2002 JEEP GRAND CHEROKEE body control module

INSTRUMENT PANEL
STEERING COLUMN SUPPORT
BRACKET
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) Remove the instrument panel plenum bracket
from the steering column support bracket. (Refer to
23 - BODY/INSTRUMENT PANEL/IP PLENUM
BRACKET - REMOVAL).
(4) Remove the three screws that secure the
instrument panel wire harness mounting tabs to the
back of the steering column support bracket.
(5) Remove the two screws that secure the 16-way
data link connector to the instrument panel steering
column support bracket and remove the connector
from the bracket (Fig. 35).
(6) Remove the Junction Block (JB) and Body Con-
trol Module (BCM) unit from the instrument panel
steering column support bracket, but do not discon-
nect any of the instrument panel wire harness con-
nectors from the unit. (Refer to 8 - ELECTRICAL/
POWER DISTRIBUTION/JUNCTION BLOCK -
REMOVAL).
(7) From the face of the instrument panel, remove
the five screws that secure the steering column sup-
port bracket to the instrument panel structural duct.
(8) Remove the steering column support bracket
from the instrument panel structural duct.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERINGCOLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the steering column support bracket to
the instrument panel structural duct.
(2) From the face of the instrument panel, install
and tighten the five screws that secure the steering
column support bracket to the instrument panel
structural duct (Fig. 35). Tighten the screws to 11.8
N´m (105 in. lbs.).
(3) Position the instrument panel wire harness
mounting tabs to the back of the steering column
support bracket.
(4) Install and tighten the three screws that secure
the instrument panel wire harness mounting tabs to
the back of the steering column support bracket.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(5) Reinstall the instrument panel plenum bracket
onto the steering column support bracket. (Refer to
23 - BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL PLENUM BRACKET - INSTALLATION).
(6) Reinstall the Junction Block (JB) and Body
Control Module (BCM) unit onto the instrument
Fig. 35 Instrument Panel Steering Column Support
Bracket Remove/Install
1 - STRUCTURAL DUCT
2 - SCREWS (5)
3 - 16±WAY DATA LINK CONNECTOR
4 - STEERING COLUMN SUPPORT BRACKET
23 - 64 INSTRUMENT PANEL SYSTEMWJ

STEERING COLUMN OPENING
COVER
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse cover from the Junction Block
(JB) and Body Control Module (BCM) unit under the
driver side outboard end of the instrument panel.
(Refer to 8 - ELECTRICAL/POWER DISTRIBU-
TION/FUSE COVER - REMOVAL).
(3) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(4) Remove the one screw that secures the out-
board end of the steering column opening cover to
the U-nut on the outboard end of the instrument
panel top pad (Fig. 39).
(5) Remove the two screws that secure the lower
edge of the steering column opening cover to the
U-nuts on the instrument panel steering column sup-
port bracket.
(6) Pull the steering column opening cover rear-
ward to disengage the three snap clips (one outboard
and two inboard) that secure it to the receptacles in
the instrument panel.
(7) Remove the steering column opening cover
from the instrument panel.
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THISIS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the steering column opening cover
onto the instrument panel (Fig. 39).
(2) Align the three snap clips on the steering col-
umn opening cover with their receptacles in the
instrument panel.
(3) Using hand pressure, press firmly and evenly
on the steering column opening cover over the snap
clip locations until each of the snap clips is fully
engaged in its receptacle.
(4) Install and tighten the two screws that secure
the lower edge of the steering column opening cover
to the instrument panel steering column support
bracket. Tighten the screws to 2.2 N´m (20 in. lbs.).
(5) Install and tighten the one screw that secures
the outboard end of the steering column opening
cover to the U-nut on the outboard end of the instru-
ment panel top pad. Tighten the screw to 2.2 N´m (20
in. lbs.).
(6) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(7) Reinstall the fuse cover onto the Junction
Block (JB) and Body Control Module (BCM) unit
under the driver side outboard end of the instrument
panel. (Refer to 8 - ELECTRICAL/POWER DISTRI-
BUTION/FUSE COVER - INSTALLATION).
(8) Reconnect the battery negative cable.
