TABLE OF CONTENTS
1.0 INTRODUCTION.........................................................1
1.1SYSTEM COVERAGE...............................................1
1.2SIX-STEP TROUBLESHOOTING PROCEDURE..........................1
2.0 IDENTIFICATION OF SYSTEM.............................................1
3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION......................1
3.1AIRBAG SYSTEM/OCCUPANT RESTRAINT CONTROLLER SYSTEM........2
3.1.1DRIVER AIRBAG...........................................3
3.1.2CLOCKSPRING............................................4
3.1.3PASSENGER AIRBAG......................................4
3.1.4SEAT BELT TENSIONER (SBT)...............................5
3.1.5SEAT BELT SWITCHES (SBS)................................5
3.1.6SIDE IMPACT AIRBAG CONTROL MODULE (SIACM)............5
3.1.7SEAT AIRBAGS (SAB)......................................6
3.1.8ORC/SIACM DIAGNOSTIC TROUBLE CODES..................6
3.1.9ACTIVE CODES...........................................7
3.1.10STORED CODES..........................................7
3.2AUDIO SYSTEM....................................................7
3.2.1REMOTE RADIO CONTROLS................................8
3.2.2CD CHANGER.............................................8
3.3BODY CONTROL MODULE...........................................8
3.4CHIME WARNING SYSTEM...........................................9
3.4.1CHIME PRIORITY..........................................9
3.4.2CHIME ON CONDITIONS....................................9
3.4.3WARNING LAMP ANNOUNCEMENT.........................10
3.4.4OTHER CHIME ON CONDITIONS............................10
3.5COMMUNICATION.................................................11
3.6DOOR AJAR SYSTEM..............................................12
3.7EXTERIOR LIGHTING SYSTEM......................................12
3.7.1HEADLAMP POWER......................................12
3.7.2HEADLAMP SWITCH......................................12
3.7.3PARK LAMP RELAY.......................................12
3.7.4FOG LAMP RELAY........................................12
3.7.5FOG LAMPS.............................................12
3.7.6EXTERIOR LIGHTING BATTERY SAVER......................13
3.7.7AUTO HEADLAMPS.......................................13
3.8FRONT CONTROL MODULE.........................................13
3.8.1CONTROLLED POWER FEEDS.............................13
3.8.2RELAY CONTROLS.......................................14
3.8.3ELECTRICAL INPUTS.....................................15
3.9HEATING & A/C...................................................16
3.9.1AUTOMATIC TEMPERATURE CONTROL (ATC)................16
3.9.1.1CABIN HEATER..........................................16
3.9.1.2SYSTEM OPERATION.....................................16
3.9.1.3BLOWER MOTOR OPERATION.............................16
3.9.1.4INFRARED SENSORS.....................................16
3.9.1.5REAR ATC SWITCH.......................................16
3.9.1.6COOLDOWN TESTING....................................16
3.9.1.7ACTIVE AND STORED TROUBLE CODES....................17
3.9.2MANUAL TEMPERATURE CONTROL.........................17
i
TABLE OF CONTENTS - Continued
HIGH BEAM SWITCH INPUT SHORT......................................456
LEFT FRONT TURN SIGNAL OUTPUT OPEN...............................458
LEFT FRONT TURN SIGNAL OUTPUT SHORT..............................460
LEFT HIGH BEAM HEADLAMP CIRCUIT OPEN.............................462
LEFT HIGH BEAM HEADLAMP CIRCUIT SHORTED TO GROUND.............464
LEFT HIGH BEAM HEADLAMP CIRCUIT SHORTED TO VOLTAGE.............466
LEFT LOW BEAM HEADLAMP CIRCUIT OPEN.............................468
LEFT LOW BEAM HEADLAMP CIRCUIT SHORTED TO GROUND..............470
LEFT LOW BEAM HEADLAMP CIRCUIT SHORTED TO VOLTAGE..............472
LEFT REAR TURN SIGNAL OUTPUT OPEN................................474
LEFT REAR TURN SIGNAL OUTPUT SHORT...............................476
LEFT SIDE PARK LAMP OPEN...........................................478
PARK LAMP OUTPUT 1 OPEN...........................................480
PARK LAMP OUTPUT 1 SHORT TO BATTERY..............................482
PARK LAMP OUTPUT 2 OPEN...........................................483
PARK LAMP OUTPUT 2 SHORT TO BATTERY..............................485
RIGHT FRONT TURN SIGNAL OUTPUT OPEN..............................486
