2002 JEEP GRAND CHEROKEE door op

CURRENT FAULT CODES
System Faults 13 = Mode motor not
responding
14 = AI (Recirc) motor
not responding
15 = Left temperature
door not responding
16 = Right temperature
door not responding
17 = Mode door travel
range too small
18 = Mode door travel
range too large
19 = AI (Recirc) door
travel too small
20 = AI (Recirc) door
travel too large
21 = Left temperature
door travel too small
22 = Left temperature
door travel too large
23 = Right temperature
door travel too small
24 = Right temperature
door travel too large
25 = Calibration check
sum error
26 = Engine coolant temp
bus message missing
27 = Vehicle speed bus
message missing
28 = Engine RPM bus
message missing
29 = OAT bus message
missing
30 = Display intensity bus
message missing
31 = VIN number bus
message missing
32 = Raw OAT bus
message missing
WJCONTROLS 24 - 19
A/C HEATER CONTROL (Continued)

HISTORICAL FAULT CODES
Input faults 33 = IR thermister circuit was open
34 = IR thermister circuit was shorted
35 = Fan pot was shorted
36 = Fan pot was open
37 = Mode pot was shorted
38 = Mode pot was open
39 = IR sensor delta was too large
40 = Reserved
41 = Reserved
42 = One of four motor drivers had drive9A9shorted to
ground
43 = Engine air intake temperature Buss message
missing
44 = Country code Buss message missing
System Faults 45 = Mode motor was not responding
46 = AI (Recirc) motor was not responding
47 = Left temperature door was not responding
48 = Right temperature door was not responding
49 = Mode door travel range too small
50 = Mode door travel range too large
51 = AI (Recirc) door travel range too small
52 = AI (Recirc) door travel range too large
53 = Left temperature door travel too small
54 = Left temperature door travel too large
55 = Right temperature door travel too small
56 = Right temperature door travel too large
57 = Calibration check sum error
58 = Engine coolant temp bus message missing
59 = Vehicle speed bus message missing
60 = Engine RPM bus message missing
61 = OAT bus message missing
62 = Display intensity bus message missing
63 = VIN number bus message missing
64 = Raw OAT bus message was missing
65 = Reserved
66 = Reserved
67 = Reserved
NOTE: A battery disconnect will erase all faults
stored in Random Access Memory (RAM) of the
AZC control module. It is recommended that all
faults be recorded before they are erased.RETRIEVING FAULT CODES
(1) To begin the fault code tests, depress the A/C
and Recirc buttons at the same time and rotate the
left temperature control knob clockwise (CW) one
detent, then release the push-button.
24 - 20 CONTROLSWJ
A/C HEATER CONTROL (Continued)

BLEND DOOR ACTUATOR
DESCRIPTION
The blend door for all models is actuated by an
electric actuator, while the AZC system uses 2 sepa-
rate actuators to allow the driver and passenger to
select individual comfort levels. In the following pro-
cedures, service for both types of actuators is cov-
ered.
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
The blend door actuator is used on all models,
whether equipped with manual or Automatic Zone
Control (AZC). This actuator is located on the front of
the HVAC housing to the right of the floor panel
transmission tunnel, and can be removed from the
passenger compartment without instrument panel or
HVAC housing removal.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the glove box door. Refer to Instrument
Panel System for the procedures.
(3) Remove the lower I/P glove box door surround
panel. Refer to Instrument Panel System for the pro-
cedures.
(4) Unplug the wire harness connector from the
blend door actuator (Fig. 17).
(5) Remove the 2 screws that secure the blend
door actuator to the HVAC housing.
(6) Remove the blend door actuator from the
HVAC housing.
INSTALLATION
(1) Install the blend door actuator on the HVAC
housing and tighten the two mounting screws to 2.2
N´m (20 in. lbs.).
(2) Plug in the wire harness connector to the blend
door actuator.
(3) Install the glove box door. Refer to Instrument
Panel System for the procedures.
(4) Install the lower I/P glove box door surround
panel. Refer to Instrument Panel System for the pro-
cedures.
(5) Connect and the battery negative cable.
MODE DOOR ACTUATOR
DESCRIPTION
The mode door actuators for vehicles equipped with
the standard equipment manual temperature control
system are vacuum controlled. The optional Auto-
matic Zone Control (AZC) system uses electric motors
to actuate all mode doors. The service procedures for
both types of actuators are covered by the following
procedures.
Fig. 17 BLEND DOOR ACTUATOR
1 - BLEND DOOR ACTUATOR
2 - ELECTRICAL CONNECTOR
24 - 30 CONTROLSWJ