Fig. 39 Steering Column Opening Cover Remove/
Install
1 - INSTRUMENT PANEL TOP PAD
2 - STEERING COLUMN OPENING COVER
3 - SCREW (3)
23 - 68 INSTRUMENT PANEL SYSTEMWJ

SUNROOF
TABLE OF CONTENTS
page page
SUNROOF
DESCRIPTION.........................96
DIAGNOSIS AND TESTING - SUNROOF......96
DRAIN TUBE
REMOVAL............................100
INSTALLATION........................100
CONTROL MODULE
REMOVAL............................101
INSTALLATION........................101
DRIVE MOTOR
REMOVAL............................101
INSTALLATION........................101
WIND DEFLECTOR
REMOVAL............................102INSTALLATION........................102
GLASS PANEL
REMOVAL............................102
INSTALLATION........................103
ADJUSTMENTS
ADJUSTMENTS - FIT.................103
ADJUSTMENT - TIMING...............103
SUNSHADE
REMOVAL............................103
INSTALLATION........................103
HOUSING ASSEMBLY
REMOVAL............................104
INSTALLATION........................104
SUNROOF
DESCRIPTION
WARNING: Keep fingers and other body parts out
of sunroof opening at all times.
The sunroof features a power sliding glass panel
and a sunshade which can be manually positioned
anywhere along its travel, rearward of glass panel
front edge.
The sunroof is electrically operated from a switch
located on the mini overhead console. To operate the
sunroof the ignition switch must be in the On/Run
position. The sunroof has both manual and Express
Open modes of operation when opening. To open the
sunroof in the Express Open mode, the switch is
pressed rearward for less than1 second.This causes
the sunroof glass to automatically retract and stop at
a position slightly forward of full open that reduces
low speed wind buffeting. The sunroof can also be
opened manually by pressing and holding the switch
rearward. Once the switch is held reward for more
than1 second,the glass will retract in the manual
mode. Releasing the switch at any time during travel
will cause the sunroof to stop at the current position.
To close the sunroof from an open position, the
switch must be pushed forward and held until the
sunroof glass comes to a complete stop. Releasing the
switch at any time in this mode will cause the sun-
roof to stop at the current position.
To vent the sunroof from the closed position, the
switch is pushed forward and held. Releasing theswitch at any time during travel will cause the sun-
roof to stop at the current vent position. To reach the
fully vented position, continue to hold the switch for-
ward until vent motion stops. To close the sunroof
from the vent position, push and hold the switch
rearward until the glass comes to a complete stop.
DIAGNOSIS AND TESTING - SUNROOF
CAUTION: The sunroof motor is only to be powered
through the vehicle battery and vehicle wire har-
ness. Applying power to the sunroof motor leads
will cause failure of the sunroof control unit.
Before beginning sunroof diagnostics verify that all
other power accessories are in proper operating con-
dition. Refer to Sunroof Diagnostic Chart for possible
causes. If not, a common electrical problem may
exist. Refer to Group 8W, Wiring Diagrams, of this
publication for circuit, splice and component descrip-
tions. Check the condition of the circuit protection
(20 amp high current fuse (battery feed) located in
the Power Distribution Center (PDC). Check the
cover of the PDC for location of the fuse. Check for
correct operation of the sunroof delay relay. Inspect
all wiring connector pins for proper engagement and
continuity. Check for battery voltage at battery and
ignition pins of the power sunroof express module
wiring connector. Refer to Group 8W, Wiring Dia-
grams, for circuit information. The controller will not
operate at less than 10 volts. Check the ground at
the sunroof express module.
Before beginning diagnosis for wind noise or water
leaks, verify that the problem was not caused by
23 - 96 SUNROOFWJ

CONTROL MODULE
REMOVAL
(1) Move the glass panel to the fully closed posi-
tion.
(2) Remove the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - REMOVAL)
(3) Remove the sun visors. (Refer to 23 - BODY/
INTERIOR/SUN VISOR - REMOVAL)
(4) Remove the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - REMOVAL)
(5) Lower headliner as necessary to gain access to
the sunroof express module.
(6) Disconnect the express module wire harness
connectors.
(7) Remove express module screw.
(8) Remove express module from the keyway by
sliding module towards the center of the vehicle.
INSTALLATION
(1) Insert sunroof express module in the keyway
located in the sunroof module and slide the module
outward to lock it into position.
(2) Install the sunroof express module screw.
(3) Connect the wire connectors to the sunroof
express module.
(4) Install the headliner into position.
(5) Install the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION)
(6) Install the sun visors. (Refer to 23 - BODY/IN-
TERIOR/SUN VISOR - INSTALLATION)
(7) Install the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - INSTALLATION)
(8) Test sunroof operation, adjust if necessary.
