pci bus JEEP GRAND CHEROKEE 2002 WJ / 2.G Workshop Manual

RAIN SENSOR (AUTOWIPE) - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1- -
2 D25 20BK/PK PCI BUS
3- -
4 Z155 20BK/OR GROUND
5 Q30 20BK/LB ACCESSORY DELAY RELAY OUTPUT
6- -
REAR POWER OUTLET - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 A148 16LG/RD FUSED B(+)
2- -
3 Z151 16BK GROUND
REAR WASHER PUMP - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 Z141 18BK GROUND
2 V20 18BK/WT REAR WASHER PUMP MOTOR CONTROL
REAR WIPER MOTOR - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1 Z1 18BK GROUND
2 V13 18BR/LG REAR WIPER MOTOR CONTROL
3 G80 20VT/YL LIFTGATE FLIP-UP AJAR SWITCH SENSE
4 V22 18BR/YL REAR WIPER MOTOR DELAY CONTROL
5 F70 18BK FUSED B(+)
6- -
RECIRCULATION DOOR MOTOR/ACTUATOR (AZC) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
A C32 20GY/DB (LHD) RECIRCULATION DOOR DRIVER (A)
A C100 20YL/DB (RHD) RECIRCULATION DOOR DRIVER (B)
B C100 20YL/DB (LHD) RECIRCULATION DOOR DRIVER (B)
B C32 20GY/DB (RHD) RECIRCULATION DOOR DRIVER (A)
8W - 80 - 112 8W-80 CONNECTOR PIN-OUTWJ

RIGHT SIDE REPEATER LAMP (BUILT-UP-EXPORT) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 L60 18TN RIGHT TURN SIGNAL
2 Z142 18BK GROUND
RIGHT VISOR/VANITY LAMP - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 F70 20PK FUSED B(+)
2 M20 20YL/BK COURTESY LAMP LOAD SHED
SEAT BELT SWITCH - WHITE 2 WAY
CAV CIRCUIT FUNCTION
1 G10 20LG/RD SEAT BELT SWITCH SENSE
2 Z1 20BK GROUND
SEAT MODULE C1 (PREMIUM) - BLACK 20 WAY
CAV CIRCUIT FUNCTION
1 P15 20YL/LB (PREMIUM II/III) SEAT HORIZONTAL FORWARD SWITCH SENSE
2- -
3 P11 20YL/WT(PREMIUM II/III) SEAT REAR UP SWITCH SENSE
4 P43 20GY/LB (PREMIUM II/III) RECLINER UP SWITCH SENSE
5 P19 20YL/LG (PREMIUM II/III) SEAT FRONT UP SWITCH SENSE
6 P86 20DG/YL (PREMIUM I/III) PASSENGER SEAT TEMPERATURE SENSOR INPUT
7 P27 20LB/RD (PREMIUM II/III) REAR RISER POSITION SIGNAL
8 P25 20VT/RD (PREMIUM II/III) SEAT HORIZONTAL POSITION SIGNAL
9 P135 20LB/BK (PREMIUM I/III) DRIVER SEAT TEMPERATURE SENSOR INPUT
10 P28 20BR/RD (PREMIUM II/III) SEAT POSITION SENSOR GROUND
11 P41 20GY/WT (PREMIUM II/III) RECLINER DOWN SWITCH SENSE
12 P17 20RD/YL (PREMIUM II/III) SEAT HORIZONTAL REARWARD SWITCH SENSE
13 - -
14 P21 20RD/LG (PREMIUM II/III) SEAT FRONT DOWN SWITCH SENSE
15 P13 20RD/WT (PREMIUM II/III) SEAT REAR DOWN SWITCH SENSE
16 P47 20LB (PREMIUM II/III) RECLINER POSITION SIGNAL
17 P26 20BR (PREMIUM II/III) FRONT RISER POSITION SIGNAL
18 P29 20BR/WT SEAT SENSOR 5 VOLT SUPPLY
19 Z2 20BK/OR GROUND
20 D25 20VT/YL PCI BUS
8W - 80 - 118 8W-80 CONNECTOR PIN-OUTWJ

SEAT MODULE C2 (PREMIUM) - ORANGE 20 WAY
CAV CIRCUIT FUNCTION
1 F35 16RD FUSED B(+)