RIGHT FRONT TURN SIGNAL OUTPUT SHORT............................488
RIGHT HIGH BEAM HEADLAMP CIRCUIT OPEN............................490
RIGHT HIGH BEAM HEADLAMP CIRCUIT SHORTED TO GROUND............492
RIGHT HIGH BEAM HEADLAMP CIRCUIT SHORTED TO VOLTAGE............494
RIGHT LOW BEAM HEADLAMP CIRCUIT OPEN............................496
RIGHT LOW BEAM HEADLAMP CIRCUIT SHORTED TO GROUND.............498
RIGHT LOW BEAM HEADLAMP CIRCUIT SHORTED TO VOLTAGE............500
RIGHT REAR TURN SIGNAL OUTPUT OPEN...............................502
RIGHT REAR TURN SIGNAL OUTPUT SHORT..............................504
RIGHT SIDE PARK LAMP OPEN..........................................506
TURN SIGNAL SWITCH INPUT OPEN.....................................508
TURN SIGNAL SWITCH INPUT SHORT....................................510
HEATING & A/C
A/C FAULT (ACTIVE) - MANUAL A/C......................................512
CHECKSUM FAILURE (ACTIVE) - MANUAL A/C.............................512
POWER FAULT (ACTIVE) - MANUAL A/C..................................512
REAR DEFOG FAILURE (ACTIVE) - MAN A/C...............................512
RECIRCULATION FAULT (ACTIVE) - MANUAL A/C...........................512
UNKNOWN FAULT DETECTED (ACTIVE) - MANUAL A/C.....................512
A/C FAULT (STORED) - MANUAL A/C.....................................514
BACKLIGHT DIMMING RX FAILURE (STORED) - MANUAL A/C................514
BLEND OVERCURRENT (STORED) - MANUAL A/C..........................514
CHECKSUM FAILURE (STORED) - MANUAL A/C............................514
EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN (STORED) - MANUAL
A/C..................................................................514
EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORT (STORED) - MANUAL
A/C..................................................................514
LOOPBACK FAILURE (STORED) - MANUAL A/C............................514
LOOPBACK TEST FAILURE (STORED) - MANUAL A/C.......................514
MODE OVERCURRENT (STORED) - MANUAL A/C..........................514
NO BCM MESSAGE RECEIVED (STORED) - MANUAL A/C...................514
NO PCM MESSAGE RECEIVED (STORED) - MANUAL A/C...................514
PCM COMMUNICATION FAILURE (STORED) - MANUAL A/C..................514
POWER FAULT (STORED) - MANUAL A/C.................................514
REAR BLEND OVERCURRENT (STORED) - MANUAL A/C....................514
xii
TABLE OF CONTENTS - Continued
REAR BLEND POT CIRCUIT OPEN (STORED) - MANUAL A/C.................514
REAR BLEND POT CIRCUIT SHORT (STORED) - MANUAL A/C...............514
REAR DEFOG FAILURE (STORED) - MANUAL A/C..........................514
REAR MODE OVERCURRENT (STORED) - MANUAL A/C.....................514
RECIRC OVERCURRENT (STORED) - MANUAL A/C.........................514
RECIRCULATION FAULT (STORED) - MANUAL A/C..........................514
TX FAILURE (STORED) - MANUAL A/C....................................514
UNKNOWN FAULT DETECTED (STORED) - MANUAL A/C....................514
VEHICLE ODOMETER FAILURE (STORED) - MANUAL A/C...................514
ZONE OVERCURRENT (STORED) - MANUAL A/C...........................514
BACKLIGHT DIMMING RX FAILURE (ACTIVE) - MANUAL A/C.................519
NO BCM MESSAGE RECEIVED (ACTIVE) - MANUAL A/C....................519
BLEND CALIBRATION FAULT - MANUAL A/C...............................521
MODE CALIBRATION FAULT - MANUAL A/C................................521
RECIRCULATION CALIBRATION FAULT - MANUAL A/C......................521
ZONE CALIBRATION FAULT - MANUAL A/C................................521
BLEND OVERCURRENT (ACTIVE) - MANUAL A/C...........................526
MODE OVERCURRENT (ACTIVE) - MANUAL A/C...........................526
REAR BLEND OVERCURRENT (ACTIVE) - MANUAL A/C.....................526
REAR MODE OVERCURRENT (ACTIVE) - MANUAL A/C......................526
RECIRC OVERCURRENT (ACTIVE) - MANUAL A/C..........................526
ZONE OVERCURRENT (ACTIVE) - MANUAL A/C............................526
COOLDOWN TEST EXCESSIVE FAULT - MANUAL A/C.......................532
COOLDOWN TEST SENSOR FAILURE - MANUAL A/C.......................532
COOLDOWN TEST SET UP FAULT - MANUAL A/C..........................534
COOLDOWN TEST TOO COLD TO START - MANUAL A/C....................535
EVAPORATOR TEMPERATURE SENSOR CIRCUIT OPEN (ACTIVE) - MANUAL