(Refer to 23 - BODY/SUNROOF/GLASS PANEL -
ADJUSTMENTS)
DRIVE MOTOR
REMOVAL
CAUTION: The sunroof system is timed from the
factory so that the motor shuts off automatically
when the sunroof window reaches a certain posi-
tion. Extreme care must be taken when removing
the motor, timing may be thrown off causing possi-
ble damage to the sunroof system. Anytime the
motor is removed from the sunroof assembly the
sunroof glass panel must be in the FULLY CLOSED
POSITION or the unit will be out of timing. The drive
motor cannot be reset to the park position after
being removed.CAUTION: The sunroof motor should only be pow-
ered through the vehicle battery and sunroof wire
harness. Applying power to the sunroof motor leads
will cause failure of the control module.
(1) Move glass panel to the fully closed position.
(2) Remove the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - REMOVAL)
(3) Remove the B-pillar upper trim. (Refer to 23 -
BODY/INTERIOR/B-PILLAR UPPER TRIM -
REMOVAL)
(4) Remove the C-pillar trim. (Refer to 23 - BODY/
INTERIOR/C-PILLAR TRIM - REMOVAL)
(5) Remove the D-pillar trim. (Refer to 23 - BODY/
INTERIOR/D-PILLAR TRIM - REMOVAL)
(6) Remove the sunvisors. (Refer to 23 - BODY/IN-
TERIOR/SUN VISOR - REMOVAL)
(7) Remove the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - REMOVAL)
(8) Disconnect the control switch wire connector.
(9) Remove headliner as necessary to gain access
to sunroof drive motor. Refer to Headliner Removal
and Installation for proper procedures.
(10) Disconnect the drive motor wire harness con-
nectors (Fig. 3).
(11) Remove drive motor fasteners and remove
motor from the sunroof housing.
INSTALLATION
(1) Ensure that the window is in the fully closed
position before mounting the motor. If motor fails
with the window in the open position the sunroof
glass panel timing will have to be timed. The new
motor comes in the fully closed position and with a
gage for setting cable timing. (Refer to 23 - BODY/
SUNROOF/GLASS PANEL - ADJUSTMENTS - TIM-
ING)
(2) Place drive motor into position on the sunroof
housing and install fasteners.
Fig. 3 Sunroof Drive Motor and Express Module
1 - EXPRESS MODULE
2 - SCREW
WJSUNROOF 23 - 101

(3) Connect express module, drive motor, and con-
trol switch wire connectors.
(4) Set headliner into position.
(5) Test sunroof operation, adjust as necessary.
(Refer to 23 - BODY/SUNROOF/GLASS PANEL -
ADJUSTMENTS)
(6) Finish installing the headliner.
(7) Connect the control switch wire connector.
(8) Install the overhead console. (Refer to 8 -
ELECTRICAL/OVERHEAD CONSOLE - INSTALLA-
TION)
(9) Install the sunvisors. (Refer to 23 - BODY/IN-
TERIOR/SUN VISOR - INSTALLATION)
(10) Install the D-pillar trim. (Refer to 23 - BODY/
INTERIOR/D-PILLAR TRIM - INSTALLATION)
(11) Install the C-pillar trim. (Refer to 23 - BODY/
INTERIOR/C-PILLAR TRIM - INSTALLATION)
(12) Install the B-pillar upper trim. (Refer to 23 -
BODY/INTERIOR/B-PILLAR UPPER TRIM -
INSTALLATION)
(13) Install the A-pillar trim. (Refer to 23 - BODY/
INTERIOR/A-PILLAR TRIM - INSTALLATION)
WIND DEFLECTOR
REMOVAL
(1) Open sunroof glass panel.
(2) Push down one corner of the wind deflector and
let the other corner rise up (Fig. 4).
(3) Push the low corner towards the opposite side
of the vehicle until tab on sunshade clears the body.
Then raise the corner up.
(4) Repeat the procedure to the other corner.
(5) Lift wind deflector to 90% of the way.
(6) Push the attaching ends of the deflector to the
rear of the vehicle to disengage the deflector.
INSTALLATION
(1) Place wind deflector at 90% in the vertical posi-
tion to the sunroof. With the sunroof open.
(2) Push ends of the deflector towards the front of
the vehicle to engage ends.
(3) Lower wind deflector to normal position.
(4) Push one corner to the opposite side of the
vehicle until tab clears vehicle body and lower deflec-
tor for that corner.
(5) Push the side that was just installed com-
pletely down.
(6) Push the opposite corner cross vehicle until tab
clears the body. Then lower deflector to position.
(7) Test sunroof operation.
GLASS PANEL
REMOVAL
(1) Slide sunshade rearward to the open position.
(2) Move the glass panel to the fully closed posi-
tion.
