therefore the
transfer case, position.
OPERATION
During normal vehicle operation, the Powertrain
Control Module (PCM) monitors the transfer case
position sensor return voltage to determine the oper-
ating mode of the transfer case. Refer to the Operat-
ing Mode Versus Resistance table for the correct
resistance for each position (Fig. 96).
OPERATING MODE VERSUS RESISTANCE
SENSOR POSITION OPERATING MODE SENSOR RESISTANCE (ohms)
1 2WD 1124-1243
2 4WD PART TIME 650-719
3 4WD FULL TIME 389-431
4 NEUTRAL 199-221
5 4WD LOW 57-64
Fig. 96 Position Sensor Linear Movement
1 - POSITION 1 - 10mm  0.5mm
2 - POSITION 2 - 12mm  0.5mm
3 - POSITION 3 - 14mm  0.5mm
4 - POSITION 4 - 16mm  0.5mm
5 - POSITION 5 - 18mm  0.5mm
6 - POSITION 6 - 20mm 0.5mm - FULL EXTENSION
Fig. 95 Transfer Case Position Sensor and
Connector
1 - TRANSFER CASE POSITION SENSOR CONNECTOR
2 - TRANSFER CASE POSITION SENSOR
3 - TRANSFER CASE
4 - OUTPUT SPEED SENSOR CONNECTOR
WJTRANSFER CASE - NV242 21 - 311

REMOVAL
(1) Raise and support the vehicle.
(2) Disengage the transfer case position sensor
connector from the position sensor (Fig. 97).
(3) Remove the position sensor from the transfer
case.
INSTALLATION
(1) Inspect the o-ring seal on the transfer case
position sensor. Replace the o-ring if necessary.
(2) Install the transfer case position sensor into
the transfer case. Torque the sensor to 20-34 N´m
(15-25 ft.lbs.).
(3) Engage the transfer case position sensor con-
nector to the position sensor.
(4) Lower vehicle.
(5) Verify proper sensor operation.
REAR RETAINER BUSHING
AND SEAL - NV242HD
REMOVAL
(1) Raise vehicle.
(2) Remove rear propeller shaft. (Refer to 3 - DIF-
FERENTIAL & DRIVELINE/PROPELLER SHAFT/
PROPELLER SHAFT - REMOVAL)
(3) Using a suitable pry tool or slide-hammer
mounted screw, remove the rear retainer seal.
(4) Using Remover 6957, remove bushing from
rear retainer (Fig. 98).
INSTALLATION
(1) Clean fluid residue from sealing surface and
inspect for defects.
(2) Position replacement bushing in rear retainer
with fluid port in bushing aligned with slot in
retainer.
(3) Using Installer 8160, drive bushing into
retainer until installer seats against case (Fig. 99).
(4) Using Installer C-3995-A, install seal in rear
retainer (Fig. 100).
Fig. 97 Transfer Case Position Sensor and
Connector
1 - TRANSFER CASE POSITION SENSOR CONNECTOR
2 - TRANSFER CASE POSITION SENSOR
3 - TRANSFER CASE
4 - OUTPUT SPEED SENSOR CONNECTOR
Fig. 98 Rear Retainer Bushing Removal
1 - REMOVER 6957
2 - REAR RETAINER BUSHING
Fig. 99 Rear Retainer Bushing Install
1 - REAR RETAINER BUSHING
2 - INSTALLER 8160
21 - 312 TRANSFER CASE - NV242WJ
POSITION SENSOR (Continued)

TIRES/WHEELS
TABLE OF CONTENTS
page page
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND
WHEEL RUNOUT......................1
STANDARD PROCEDURE
STANDARD PROCEDURE - TIRE AND
WHEEL BALANCE......................2
STANDARD PROCEDURE - MATCH
MOUNTING...........................4
STANDARD PROCEDURE - TIRE ROTATION . 5
STANDARD PROCEDURE - WHEEL
INSTALLATION........................5
TIRES
DESCRIPTION
DESCRIPTION - TIRES..................6
DESCRIPTION - RADIAL±PLY TIRES.......6
DESCRIPTION - TIRE INFLATION
PRESSURES..........................6
DESCRIPTION - TIRE PRESSURE FOR