A/C..................................................................538
EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORT (ACTIVE) - MANUAL
A/C..................................................................540
FRONT AND REAR BLOWER OUTPUT 1 OPEN............................542
FRONT AND REAR BLOWER OUTPUT 2 OPEN............................542
FRONT AND REAR BLOWER OUTPUT 1 SHORT TO BATT...................544
FRONT AND REAR BLOWER OUTPUT 2 SHORT TO BATT...................544
LOOPBACK FAILURE (ACTIVE) - MANUAL A/C.............................546
LOOPBACK TEST FAILURE (ACTIVE) - MANUAL A/C........................546
NO PCM MESSAGE RECEIVED (ACTIVE) - MANUAL A/C....................547
PCM COMMUNICATION FAILURE (ACTIVE) - MANUAL A/C...................547
VEHICLE ODOMETER FAILURE (ACTIVE) - MANUAL A/C....................547
REAR BLEND CALIBRATION FAULT - MANUAL A/C.........................549
REAR MODE CALIBRATION FAULT - MANUAL A/C..........................549
REAR BLEND POT CIRCUIT OPEN (ACTIVE) - MANUAL A/C..................553
REAR BLEND POT CIRCUIT SHORT (ACTIVE) - MANUAL A/C................556
TX FAILURE (ACTIVE) - MANUAL A/C.....................................559
INSTRUMENT CLUSTER
ABS LAMP CKT SHORT................................................561
ABS LAMP OPEN......................................................562
AIRBAG LAMP CKT SHORT.............................................563
AIRBAG LAMP OPEN...................................................564
EL PANEL SHORT.....................................................565
FRONT FOG LAMP INDICATOR OPEN....................................567
FRONT FOG LAMP INDICATOR SHORT TO GROUND.......................569
xiii
TABLE OF CONTENTS - Continued
FUEL GAUGE CHECKSUM FAILURE......................................571
FUEL LEVEL SENDING UNIT INPUT OPEN................................572
FUEL LEVEL SENDING UNIT INPUT SHORT...............................574
IOD WAKEUP CLUSTER OUTPUT OPEN..................................576
IOD WAKEUP CLUSTER OUTPUT SHORT.................................578
LEFT TURN SIGNAL INDICATOR OPEN (HIGHLINE).........................580
LEFT TURN SIGNAL INDICATOR OPEN (LOWLINE).........................582
LEFT TURN SIGNAL INDICATOR SHORT (HIGHLINE)........................584
LEFT TURN SIGNAL INDICATOR SHORT (LOWLINE)........................586
LOOPBACK FAILURE...................................................588
NO ABS BUS MESSAGES RECEIVED.....................................589
NO BCM BUS MESSAGES RECEIVED....................................590
NO FCM BUS MESSAGES RECEIVED....................................591
NO ORC BUS MESSAGES RECEIVED....................................592
NO PCM BUS MESSAGES RECEIVED....................................593
NO TCM BUS MESSAGES RECEIVED....................................594
PANEL DIMMING OUTPUT SHORT.......................................595
REAR FOG INDICATOR OUTPUT OPEN...................................600
REAR FOG INDICATOR OUTPUT SHORT..................................602
RIGHT TURN SIGNAL INDICATOR OPEN (HIGHLINE)........................604
RIGHT TURN SIGNAL INDICATOR OPEN (LOWLINE)........................606
RIGHT TURN SIGNAL INDICATOR SHORT (HIGHLINE)......................608
RIGHT TURN SIGNAL INDICATOR SHORT (LOWLINE).......................610
SPEEDOMETER CHECKSUM FAILURE....................................612
TACHOMETER CHECKSUM FAILURE.....................................613
TCM MESSAGE MISMATCH.............................................614
TEMPERATURE GAUGE CHECKSUM FAILURE.............................615
*ANY PCI BUS INDICATOR INOPERATIVE.................................616
INTELLIGENT POWER MODULE
ACCESSORY POWER OUTPUT #1 OPEN.................................617
ACCESSORY POWER OUTPUT #1 SHORTED TO BATTERY..................619
ACCESSORY POWER OUTPUT #2 OPEN.................................621
ACCESSORY POWER OUTPUT #2 SHORTED TO BATTERY..................623
CPA NOT ENGAGED...................................................625
IGN RUN/START INPUT WIRING.........................................627
IGNITION START INPUT WIRING.........................................629
INTERNAL DRIVER FAULT #1............................................631
INTERNAL DRIVER FAULT #2............................................632