(3) Remove the four attaching screws (Fig. 5).
(4) Lift off glass panel and remove from vehicle.
Fig. 4 Wind Deflector
1 - WIND DEFLECTOR
2-TAB
Fig. 5 Sunroof Glass Panel Removal
1 - ATTACHING SCREW
23 - 102 SUNROOFWJ
DRIVE MOTOR (Continued)

OPERATION
OPERATION - HEATER AND AIR CONDITIONER
Outside fresh air enters the vehicle through the
cowl top opening at the base of the windshield, and
passes through a plenum chamber to the HVAC sys-
tem blower housing. Air flow velocity can then be
adjusted with the blower motor speed selector switch
on the a/c heater control panel. The air intake open-
ings must be kept free of snow, ice, leaves, and other
obstructions for the HVAC system to receive a suffi-
cient volume of outside air.
It is also important to keep the air intake openings
clear of debris because leaf particles and other debris
that is small enough to pass through the cowl ple-
num screen can accumulate within the HVAC hous-
ing. The closed, warm, damp and dark environment
created within the HVAC housing is ideal for the
growth of certain molds, mildews and other fungi.
Any accumulation of decaying plant matter provides
an additional food source for fungal spores, which
enter the housing with the fresh air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during HVAC sys-
tem operation.
Both the manual and AZC heater and air condi-
tioner are blend-air type systems. In a blend-air sys-
tem, a blend door controls the amount of
unconditioned air (or cooled air from the evaporator)
that is allowed to flow through, or around, the heater
core. A temperature control knob on the a/c heater
control panel determines the discharge air tempera-
ture by energizing the blend door actuator, which
operates the blend door. This allows an almost imme-
diate control of the output air temperature of the sys-
tem. The AZC system will have separate blend doors
and temperature controls for each front seat occu-
pant.
The mode control knob on the a/c heater control
panel is used to direct the conditioned air to the
selected system outlets. On manual temperature con-
trol systems, the mode control knob switches engine
vacuum to control the mode doors, which are oper-
ated by vacuum actuators. On AZC systems, the
mode control knob switches electrical current to con-
trol the mode doors, which are operated by electronic
actuators.
The outside air intake can be shut off on manual
temperature control systems by selecting the Recircu-
lation Mode with the mode control knob. The outside
air intake can be shut off on Automatic Zone Control
(AZC) type system by pushing the Recirculation
Mode button. This will operate the recirculation door
that closes off the outside fresh air intake and recir-
culates the air that is already inside the vehicle.The air conditioner for all models is designed for
the use of non-CFC, R-134a refrigerant. The air con-
ditioning system has an evaporator to cool and dehu-
midify the incoming air prior to blending it with the
heated air. This air conditioning system uses a ther-
mal expansion valve to meter refrigerant flow to the
evaporator coil. To maintain minimum evaporator
temperature and prevent evaporator freezing, the
system utilizes an evaporator thermister probe with
the appropriate operating logic located in the body
control module (BCM).
OPERATION - REFRIGERANT SYSTEM SERVICE
PORT
The high pressure service port is located on the liq-
uid line near the receiver/drier. The low pressure ser-
vice port is located on the suction line near the
evaporator at the rear of the engine compartment.
Each of the service ports has a threaded plastic
protective cap installed over it from the factory. After
servicing the refrigerant system, always reinstall
both of the service port caps.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
PERFORMANCE
The air conditioning system is designed to provide
the passenger compartment with low temperature
and low specific humidity air. The evaporator, located
in the HVAC housing on the dash panel below the
instrument panel, is cooled to temperatures near the
freezing point. As warm damp air passes through the
cooled evaporator, the air transfers its heat to the
refrigerant in the evaporator and the moisture in the
air condenses on the evaporator fins. During periods
of high heat and humidity, an air conditioning sys-
tem will be more effective in the Recirculation Mode.
With the system in the Recirculation Mode, only air
from the passenger compartment passes through the
evaporator. As the passenger compartment air dehu-
midifies, the air conditioning system performance
levels improve.
Humidity has an important bearing on the tempera-
ture of the air delivered to the interior of the vehicle. It
is important to understand the effect that humidity has
on the performance of the air conditioning system.
When humidity is high, the evaporator has to perform a
double duty. It must lower the air temperature, and it
must lower the temperature of the moisture in the air
that condenses on the evaporator fins. Condensing the
moisture in the air transfers heat energy into the evap-
orator fins and tubing. This reduces the amount of heat
the evaporator can absorb from the air. High humidity
greatly reduces the ability of the evaporator to lower
the temperature of the air.