HIGH SPEED..........................7
DESCRIPTION - REPLACEMENT TIRES.....7
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - PRESSURE
GAUGES.............................8
DIAGNOSIS AND TESTING - TREAD WEAR
INDICATORS..........................8
DIAGNOSIS AND TESTING - TIRE WEAR
PATTERNS...........................8
DIAGNOSIS AND TESTING - TIRE NOISE
OR VIBRATION........................8STANDARD PROCEDURE - REPAIRING
LEAKS...............................8
CLEANING.............................9
SPECIFICATIONS
TIRES...............................9
SPECIFICATIONS -.....................9
SPARE TIRE
DESCRIPTION - SPARE / TEMPORARY TIRE . . 10
WHEELS
DESCRIPTION.........................10
DIAGNOSIS AND TESTING - WHEEL
INSPECTION.........................10
STANDARD PROCEDURE - WHEEL
REPLACEMENT.......................10
SPECIFICATIONS
TORQUE CHART......................11
STUDS
REMOVAL.............................11
INSTALLATION.........................11
TIRE PRESSURE MONITORING
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING - TIRE PRESSURE
MONITORING SYSTEM.................12
SENSOR
REMOVAL - TIRE PRESSURE SENSOR/
TRANSMITTER.......................12
INSTALLATION - TIRE PRESSURE SENSOR/
TRANSMITTER.......................13
TIRES/WHEELS
DIAGNOSIS AND TESTING - TIRE AND WHEEL
RUNOUT
Radial runout is the difference between the high
and low points on the tire or wheel (Fig. 1).
Lateral runout is thewobbleof the tire or wheel.
Radial runout of more than 1.5 mm (.060 inch)
measured at the center line of the tread may cause
the vehicle to shake.
Lateral runout of more than 2.0 mm (.080 inch)
measured near the shoulder of the tire may cause the
vehicle to shake.
Sometimes radial runout can be reduced. Relocate
the wheel and tire assembly on the mounting studs
(See Method 1). If this does not reduce runout to an
acceptable level, the tire can be rotated on the wheel.
(See Method 2).
METHOD 1 (RELOCATE WHEEL ON HUB)
(1) Drive vehicle a short distance to eliminate tire
flat spotting from a parked position.
(2) Check wheel bearings and adjust if adjustable
or replace if necessary.
(3) Check the wheel mounting surface.
(4) Relocate wheel on the mounting, two studs
over from the original position.
(5) Tighten wheel nuts until all are properly
torqued, to eliminate brake distortion.
(6) Check radial runout. If still excessive, mark
tire sidewall, wheel, and stud at point of maximum
runout and proceed to Method 2.
METHOD 2 (RELOCATE TIRE ON WHEEL)
NOTE: Rotating the tire on wheel is particularly
effective when there is runout in both tire and
wheel.
WJTIRES/WHEELS 22 - 1

TIRE PRESSURE MONITORING
DESCRIPTION
The EVIC will monitor the tire pressure signals
from the five tire sensors and determine if any tire
has gone below the low pressure threshold or raised
above the high pressure threshold. Refer to the table
below.
LOW TIRE PRESSURE THRESHOLDS
SYSTEM STATUS
INDICATORTIRE PRESSURE
ON 179 kPa (26 PSI)
OFF 214 kPa (31 PSI)
HIGH TIRE PRESSURE THRESHOLDS
SYSTEM STATUS
INDICATORTIRE PRESSURE
ON 310 kPa (45 PSI)
OFF 276 kPa (40 PSI)
The Remote Tire Pressure Monitors (RTPM) are
not internally serviceable. For a Sensor Failure or
Low Battery fault, the RTPM must be replaced.