2 P131 16BK/OR (PREMIUM I/III) DRIVER SEAT HEATER B(+) DRIVER
3 Z1 16BK GROUND
4 P119 16YL/RD (PREMIUM II/III) SEAT FRONT UP DRIVER
5 P121 16RD/GY (PREMIUM II/III) SEAT FRONT DOWN DRIVER
6 P111 16YL/DB (PREMIUM II/III) SEAT REAR UP DRIVER
7 P113 16RD/BK (PREMIUM II/III) SEAT REAR DOWN DRIVER
8- -
9 P115 16GY/LG (PREMIUM II/III) SEAT HORIZONTAL FORWARD DRIVER
10 F35 16RD FUSED B(+)
11 P130 16DG/WT (PREMIUM I/III) PASSENGER SEAT HEATER B(+) DRIVER
12 Z1 16BK GROUND
13 - -
14 P9 20RD/LB (PREMIUM II/III) SEAT SWITCH B(+) SUPPLY
15 Z6 16BK/YL (PREMIUM I/III) GROUND
16 Z5 16BK/VT (PREMIUM I/III) GROUND
17 - -
18 P141 16GY/WT (PREMIUM II/III) SEAT RECLINER DOWN DRIVER
19 P143 16GY/LB (PREMIUM II/III) SEAT RECLINER UP DRIVER
20 P117 16RD/BR (PREMIUM II/III) SEAT HORIZONTAL REARWARD DRIVER
SENTRY KEY IMMOBILIZER MODULE - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1 M1 20PK FUSED B(+)
2 Z132 20BK/OR GROUND
3 G5 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
4- -
5 D25 20YL/VT/BK PCI BUS
6- -
SHIFTER ASSEMBLY (C201 DIESEL) - WHITE 12 WAY
CAV CIRCUIT FUNCTION
1- -
2- -
3- -
4 K2 20WT/PK SECONDARY BRAKE SWITCH SIGNAL
5 D25 20RD PCI BUS
6- -
7 D21 20PK SCI TRANSMIT
8 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
9 T2 20TN/BK BACK-UP LAMP RELAY CONTROL
10 Z234 20WT GROUND
11 T41 20BK/WT PARK/NEUTRAL POSITION SWITCH SENSE (T41)
12 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 119

SHIFTER ASSEMBLY (GAS) - WHITE 6 WAY
CAV CIRCUIT FUNCTION
1 E2 20OR PANEL LAMPS DRIVER
2 Z234 18BK GROUND
3 T6 18OR/WT OVERDRIVE OFF SWITCH SENSE
4 Z300 18BK GROUND
5 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
6 K29 18WT/PK SECONDARY BRAKE SWITCH SIGNAL
SHIFTER ASSEMBLY C1 (DIESEL) - BLACK 12 WAY
CAV CIRCUIT FUNCTION
1 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
2 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
3 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
4 T2 20TN/BK BACK-UP LAMP RELAY CONTROL
5 D25 20OR PCI BUS
6 W0 20DB/WT SHIFTER C1 SENSE
7 W1 20VT/WT SHIFTER C2 SENSE
8 W2 20VT SHIFTER C3 SENSE
9 W3 20BK SHIFTER C4 SENSE
10 W4 20PK/OR SHIFTER C5 SENSE
11 Z234 20WT GROUND
12 Z234 20WT GROUND
SHIFTER ASSEMBLY C2 (DIESEL)-6WAY
CAV CIRCUIT FUNCTION
1- -
2- -
3 F12 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
4 K2 20WT/PK SECONDARY BRAKE SWITCH SIGNAL
5 F991 20OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
6 Y1 20DB/PK PARK LOCKOUT SOLENOID CONTROL
SIREN (BUILT-UP-EXPORT)-3WAY
CAV CIRCUIT FUNCTION
1 Z141 18BK GROUND
2 X75 18GY/LB (DIESEL) SIREN SIGNAL CONTROL
2 X75 18GY/LG (GAS) SIREN SIGNAL CONTROL
3 M1 18PK FUSED B(+)
SPEED CONTROL SWITCH NO. 1 - BLACK 4 WAY
CAV CIRCUIT FUNCTION
1- -