INTERNAL DRIVER FAULT #3............................................633
INTERIOR LIGHTING
DOME LAMP OUTPUT SHORT...........................................634
DOME SWITCH INPUT OPEN............................................635
DOME SWITCH INPUT SHORT...........................................636
FRONT COURTESY LAMPS OUTPUT SHORT..............................638
HALO/DOOR/LIFTGATE LAMP OUTPUT SHORT............................640
READING LAMP OUTPUT SHORT........................................641
MEMORY SEAT
BCM MESSAGE NOT RECEIVED.........................................642
CHARGING VOLTAGE HIGH MESSAGE...................................643
CHARGING VOLTAGE LOW MESSAGE....................................644
xiv
TABLE OF CONTENTS - Continued
RIGHT SLIDING DOOR CONTROL MODULE C1 (POWER SLIDING DOOR) - BLACK
8 WAY ..............................................................1082
RIGHT SLIDING DOOR CONTROL MODULE C2 (POWER SLIDING DOOR) -
BLACK/RED 20 WAY..................................................1082
RIGHT SLIDING DOOR LATCH SENSING SWITCH (POWER SLIDING DOOR) -
BLACK 6 WAY........................................................1082
RIGHT SLIDING DOOR LOCK MOTOR (POWER SLIDING DOOR) - BLACK 4
WAY................................................................1083
RIGHT SLIDING DOOR LOCK MOTOR/AJAR SWITCH (MANUAL SLIDING DOOR) -
BLACK 4 WAY........................................................1083
RIGHT SLIDING DOOR MOTOR (POWER SLIDING DOOR) - BLACK 8 WAY. . . .1083
SENTRY KEY IMMOBILIZER MODULE - BLACK 6 WAY.....................1083
SIREN (UNITED KINGDOM) - BLACK 4 WAY..............................1083
THATCHAM ALARM MODULE C1 (UNITED KINGDOM) - BLACK 16 WAY.......1084
THATCHAM ALARM MODULE C2 (UNITED KINGDOM) - WHITE 4 WAY........1084
TRANSMISSION CONTROL MODULE (EATX) - BLACK 60 WAY..............1085
TXV SOLENOID (ATC)-2WAY.........................................1086
10.0 SCHEMATIC DIAGRAMS...............................................1087
10.1AIRBAG SYSTEM................................................1087
10.2AUDIO SYSTEM.................................................1088
10.2.1PREMIUM.............................................1088
10.2.2BASE.................................................1089
10.2.3CD CHANGER.........................................1090
10.2.4REMOTE RADIO CONTROLS.............................1091
10.3CABIN HEATER.................................................1092
10.4AUTOMATIC TEMPERATURE CONTROL SYSTEM....................1093
10.4.1FRONT ATC............................................1093
10.4.2REAR ATC.............................................1094
10.5COMMUNICATION...............................................1095
10.5.1PCM COMMUNICATION.................................1096
10.5.2ECM & CABIN HEATER ASSIST COMMUNICATION - DIESEL
ONLY.................................................1096
10.6DOOR AJAR WITH POWER SLIDING DOORS........................1097
10.7DOOR AJAR WITHOUT POWER SLIDING DOORS....................1098
10.8EXTERIOR LIGHTING............................................1099
10.9IGNITION SWITCH...............................................1100
10.10INSTRUMENT CLUSTER Ð BASE..................................1101
10.11INSTRUMENT CLUSTER & MESSAGE CENTER......................1102
10.12INTELLIGENT POWER MODULE/BODY CONTROL MODULE POWER AND
GROUNDS......................................................1103
10.13INTERIOR LIGHTING.............................................1104
10.14MANUAL TEMPERATURE CONTROLS..............................1105
10.14.1BASE MANUAL TEMPERATURE CONTROL SYSTEM LHD.....1105
10.14.2BASE MANUAL TEMPERATURE CONTROL SYSTEM RHD....1106
10.14.3DUAL-ZONE MANUAL TEMPERATURE CONTROL SYSTEM
LHD ..................................................1107
10.14.4DUAL-ZONE MANUAL TEMPERATURE CONTROL SYSTEM
RHD..................................................1108
10.14.5BLOWER MOTOR.......................................1109
10.15MEMORY SYSTEM...............................................1110
10.16OVERHEAD CONSOLE...........................................1111
xxiv
3.7.6 EXTERIOR LIGHTING BATTERY
SAVER
The BCM monitors the status of, and controls, the
Park Lamps, Headlamps and Fog Lamp relays. If
any exterior lamps are left ON after the ignition is
turned OFF, the BCM will turn them OFF after 3
minutes.