OPERATION
If equipped with the Tire Pressure Monitoring Sys-
tem, each of the vehicle's five wheels will have a
valve stem with a pressure sensor and radio trans-
mitter built in. Signals from the tire pressure sensors
are received and interpreted by the Electronic Vehi-
cle Information Center (EVIC). A sensor in a
mounted wheel will broadcast its detected pressure
once per minute when the vehicle is moving faster
than 40 km/h (25 mph). The spare tire sensor will
broadcast once every hour. Each sensor's broadcast is
uniquely coded so that the EVIC can determine loca-
tion. The individual tire pressures can be displayed
graphically on the EVIC
DIAGNOSIS AND TESTING - TIRE PRESSURE
MONITORING SYSTEM
All Tire Pressure Monitoring System Faults are
specific to one location. If a9BATTERY LOW9or
9SENSOR FAILURE9fault is detected, the location
will be displayed. The appropriate sensor/transmitter
can then be replaced. If a single sensor/transmitter
cannot be detected by the EVIC, replace that sensor
transmitter. If none of the sensors/transmitters can
be detected, refer to symptoms in the EVIC section.
For additional system description and diagnosis,
refer to Tire Pressure Monitoring in the Body Diag-
nostic manual.
SENSOR
REMOVAL - TIRE PRESSURE SENSOR/
TRANSMITTER
(1) Remove the tire/wheel from the vehicle.
CAUTION: When removing the stick on balancing
weights from the wheel, do not use an abrasive
cleaner or a cleaner which will damage the protec-
tive finish on the wheel.
(2) Remove the balancing weights from the wheel.
NOTE: The cap used on this valve stem contains an
O-ring seal to prevent contamination and moisture
from entering the valve stem. Retain this valve stem
cap for re-use. Do not substitute a regular valve
stem cap in its place.
(3) Remove the cap from the valve stem.
NOTE: The valve stem used on this vehicle is made
of aluminum and the core is nickel plated brass.
The original valve stem core must be reinstalled
and not substituted for a valve stem core made of a
different material. This is required to prevent corro-
sion in the valve stem caused by the different met-
als.
(4) Using the appropriate tool, remove the core
from the valve stem (Fig. 20).
(5) Let the tire fully deflate.
Fig. 20 REMOVING VALVE STEM CORE - TYPICAL
1 - WHEEL
2 - VALVE STEM
3 - TIRE
4 - VALVE STEM CORE TOOL
22 - 12 TIRES/WHEELSWJ

CAUTION: The pressure transmitter must be
removed from the wheel and dropped into the tire
prior to breaking the bead and dismounting the tire.
Failure to do this will greatly increase the risk of
damaging the pressure transducer when servicing
the tire.
(6) Remove nut mounting valve stem of pressure
sensor/transmitter to the wheel (Fig. 21). Drop sen-
sor/transmitter into tire.
CAUTION: When breaking the top and bottom bead
of the tire off the wheel, care must be used so the
bead breaking mechanism on the tire changer does
not damage the wheel. This includes the surface of
the wheel flange on the inside of the wheel.
(7) Using the tire changer manufacturers proce-
dure, first break down the upper bead of the tire.
Then break down the bottom bead of the tire.
CAUTION: When dismounting the upper tire bead
from the wheel, the proper procedure must be used.
Not using the proper procedure will result in dam-
age to the wheel and tire.(8) Dismount the upper bead of the tire from the
wheel.The upper bead must be fully dis-
mounted from the wheel to remove the tire
pressure transmitter from the inside of the tire.
The bottom bead of the tire does not need to be
removed from the wheel.
(9) Pull upward on the tire (Fig. 22). Reach into
the tire and remove the pressure sensor/transmitter
from inside the tire.
INSTALLATION - TIRE PRESSURE SENSOR/
TRANSMITTER
NOTE: When installing the tire pressure sensor/
transmitter, inspect the sealing O-ring at the bottom
of the valve stem for any sign of damage or deteri-
oration. Replace O-ring if necessary, before install-
ing the pressure transmitter on the wheel. Also, be
sure the surface of the wheel that the O-ring seals
against is clean and not damaged.
Fig. 21 VALVE STEM/PRESSURE TRANSMITTER -
TYPICAL
1 - NUT
2 - WHEEL
3 - TIRE
4 - VALVE STEM
Fig. 22 PRESSURE TRANSMITTER REMOVAL -
TYPICAL
1 - TIRE
2 - WHEEL
3 - PRESSURE TRANSMITTER
WJTIRES/WHEELS 22 - 13
SENSOR (Continued)