24 - 2 HEATING & AIR CONDITIONINGWJ
HEATING & AIR CONDITIONING (Continued)

A/C COMPRESSOR CLUTCH
DESCRIPTION
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a hub bearing and pul-
ley assembly, and a clutch plate (Fig. 4). The
electromagnetic coil unit and the hub bearing and
pulley assembly are each retained on the nose of the
compressor front housing with snap rings. The clutch
plate is keyed to the compressor shaft and secured
with a bolt.
OPERATION
The compressor clutch components provide the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley. The compressor clutch and coil are
the only serviced parts on the compressor.
The compressor clutch engagement is controlled by
several components: the a/c switch on the a/c heater
control panel, the Automatic Zone Control (AZC) con-
trol module (if the vehicle is so equipped), the evap-
orator probe, the a/c high pressure transducer, the
a/c compressor clutch relay, the body control module
(BCM) and the Powertrain Control Module (PCM).
The PCM may delay compressor clutch engagement
for up to thirty seconds. Refer to Electronic Control
Modules for more information on the PCM controls.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, refer to the
appropriate wiring diagrams. The battery must be
fully-charged before performing the following tests.
Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the a/c heater mode control switch in any
a/c mode, the a/c heater control a/c switch in the ON
position, and the blower motor switch in the lowest
speed position, start the engine and run it at normal
idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRBIIItscan tool and the appro-
priate diagnostic information for testing of the com-
pressor clutch circuit. The following components
must be checked and repaired as required before you
can complete testing of the clutch coil:
²Fuses in the junction block and the Power Dis-
tribution Center (PDC)
²A/C heater mode control switch
²A/C compressor clutch relay
²A/C high pressure transducer
²A/C evaporator probe
²Powertrain Control Module (PCM)
²Body Control Module (BCM)
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is 2.0 to 3.9
amperes with the electrical system voltage at 11.5 to
12.5 volts. This should only be checked with the work
area temperature at 21É C (70É F). If system voltage
is more than 12.5 volts, add electrical loads by turn-
ing on electrical accessories until the system voltage
drops below 12.5 volts.
(a) If the clutch coil current reading is four
amperes or more, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
Fig. 4 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - SHAFT KEY
3 - PULLEY
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
WJCONTROLS 24 - 13

controlled vehicle accessories during periods of low
engine vacuum such as when the vehicle is climbing
a steep grade, or under other high engine load oper-
ating conditions.
The vacuum reservoir cannot be repaired and, if
faulty or damaged, it must be replaced.
REMOVAL
(1) Remove the right side headlamp mounting
module and headlamp assembly. Refer to Lamps/
Lighting for the procedures.
(2) Remove the two screws that secure the vacuum
reservoir to the base of the radiator closure panel.
(3) Remove the vacuum reservoir.
INSTALLATION
(1) Install the vacuum reservoir in the vehicle and
tighten the two screws to 3.4 N´m (30 in. lbs.).
(2) Install the right side headlamp mounting mod-
ule and headlamp assembly. Refer to Lamps/Lighting
for the procedures.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator probe is a 2 wire temperature sens-
ing element located at the coldest point on the face of
the evaporator. The switch is attached to the evapo-
rator coil fins. The evaporator temperature probe
prevents condensate water on the evaporator coil
from freezing and obstructing A/C system air flow.
OPERATION
The probe is used to switch the clutch OFF before
evaporator freeze-up occurs. Output from the probe is
sampled by the Body Control Module (BCM). The
clutch is switched OFF when the probe temperature
reaches 1.1É C (34É F). It is allowed to switch ON
when the probe temperature reaches 2.2É C (36É F).
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the HVAC housing from the vehi-
cle(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(3) Disassemble the HVAC housing(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - DISASSEMBLY).
(4) Carefully pull the probe out of the evaporator
core.
INSTALLATION
(1) Install the new probe into the evaporator.
NOTE: The new probe must not go into the same
hole (in the evaporator core) that the old probe was
removed from.
(2) Reassemble the HVAC housing(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - ASSEMBLY).
(3) Reinstall the HVAC assembly in the vehicle(Re-
fer to 24 - HEATING & AIR CONDITIONING/DIS-
TRIBUTION/HVAC HOUSING - INSTALLATION).
(4) Reconnect the battery negative cable.
Fig. 22 VACUUM RESERVOIR
1 - FAN RELAY
2 - SPEED CONTROL SERVO
3 - VACUUM RESERVOIR
WJCONTROLS 24 - 35
VACUUM RESERVOIR (Continued)