3.7.7 AUTO HEADLAMPS
This feature is available on vehicles equipped
with both the Electrocromatic Mirror (ECM) and
the Compass/Mini-Trip Computer (CMTC). When
the BCM detects a day/night signal from the CMTC,
an ECM is present and Auto Headlamp mode is
selected.
3.8 FRONT CONTROL MODULE
The Front Control Module (FCM) is an electrical
control and interface center located in the engine
compartment. When it is mated to the Power Dis-
tribution Center (PDC), it is referred to as the
Intelligent Power Module (IPM). The IPM, with its
fuses and relays provides power and signal distri-
bution throughout most of the vehicle. The FCM
receives both hard wire and digital electronic inputs
from the vehicle electrical system through the PDC.
Based on these inputs and the ignition switch
position, it provides direct power feeds and relay
control to some of the vehicles' most critical electri-
cal systems.
The Front Control Module provides the following
features:
Controlled power feeds:
²Front airbag system
²Side airbag system
²Headlamp power
²EATX module power (4 speed only)
²Front washer motor
²Rear washer motor
²Brake shift interlock system
Relay controls:
²Fog lamp relay (when equipped)
²Park lamp relay
²Front wiper on relay
²Front wiper high/low relay
²Accessory relay
²Horn relay
²Front & rear blower relay
²Name brand speakers (NBS) relay
²Electronic back light (EBL) run only relay
²Cabin heater relayElectrical inputs:
²Headlamp battery supplies1&2
²Module battery supply
²Power ground
²Ignition switch RUN or START position status
²Ignition switch START only status
²PCI Bus
²Stop lamp switch
²Horn switch
²Back-up switch
²Wiper park switch
²Washer fluid level switch
²Brake fluid level switch
²Ambient temperature sensor
²Right park lamp outage
²Left park lamp outage
²Battery IOD
²Battery (+) connection detection
²Flash reprogramming voltage
3.8.1 CONTROLLED POWER FEEDS
Front airbag system
The FCM provides power to the Occupant Re-
straint Control (ORC) system through two ªfuse-
lessº circuits (ORC RUN/START, and ORC RUN
only). These circuits are electronically controlled
and continuously monitored for malfunctions.
Power is supplied while the ignition switch is in the
RUN and START positions on pin 48 of the FCM
connector, and in the RUN only position on pin 29.
Side airbag system
The FCM provides power to the Side Impact
Airbag Control Module (SIACM) system through
one ªfuselessº circuit. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. Power is supplied in the ignition RUN and
START positions on pin 28 of the FCM connector.
Headlamp power
The headlamp switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it of a headlamp switch status
change. The FCM then turns on power to the
headlamps through four ªfuselessº circuits. These
circuits are electronically controlled and continu-
ously monitored for malfunctions. Power is supplied
to each filament in a separate circuit (RH low on pin
6, RH high on pin 4, LH low on pin 3 and LH high
on pin 5). For vehicles equipped with Daytime
Running Lamps (DRL), the FCM electronically
steps down the headlamp voltage to provide the
desired illumination.
13
GENERAL INFORMATION
Front and rear blower relay
The blower control switch is part of the Automatic
Temperature Control (ATC) or A/C-Heater Control
Module, (Manual Temp). When the blower switch is
turned on, the ATC or A/C-Heater Control Module
sends a PCI Bus message to the FCM. The front and
rear blower relay is then powered through low side
control on pin 30 of the FCM. The relay provides the
high side to the blower motor, and the blower speed
is governed through low side control in the ATC or
A/C-Heater Control Module. This circuit is electron-
ically controlled and continuously monitored for
malfunctions.