REMOVAL
REMOVAL - HEAT/DEFROST - PANEL/DEFROST
DOOR ELECTRIC ACTUATOR
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
These actuators are used only on models equipped
with the optional Automatic Zone Control (AZC) sys-
tem.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the two bolts that secure the center
instrument panel support bracket to the left side of
the floor panel transmission tunnel.
(3) Remove the two bolts that secure the center
instrument panel support bracket to the instrument
panel.
(4) Remove the center instrument panel support
bracket from the vehicle.
(5) Unplug the wire harness connector from the
heat/defrost - panel/defrost door actuator (Fig. 18).
(6) Remove the three screws that secure the heat/
defrost-panel/defrost door motor to the HVAC hous-
ing.
(7) Remove the heat/defrost-panel/defrost door
motor from the HVAC housing.
REMOVAL - HEAT/DEFROST DOOR VACUUM
ACTUATOR
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 PRECAU-
TIONS COULD RESULT IN AN ACCIDENTAL AIRBAG
DEPLOYMENT AND POSSIBLE PERSONAL INJURY.
This actuator is used only on models equipped with
the standard manual temperature control system.
(1) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(2) Unplug the vacuum harness connector from the
heat/defrost door vacuum actuator (Fig. 19).
(3) Disengage the heat/defrost door pivot connec-
tion from the heat/defrost door pivot pin.
(4) Remove the screws that secure the heat/defrost
door vacuum actuator to the HVAC housing.
(5) Remove the heat/defrost door vacuum actuator
from the HVAC housing.
Fig. 18 HEAT/DEFROST - PANEL/DEFROST DOOR
ACTUATOR
1 - LEVER ASSEMBLY
2 - LINKAGE
3 - ELECTRIC ACTUATOR
WJCONTROLS 24 - 31
MODE DOOR ACTUATOR (Continued)

REMOVAL - PANEL/DEFROST DOOR VACUUM
ACTUATOR
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
This actuator is used only on models equipped with
the standard manual temperature control system.
(1) Remove the HVAC housing from the vehicle.
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL)
(2) Unplug the vacuum harness connector from the
heat/defrost door vacuum actuator (Fig. 20).(3) Disengage the panel/defrost door pivot connec-
tion from the panel/defrost door pivot pin.
(4) Remove the screws that secure the panel/de-
frost door vacuum actuator to the HVAC housing.
(5) Remove the panel/defrost door vacuum actuator
from the HVAC housing.INSTALLATION
INSTALLATION - HEAT/DEFROST - PANEL/
DEFROST DOOR ELECTRIC ACTUATOR
(1) Install the heat/defrost-panel/defrost door
actuator on the HVAC housing, and tighten the three
mounting screws to 2.2 N´m (20 in. lbs.).
(2) Plug in the wire harness connector to the heat/
defrost - panel/defrost door actuator.
(3) Install the center instrument panel support
bracket on the vehicle.
(4) Install the two bolts that secure the center
instrument panel support bracket to the instrument
panel.
(5) Install the two bolts that secure the center
instrument panel support bracket to the left side of
the floor panel transmission tunnel.
(6) Connect the battery negative cable.
Fig. 19 MODE DOOR ACTUATORS-MANUAL
SYSTEM
1 - VACUUM LINES
2 - ACTUATING LEVERS
3 - LINKAGE
4 - VACUUM ACTUATORS
5 - ACTUATING LEVER
Fig. 20 PANEL/DEFROST DOOR ACTUATOR
1 - VACUUM LINE
2 - PANEL/DEFROST DOOR ACTUATOR
3 - SHAFT RETAINER
24 - 32 CONTROLSWJ
MODE DOOR ACTUATOR (Continued)