2 K4 20BK/LB SENSOR GROUND
3 V37 20RD/LG SPEED CONTROL SWITCH SIGNAL
4- -
8W - 80 - 120 8W-80 CONNECTOR PIN-OUTWJ

TRANSMISSION CONTROL MODULE (4.7L) - BLACK 60 WAY
CAV CIRCUIT FUNCTION
1 T1 18LG/BK TRS T1 SENSE
2 T2 18TN/BK TRS T2 SENSE
3 T3 18VT TRS T3 SENSE
4- -
5- -
6 K24 18GY/BK CRANKSHAFT POSITION SENSOR SIGNAL
7 D21 18PK SCI TRANSMIT
8 F45 18YL/RD FUSED IGNITION SWITCH OUTPUT (START)
9 T9 18OR/BK OVERDRIVE PRESSURE SWITCH SENSE
10 T10 18YL/DG TORQUE MANAGEMENT REQUEST SENSE
11 F991 18OR/DB FUSED IGNITION SWITCH OUTPUT (RUN-START)
12 K22 18OR/RD THROTTLE POSITION SENSOR SIGNAL
13 T13 18DB/BK SPEED SENSOR GROUND
14 T14 18LG/WT OUTPUT SPEED SENSOR SIGNAL
15 K30 18PK/YL TRANSMISSION CONTROL RELAY CONTROL
16 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
17 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
18 T118 18YL/DB PRESSURE CONTROL SOLENOID CONTROL
19 T119 18WT/DB 2C SOLENOID CONTROL
20 T120 18LG LR SOLENOID CONTROL
21 - -
22 - -
23 - -
24 - -
25 - -
26 - -
27 - -
28 - -
29 T29 18GY UNDERDRIVE PRESSURE SWITCH SENSE
30 T130 14VT/TN LINE PRESSURE SENSOR SIGNAL
31 - -
32 - -
33 - -
34 - -
35 - -
36 T16 14RD TRANSMISSION CONTROL RELAY OUTPUT
37 Z113 14BK/WT GROUND
38 T138 14GY/LB 5 VOLT SUPPLY
39 Z112 14BK/YL GROUND
40 T140 18VT/LG MS SOLENOID CONTROL
41 T41 18WT TRS T41 SENSE
42 T42 18VT/WT TRS T42 SENSE
43 D25 18YL/VT PCI BUS
44 - -
45 - -
46 D20 18LG SCI RECEIVE
47 T147 18LB 2C PRESSURE SWITCH SENSE
48 T48 18DB 4C PRESSURE SWITCH SENSE
49 T6 18VT/WT OVERDRIVE OFF SWITCH SENSE
50 T150 18BR/LB LR PRESSURE SWITCH SENSE
51 K4 18BK/LB SENSOR GROUND
52 T52 18RD/BK INPUT SPEED SENSOR SIGNAL
53 Z114 14BK/LG GROUND
54 T54 18VT TRANSMISSION TEMPERATURE SENSOR SIGNAL
55 T59 18PK UNDERDRIVE SOLENOID CONTROL
56 A30 14RD/WT FUSED B(+)
57 Z12 14BK/TN GROUND
58 - -
59 T159 18DG/WT 4C SOLENOID CONTROL
60 T60 18BR OVERDRIVE SOLENOID CONTROL
8W - 80 - 124 8W-80 CONNECTOR PIN-OUTWJ

VEHICLE INFORMATION CENTER - BLACK 6 WAY
CAV CIRCUIT FUNCTION
1- -
2 D25 20YL/VT PCI BUS
3 F70 20PK FUSED B(+)
4 Z155 20BK/OR GROUND
5 G5 20DB/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
6- -
VISCOUS/CABIN HEATER (DIESEL) - BLACK 2 WAY
CAV CIRCUIT FUNCTION
1 A82 16PK/LG VISCOUS/CABIN HEATER RELAY OUTPUT
2 Z18 16BK GROUND
WASHER FLUID LEVEL SWITCH - GRAY 2 WAY
CAV CIRCUIT FUNCTION
1 V11 20BK/TN WASHER FLUID SWITCH SENSE
2 Z141 20BK GROUND
WASTEGATE SOLENOID (DIESEL)-2WAY
CAV CIRCUIT FUNCTION
1 F15 18DB/WT FUSED AUTO SHUT DOWN RELAY OUTPUT
2 Y42 18OR/DB WASTEGATE SOLENOID CONTROL
WATER IN FUEL SENSOR (DIESEL) - BLACK 3 WAY
CAV CIRCUIT FUNCTION
1 K4 20BK/LB SENSOR GROUND
2 G123 20DG/WT WATER IN FUEL SENSOR SIGNAL