Name Brand Speakers (NBS) relay
The NBS relay operates through the vehicle bus
interface between the radio and the FCM. When the
radio is turned on, the radio sends a PCI Bus
message to the FCM. The NBS relay is then pow-
ered on through low side control on pin 11 of the
FCM. The relay supplies power to the amplified
speaker, and ground is supplied through the radio.
This circuit is electronically controlled and contin-
uously monitored for malfunctions.
Electronic Back Light (EBL) relay
The rear defrost switch is part of the Automatic
Temperature Control or A/C-Heater Control Module
(Manual Temp). When the ignition switch is in the
RUN position and the rear defrost switch is turned
on, the ATC or A/C-Heater Control Module sends a
PCI Bus message to the FCM. The EBL run only
relay is then powered through low side control on
pin 31 of the FCM. The relay provides the high side
to the rear window defrost grid, and ground is
attached to the vehicle body. The FCM will only
allow the rear defrost to operate in the RUN posi-
tion. This circuit is electronically controlled and
continuously monitored for malfunctions.
Cabin Heater Relay
When the ignition is in Run, the FCM monitors
the PCI bus for the Cabin Heater Activation re-
quest. The A/C ± Heater Control Module initiates
this request only when all conditions for Cabin
Heater activation are favorable. The request carries
the status bit that the FCM requires to activate its
Cabin Heater Assist Control output. This output is
a low side driver (coming from FCM pin 15) which
supplies a ground signal to the Cabin Heater (pin
5). When the Cabin Heater receives this ground
signal input, it interprets this as an activation
signal. The FCM low side driver is also capable of
diagnostic sensing. The driver will sense an open
circuit when the driver is off, and will sense a short
to voltage when the driver is on. The FCM will set
DTCs for both of these types of faults. For addi-
tional information, refer to Cabin Heater under
General Information and Diagnostic Procedures in
the manual.3.8.3 ELECTRICAL INPUTS
Headlamp battery supplies1&2Ð12 volt
input on pins 1 and 2. Battery supply voltage for
switching headlamp circuits only.
Module battery supply Ð12 volt input on pin 9.
Battery supply voltage for all other FCM opera-
tions.
Power ground ÐGround source on pin 8 for all
FCM operations.
Ignition switch RUN or START position status
Ð12 volt input on pin 37. Allows the FCM to
determine the ignition switch status for related
FCM operations.
Ignition switch START only status Ð12 volt
input on pin 19. Allows the FCM to discriminate
between RUN/START input and START for related
FCM operations.
PCI Bus ÐApproximately 7.5 volt input on pin 22.
Allows the FCM to communicate with other mod-
ules on the vehicle bus.
Stop lamp Switch status Ð12 volt input on pin
44. Provides for brake shift interlock function.
Horn Switch ÐGround input on pin 17. Primary
means for engaging the horn.
Back-up switch ÐGround input on pin 39. Input
is converted to a PCI Bus status message for use by
other modules.
Wiper park switch ÐGround input on pin 16.
Used to determine park placement of wipers. Also
used as feedback to FCM to determine correct
operating mode of wipers.
Washer fluid level switch ÐGround input to
pull-up on pin 18. Ground is switched into the
circuit when washer bottle fluid level is low.
Brake fluid level switch ÐGround input to
pull-up on pin 36. Ground is switched into the
circuit when brake fluid level is low.
Ambient temperature sensor ÐResistive input
to pull-up on pin 25. Corresponding voltage level is
converted to a PCI Bus message for use by other
modules on the bus.
Right park lamp outage Ð12 volt input on pin
21. Used to determine if right park lamp circuit is
operating properly.
Left park lamp outage Ð12 volt input on pin 41.
Used to determine if left park lamp circuit is
operating properly.
Battery IOD Ð12 volt input on pin 20. The FCM
enters a low power consumption mode when the
ignition is turned OFF. This low current draw
battery supply keeps the microprocessor function-
ing in the low power mode.
Battery (+) connection detection Ð12 volt
input on pin 38. The battery connection on the PDC
incorporates the use of an internal switch to deter-
mine if the connector is properly mated and the
Connector Positive Assurance (CPA) is engaged. If
15
GENERAL INFORMATION
seconds instead of 5, the CMTC will set the
variance to 8 and enter the fast calibration
mode.