INSTALLATION - HEAT/DEFROST DOOR
VACUUM ACTUATOR
(1) Install the heat/defrost door vacuum actuator
on the HVAC housing and tighten the mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Engage the heat/defrost door pivot connection
with the heat/defrost door pivot pin.
(3) Plug in the vacuum harness connector to the
heat/defrost door vacuum actuator.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
INSTALLATION - PANEL/DEFROST DOOR
VACUUM ACTUATOR
(1) Install the panel/defrost door vacuum actuator
on the HVAC housing and tighten the mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Engage the panel/defrost door pivot connection
with the panel/defrost door pivot pin.
(3) Plug in the vacuum harness connector to the
heat/defrost door vacuum actuator.
(4) Install the HVAC housing in the vehicle. (Refer
to 24 - HEATING & AIR CONDITIONING/DISTRI-
BUTION/HVAC HOUSING - INSTALLATION)
RECIRCULATION DOOR
ACTUATOR
DESCRIPTION
The recirculation door actuator for vehicles
equipped with the standard equipment manual tem-
perature control system is vacuum controlled. The
optional Automatic Zone Control (AZC) system uses
an electric recirculation door actuator. In the follow-
ing procedures, service for both types of actuators is
covered.
REMOVAL
REMOVAL - RECIRCULATION DOOR VACUUM
ACTUATOR
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 AIRBAGSYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
This actuator is used only on models equipped with
the standard manual temperature control system.
(1) Remove the instrument panel from the vehicle.
Refer to Instrument Panel System for the procedures.
(2) Unplug the vacuum harness connector from the
recirculation door vacuum actuator.
(3) Disengage the recirculation door pivot connec-
tion from the door pivot pin.
(4) Disengage the recirculation door actuating rod
from the recirculation door lever.
(5) Remove the screws that secure the recircula-
tion door vacuum actuator to the HVAC housing.
(6) Remove the recirculation door vacuum actuator
from the HVAC housing.
REMOVAL - RECIRCULATION DOOR ELECTRIC
ACTUATOR
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 AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
This actuator is used only on models equipped with
the optional Automatic Zone Control (AZC) system.
(1) Remove the instrument panel from the vehicle.
Refer to Instrument Panel System for the procedures.
(2) Unplug the wire harness connector from the
recirculation door actuator.
(3) Remove the 2 screws securing the recirculation
door housing to the HVAC unit (Fig. 21). Tilt the
front of the housing up while reaching around the
back releasing 2 tangs holding the rear of the hous-
ing down.
(4) Remove the recirculation door housing from the
HVAC unit.
(5) Remove the screws that secure the recircula-
tion door actuator to the HVAC housing.
(6) Remove the recirculation door actuator from
the HVAC housing.
WJCONTROLS 24 - 33
MODE DOOR ACTUATOR (Continued)