3 F15 20RD/DG FUSED AUTO SHUT DOWN RELAY OUTPUT
WJ8W-80 CONNECTOR PIN-OUT 8W - 80 - 127

(9) Lower the engine until it is properly located on
the engine mounts.
(10) Install the through bolts and tighten the nuts.
(11) Lower the jack stand and remove the piece of
wood.
(12) Install the engine flywheel and transmission
torque converter housing access cover.
(13) Install the engine starter motor. (Refer to 8 -
ELECTRICAL/STARTING/STARTER MOTOR -
INSTALLATION).
(14) Connect the exhaust pipe to the hanger and to
the engine exhaust manifold.
(15) Install transmission oil cooling lines (if
equipped) and oxygen sensor wiring supports that
attach to the oil pan studs.
(16) Install the oil pan drain plug (Fig. 81).
Tighten the plug to 34 N´m (25 ft. lbs.) torque.
(17) Lower the vehicle.
(18) Connect negative cable to battery.
(19) Fill the oil pan with engine oil to the specified
level.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS OR FAN. DO
NOT WEAR LOOSE CLOTHING.
(20) Start the engine and inspect for leaks.
ENGINE OIL PRESSURE
SENSOR
DESCRIPTION
The 3±wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.
OPERATION
The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²A signal to the PCM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to theinstrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
OIL PUMP
REMOVAL
A gear-type oil pump is mounted at the underside
of the cylinder block opposite the No.4 main bearing.
(1) Drain the engine oil.
(2) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(3) Remove the pump-to-cylinder block attaching
bolts. Remove the pump assembly with gasket (Fig.
82).
CAUTION: If the oil pump is not to be serviced, DO
NOT disturb position of oil inlet tube and strainer
assembly in pump body. If the tube is moved within
the pump body, a replacement tube and strainer
assembly must be installed to assure an airtight
seal.
Fig. 82 Oil Pump Assembly
1 - OIL FILTER ADAPTOR
2 - BLOCK
3 - GASKET
4 - OIL INLET TUBE
5 - OIL PUMP
6 - STRAINER ASSEMBLY
7 - ATTACHING BOLTS
9 - 56 ENGINE - 4.0LWJ
OIL PAN (Continued)

NOTE: When installing oil pan gasket/windage tray,
start four pan bolts at each corner before tightening
oil pickup tube. This will keep pan gasket in align-
ment.
(3) Install oil pump pick-up tube using a new
O-ring. First tighten bolt at O-ring end of tube to 28
N´m (20 ft. lbs.). Tighten remain tube support fasten-
ers to 28 N´m (20 ft. lbs.).
(4) Install oil pan and tighten fasteners to 15 N´m
(11 ft. lbs.) (Fig. 95).
(5) Reconnect transmission oil cooler lines to oil
pan stud bolt.
(6) Install starter (Refer to 8 - ELECTRICAL/
STARTING/STARTER MOTOR - INSTALLATION).
(7) Install exhaust system Y-pipe.