3. The VAR light will come on and the last variance
setting will be displayed.
4. Press the STEP button to set the zone number.
5. Press the US/M button and resume normal op-
eration.
NOTE: Do not attach any magnetic device
such as a magnetic CB antenna to the
vehicle. This can cause the compass to give
false readings.
3.15 POWER DOOR LOCK SYSTEM
When the BCM receives input for a lock request
from a door lock switch, RKE or cylinder lock switch
(only with VTSS), it will turn the lock driver on for
a specified time of 375 msec. If the request is there
beyond 375 msec, the BCM considers the door lock
signal stuck. Once a door lock or unlock signal is
stuck for longer than 10 seconds, the BCM will set
a trouble code and the signal input is ignored until
the stuck condition disappears. The door lock
switches provide a variable amount of resistance
thereby dropping the voltage of the multiplexed
(MUX) circuit and the BCM will respond to that
command.
3.15.1 SLIDING DOOR MEMORY LOCK
When the BCM receives an input for a lock
request and a sliding door is open, the BCM will
turn on the lock driver as described above, and will
turn it on again when all sliding doors are closed.
NOTE: If the BCM receives an unlock input before
a sliding door is closed, this will cancel the memory
lock.
3.15.2 DOOR LOCK INHIBIT
When the key is in the ignition and in any
position and either front door is open, the door lock
switches LOCK functions are disabled. The UN-
LOCK functions are still functional. This protects
against locking the vehicle with the keys still in the
ignition. The RKE key fob will still lock the doors as
usual. This allows the driver to lock the vehicle with
the engine running for warm up.
3.15.3 AUTOMATIC DOOR LOCKS
This feature can be enabled or disabled by using
either the DRBIIItor the customer programming
method. When enabled all the doors will lock when
the vehicle reaches a speed of 18 MPH (29 KMH)
and all the doors are closed. If a door is opened and
the vehicle slows to below 18 MPH (29 KMH), thedoor locks will operate again once all doors are
closed and the speed is above 15 MPH (24 KMH).
3.15.4 REMOTE KEYLESS ENTRY (RKE)
The body control module interfaces with the RKE
module via a one-way serial bus interface. The RKE
module is not on the PCI bus. The RKE module
sends a 0-5 volt pulse width signal to the BCM
depending on which button on the transmitter was
pressed. The BCM controls the door lock/unlock
functions and the arming/disarming of the Vehicle
Theft Security System (if equipped) and the activa-
tion of illuminated entry. The BCM will also send
the appropriate messages to the Power Sliding
Doors and Power Liftgate modules. The Intelligent
Power Module (IPM) activates the park lamps,
headlamps, and horn for horn chirp when sent the
appropriate message from the BCM as received
from the RKE transmitter. When a one-button
press is made for unlock, both driver side doors will
unlock and the front and rear turn signal will flash.
When a second press is initiated (within 5 seconds
of the first) both passenger doors will unlock and all
four turn signals will flash.
The RKE module is capable of retaining up to 4
individual access codes (4 transmitters). If the
PRNDL is in any position except park, the BCM will
ground the interface thereby disabling the RKE.
The 2 button transmitter will have 2-CR2016
batteries in series. The 5 button transmitter will
have 1-CR2016 battery. The minimum battery life
should be approximately 4.7 years based on 20
transmissions a day at 84ÉF (25ÉC). Using the
DRBIIItand selecting RKE FOB Test can test the
transmitter.
The RKE module can be programmed via the
DRBIIItor the customer programming method.
The BCM will only allow programming mode to be
entered when the ignition is in the on position, the
PRNDL is in park position, and the VTSS (if
equipped) is in the disarmed mode.
3.16 POWER FOLDING MIRRORS
The power folding mirrors are powered to two
positions: folded and unfolded. The driver may
choose fold or unfold with a switch that is located on
the right side of the steering column. The folding
mirror switch grounds a sense wire that comes from
the Body Control Module when it is placed in the
fold position. The mirrors will move to the position
designated by the switch whether the ignition
switch is the On or Off position and both front doors
are closed. When the Power Folding Mirror switch
is left in the fold position during a vehicle exit the
mirrors will automatically unfold then refold after
both front doors are closed. This is to prevent mirror
contact with either front door when opened. When
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GENERAL INFORMATION