INSTALLATION
INSTALLATION - RECIRCULATION DOOR
VACUUM ACTUATOR
(1) Install the recirculation door vacuum actuator
on the HVAC housing and tighten the mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Engage the recirculation door actuating rod
with the recirculation door lever.
(3) Engage the recirculation door pivot connection
with the door pivot pin.
(4) Plug in the vacuum harness connector to the
recirculation door vacuum actuator.
(5) Install the instrument panel in the vehicle.
Refer to Instrument Panel System for the procedures.
INSTALLATION - RECIRCULATION DOOR
ELECTRIC ACTUATOR
(1) Install the recirculation door actuator on the
recirculation door housing and tighten the mounting
screws to 2.2 N´m (20 in. lbs.).
(2) Install the recirculation door housing on the
HVAC unit and tighten the mounting screws to 2.2
N´m (20 in. lbs.).
(3) Plug in the wire harness connector to the recir-
culation door actuator.
(4) Install the instrument panel in the vehicle.
Refer to Instrument Panel System for the procedures.
VACUUM CHECK VALVE
DESCRIPTION
Two vacuum check valves (non AZC only) are
installed on the vacuum supply system. One is on the
accessory vacuum supply line in the engine compart-
ment, near the vacuum tap on the engine intake
manifold. A second vacuum check valve is located on
the bottom of the HVAC unit behind the passenger
front floor duct on the black vacuum line. The vac-
uum check valves are designed to allow vacuum to
flow in only one direction through the accessory vac-
uum supply circuits.
OPERATION
The use of a vacuum check valve helps to maintain
the system vacuum needed to retain the selected A/C
Heater mode settings. The check valve will prevent
the engine from bleeding down system vacuum
through the intake manifold during extended heavy
engine load (low engine vacuum) operation.
The vacuum check valve cannot be repaired and, if
faulty or damaged, it must be replaced.
REMOVAL
(1) Unplug the HVAC vacuum supply line connec-
tor at the vacuum check valve near the engine intake
manifold vacuum adapter fitting.
(2) Note the orientation of the check valve in the
vacuum supply line for correct installation.
(3) Unplug the vacuum check valve from the vac-
uum supply line fittings.
INSTALLATION
(1) Plug in the vacuum check valve at the vacuum
supply line fittings, noting the orientation of the
check valve in the vacuum supply line for correct
installation.
(2) Plug in the HVAC vacuum supply line connec-
tor at the vacuum check valve near the engine intake
manifold vacuum adapter fitting.
VACUUM RESERVOIR
DESCRIPTION
The vacuum reservoir is mounted in the right front
of the vehicle behind the headlamp mounting module
(Fig. 22). The headlamp mounting module and head-
lamp assembly must be removed from the vehicle to
access the vacuum reservoir for service. Refer to
Lamps/Lighting for the procedures.
OPERATION
Engine vacuum is stored in the vacuum reservoir.
The stored vacuum is used to operate the vacuum-
Fig. 21 RECIRCULATION DOOR HOUSING
1 - RECIRCULATION DOOR HOUSING
2 - ATTACHING SCREWS
24 - 34 CONTROLSWJ
RECIRCULATION DOOR ACTUATOR (Continued)

DISTRIBUTION
TABLE OF CONTENTS
page page
AIR OUTLETS
REMOVAL.............................36
INSTALLATION.........................36
BLOWER MOTOR
DESCRIPTION.........................37
OPERATION...........................37
DIAGNOSIS AND TESTING - BLOWER
MOTOR .............................37
REMOVAL.............................37
INSTALLATION.........................38
DEFROSTER DUCTS
REMOVAL.............................38
INSTALLATION.........................39
FLOOR DISTRIBUTION DUCTS
REMOVAL.............................39
INSTALLATION.........................39
INSTRUMENT PANEL DUCTS
REMOVAL.............................39
INSTALLATION.........................39
REAR FLOOR HEAT DUCT
REMOVAL.............................39INSTALLATION.........................39
HVAC HOUSING
REMOVAL.............................41
DISASSEMBLY.........................42
ASSEMBLY............................45
INSTALLATION.........................45
BLEND DOOR
REMOVAL.............................46
INSTALLATION.........................46
MODE DOOR
REMOVAL
REMOVAL - PANEL OUTLET DOOR.......46
REMOVAL - HEAT/DEFROST DOOR.......47
REMOVAL - PANEL/DEFROST DOOR......48
INSTALLATION
INSTALLATION - PANEL OUTLET DOOR....49
INSTALLATION - HEAT/DEFROST DOOR . . . 49
INSTALLATION - PANEL/DEFROST DOOR . . 49
RECIRCULATION DOOR
REMOVAL.............................49
INSTALLATION.........................50
AIR OUTLETS
REMOVAL
The driver side, and passenger side panel outlets
are available for service. The center outlets are only
serviced as part of the instrument cluster center
bezel unit.
(1) Remove the instrument panel top pad from the
instrument panel. Refer to Instrument Panel System
for the procedures.
(2) Remove the two screws that secure each outlet
to the backside of the instrument panel top pad (Fig.
1).
(3) Remove the outlet from the top pad.
INSTALLATION
(1) Fasten the outlet to the top pad. Tighten the
mounting screws to 2.2 N´m (20 in. lbs.).
(2) Install the instrument panel top pad on the
instrument panel. Refer to Instrument Panel System
for the procedures.
Fig. 1 PANEL OUTLETS (PASSENGER SIDE)
1 - MOUNTING SCREWS
2 - MOUNTING SCREWS
3 - PANEL OUTLETS
24 - 36 DISTRIBUTIONWJ