(8) Install structural cover (Refer to 9 - ENGINE/
ENGINE BLOCK/STRUCTURAL COVER - INSTAL-
LATION).
(9) Lower vehicle.
(10) Fill engine with proper amount of oil (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
SPECIFICATIONS).
(11) Connect negative cable to battery.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, solid-state engine oil pressure sensor
(sending unit) is located in an engine oil pressure
gallery.
OPERATION
The oil pressure sensor uses three circuits. They are:
²A 5±volt power supply from the Powertrain Con-
trol Module (PCM)
²A sensor ground through the PCM's sensor
return
²
A signal to the PCM relating to engine oil pressure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor. Meaning different pressures
relate to different output voltages.
A 5±volt supply is sent to the sensor from the PCM
to power up the sensor. The sensor returns a voltage
signal back to the PCM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on either a CCD or PCI bus circuit
(depending on vehicle line) to operate the oil pressure
gauge and the check gauges lamp. Ground for the
sensor is provided by the PCM through a low-noise
sensor return.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise vehicle on hoist.
(3) Remove front splash shield.
(4) Disconnect oil pressure sender wire (Fig. 96).
(5) Remove the pressure sender (Fig. 96).
INSTALLATION
(1) Install oil pressure sender.
(2) Connect oil pressure sender wire.
(3) Install front splash shield.
(4) Lower vehicle.
(5) Connect the negative battery cable.
Fig. 95 Oil Pan Tightening Sequence
Fig. 96 Oil Pressure Sending Unit
1 - BELT
2 - OIL PRESSURE SENSOR
3 - OIL FILTER
4 - ELEC. CONNECTOR
WJENGINE - 4.7L 9 - 133
OIL PAN (Continued)

KEY-IN IGNITION SWITCH
DESCRIPTION
The key-in ignition switch is concealed within and
integral to the ignition switch, which is mounted on
the steering column. The key-in ignition switch is
actuated by the ignition lock cylinder mechanism,
and is hard wired between a body ground and the
Body Control Module (BCM) through the instrument
panel wire harness.
The key-in ignition switch cannot be adjusted or
repaired and, if faulty or damaged, the entire igni-
tion switch unit must be replaced,(Refer to 19 -
STEERING/COLUMN/LOCK CYLINDER HOUSING
- REMOVAL). For complete circuit diagrams, refer to
Body Control Modulein the Contents of Wiring
Diagrams.
OPERATION
The key-in ignition switch closes a path to ground
for the BCM when the ignition key is inserted in the
ignition lock cylinder, and opens the ground path
when the key is removed from the ignition lock cyl-
inder. The BCM monitors the key-in ignition switch
status through an internal pull-up, then sends the
proper switch status messages to other electronic
modules over the Programmable Communications
Interface (PCI) data bus network. The key-in ignition
switch status is also used by the BCM as an input
for chime warning system operation.
DIAGNOSIS AND TESTING
KEY-IN IGNITION SWITCH
For complete circuit diagrams, refer toBody Con-
trol Modulein the Contents of Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO GROUP 8M - PASSIVE
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. 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. Disconnect the instrument panel wire harness
connector from the key-in ignition switch connector
receptacle on the ignition switch. Check for continu-
ity between the key-in ignition switch sense and
ground terminals of the key-in ignition switch con-
nector receptacle. There should be continuity with
the key inserted in the ignition lock cylinder, and no
continuity with the key removed from the ignition
lock cylinder. If OK, go to Step 2. If not OK, replace
the faulty ignition switch unit.
(2) Check for continuity between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector for the key-in ignition switch and a good
ground. There should be continuity. If OK, go to Step
3. If not OK, repair the open ground circuit to ground
as required.
(3) Disconnect the gray 26-way instrument panel
wire harness connector from the Body Control Mod-
ule (BCM) connector receptacle. Check for continuity
between the key-in ignition switch sense circuit cav-
ity of the instrument panel wire harness connector
for the key-in ignition switch and a good ground.
There should be no continuity. If OK, go to Step 4. If
not OK, repair the shorted key-in ignition switch
sense circuit as required.
(4) Check for continuity between the key-in igni-
tion switch sense circuit cavities of the instrument
panel wire harness connector for the key-in ignition
switch and the gray 26-way instrument panel wire
harness connector for the BCM. There should be con-
tinuity. If OK, use a DRB scan tool and the proper
Diagnostic Procedures manual to test the BCM. If
not OK, repair the open key-in ignition switch sense
circuit as required.
LOCK CYLINDER
REMOVAL
The ignition key must be in the key cylinder for
cylinder removal. The key cylinder must be removed
first before removing ignition switch.
(1) Disconnect negative battery cable at battery.
(2) If equipped with an automatic transmission,
place shifter in PARK position.
(3) Rotate key to ON position.
19 - 14 COLUMNWJ

Both the manual A/C Heater control panel and the
AZC control panel are serviced only as complete
units and cannot be repaired. If faulty or damaged,
the entire control panel unit must be replaced.
DIAGNOSIS AND TESTING - AUTOMATIC ZONE
CONTROL SYSTEM
The Automatic Zone Control (AZC) control module
has a system self-diagnostic mode which continuously
monitors various parameters during normal system
operation. If a system fault is detected, a current and
historical fault is recorded. When the current fault is
cleared, the historical fault remains until reset (man-
ually or automatically). Both the current and histor-
ical fault codes can be accessed through either the
front panel, or over the Programmable Communica-
tions Interface (PCI) bus using a DRBIIItscan tool,
and the appropriate diagnostic information.
The AZC control module is capable of three differ-
ent types of self-diagnostic tests, as follows:
²Fault Code Tests
²Input Circuit Tests
²Output Circuit/Actuator Tests
The information that follows describes:
²How to read the self-diagnostic display
²How to enter the AZC control module self-diag-
nostic test mode
²How to select the self-diagnostic test types
²How to perform the different tests
ENTERING THE AZC SELF-DIAGNOSTIC MODE
To enter the AZC self-diagnostic mode, perform the
following:
(1) Depress the a/c and recirc buttons at the same
time and hold. Rotate the left temperature control
knob clockwise (CW) one detent.
(2) If you continue to keep the a/c and recirc but-
tons depressed, the AZC control module will perform
a Segment Test of the Vacuum Fluorescent (VF) dis-
play. In the Segment Test you should see all of the
display segments illuminate as long as both buttons
are held. If a display segment fails to illuminate, the
vacuum fluorescent display is faulty and the a/c
heater control must be replaced.
(3) After viewing the Segment Test, release the
A/C and Recirc buttons and the display will clear
momentarily.Ifa0isdisplayed, then no faults
are set in the system.Should there be any faults,
either9current9or9historical9, all fault codes will be
displayed in ascending numerical sequence (note no
effort is made to display fault codes in chronological
order). Each fault code is displayed for one second
before the next code is displayed. Once all fault codes
have been displayed, the system will then repeat the
fault code numbers. This will continue until the left
side set temperature control is moved at least onedetent position in the CW direction or the ignition is
turned9OFF9.
FAULT CODE TESTS
Fault codes are two-digit numbers that identify a
circuit that is malfunctioning. There are two differ-
ent kinds of fault codes.
1.Current Fault Codes- Current means the
fault is present right now. There are two types of cur-
rent faults: input faults, and system faults.
2.Historical Fault Codes- Historical or stored
means that the fault occurred previously, but is not
present right now. A majority of historical fault codes
are caused by intermittent wire harness or wire har-
ness connector problems.
CURRENT FAULT CODES
Input faults 01 = IR thermister circuit
open
02 = IR thermister circuit
shorted
03 = Fan pot shorted
04 = Fan pot open
05 = Mode pot shorted
06 = Mode pot open
07 = IR sensor delta too
large
08 = Reserved
09 = Reserved
10 = One of four motor
drivers has drive9A9
shorted to ground
11 = Engine air intake
temperature Buss
message missing
12 = Country code Buss
message missing
24 - 18 CONTROLSWJ
A/C HEATER CONTROL (Continued)