2001 CHRYSLER VOYAGER relay

section 7.0. This will direct you to the specific test(s)
that must be performed. Active diagnostic trouble
codes for the airbag system are not permanent and
will change the moment the reason for the code is
corrected. In certain test procedures within this
manual, diagnostic trouble codes are used as a
diagnostic tool.
3.1.9 ACTIVE CODES
The code becomes active as soon as the malfunc-
tion is detected or key-on, whichever occurs first. An
active trouble code indicates an on-going malfunc-
tion. This means that the defect is currently there
every time the airbag control module checks that
circuit or component. It is impossible to erase an
active code. Active codes automatically erase by
themselves when the reason for the code has been
corrected. With the exception of the warning lamp
trouble codes or malfunctions, when a malfunction
is detected, the airbag lamp remains lit for a mini-
mum of 12 seconds or as long as the malfunction is
present.
3.1.10 STORED CODES
Airbag codes are automatically stored in the
ORC's memory as soon as the malfunction is de-
tected. The exception is the Loss of Ignition Run
Only code which is an active code only. A stored code
indicates there was an active code present at some
time. However, the code currently may not be
present as an active code, although another code
could be active. When a trouble code occurs, the
airbag warning indicator illuminates for 12 seconds
minimum (even if the problem existed for less than
12 seconds). The code is stored, along with the time
in minutes it was active, and the number of times
the ignition has been cycled since the problem was
last detected. The minimum time shown for any
code will be one minute, even if the code was
actually present for less than one minute. Thus, the
time shown for a code will be one minute, even if the
code was actually present for less than one minute.
Thus, the time shown for a code that was present
for two minutes 13 seconds, for example, would be
three minutes. If a malfunction is detected a diag-
nostic trouble code is stored and will remain stored.
When and if the malfunction ceases to exist, an
ignition cycle count will be initiated for that code. If
the ignition cycle count reaches 100 without a
reoccurrence of the same malfunction, the diagnos-
tic trouble code is erased and that ignition cycle
counter is reset to zero. If the malfunction reoccurs
before the count reaches 100, then the ignition cycle
counter will be reset and diagnostic trouble code
will continue to be a stored code. If a malfunction is
not active while performing a diagnostic test proce-
dure, the active code diagnostic test will not locatethe source of the problem. In this case, the stored
code can indicate an area to inspect. If no obvious
problems are found, erase stored codes, and with
the ignition on wiggle the wire harness and connec-
tors, rotate the steering wheel from stop to stop.
Recheck for codes periodically as you work through
the system. This procedure may uncover a malfunc-
tion that is difficult to locate.
3.2 AUDIO SYSTEM
The following radios are all on the PCI Bus
system - RBB, RBK, RAZ, RAD, RBT, and RBY. The
remaining radio also available, the RAS, is NOT on
the PCI Bus. The PCI Bus inputs into the radio are
used for VF dimming, remote steering wheel con-
trols and cabin EQ preference. PCI Bus outputs
from the radio are used for the Name Brand
Speaker (NBS) relay activation, as well as cabin EQ
preference.
The RBB and RBK radios have the capability of
containing multiple vehicle unique equalization
curves (cabin EQ preferences) within the radio.
These curves will reside in the radio's flash memory.
The radio is capable of storing up to 20 unique
equalization curves. The latent curves can be se-
lected via the Front Control Module transmitting a
PCI Bus message to the radio in response to a radio
request for equalization message. Upon receipt of a
valid equalization select message response, the ra-
dio will switch to output the corresponding equal-
ization curve.
All the radios, except the RAS, are capable of
displaying faults and allowing certain actuation
tests through the use of the DRBIIIt. When at-
tempting to perform PCI Bus diagnostics, the first
step is to identify the radio in use in the vehicle.
When trouble shooting output shorts or ªoutputº
error messages, the following applies:
On radios without an external amplifier, the term
output refers to the path between the radio and the
speaker. This type of circuit can be monitored all
the way through the speaker connections by the
radio assembly. When the radio displays a shorted
output DTC with this type of system, the speaker,
radio, or wiring could be at fault. The output DTC
could refer to the front or rear output or a left or
right output. The reason for the difference is the
pairing of the output sections of the radio. Some are
paired left and right, others are paired front and
rear.
On radios with an external amplifier, the term
ªoutputº refers to the circuit between the radio
connector and the amplifier. The radio is capable of
monitoring only this portion and can tell nothing
about the circuit between the amplifier and the
speakers. Consequently, a shorted output DTC on
7
GENERAL INFORMATION

3.6 DOOR AJAR SYSTEM
The door ajar and liftgate ajar states are used as
inputs for the Body Control Module (BCM). The
BCM uses these inputs to determine exactly what
position the doors and liftgate are in. The DRBIIIt
will display the state of the door ajar and the
liftgate ajar switches in Inputs/Outputs. It's impor-
tant to note, that when any door, or the liftgate is
closed, the switch state on the DRBIIItwill show
OPEN. When any door, or the liftgate is open the
switch state on the DRBIIItwill show CLOSED.
During diagnosis, if a door or the liftgate is closed
and the DRBIIItdisplays the switch state as
CLOSED, it indicates a shorted ajar circuit. If the
door or the liftgate is open and the DRBIIItdis-
plays the switch state as OPEN, it indicates an
open ajar circuit.
3.7 EXTERIOR LIGHTING SYSTEM
3.7.1 HEADLAMP POWER
The headlamp switch is a direct input to the
BCM. The BCM sends a 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 continuously moni-
tored for malfunctions. Power is supplied to each
filament in a separate circuit. For vehicles equipped
with daytime running Lamps (DRL), the FCM elec-
tronically steps down the headlamp voltage to pro-
vide the desired illumination.
3.7.2 HEADLAMP SWITCH
The Headlamp Switch uses a multiplexed (MUX)
circuit to the Body Control Module (BCM). The
Headlamp Switch controls the Fog lamp relay, Park
lamps and the Low and High headlamps. The BCM
then sends a signal through the PCI Bus line to the
FCM as to what state the switch has selected. The
FCM energizes the high side output drivers to turn
ON the desired lamps.
3.7.3 PARK LAMP RELAY
The park lamp switch is a direct input to the
BCM. The BCM sends a BUS message to the FCM
informing it to turn on the park lamp relay. The
park lamp relay is then powered through low side
control of the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions.
3.7.4 FOG LAMP RELAY
The fog lamp switch is a direct input to the BCM.
The BCM sends a BUS message to the FCM inform-
ing it to turn on the fog lamp relay. The fog lamp
relay is then powered through low side control of
the FCM. This circuit is electronically controlled
and continuously monitored for malfunctions. Fog
lamp functionality is not equipped on all vehicles.
The FCM ªlearnsº that the vehicle is equipped with
fog lamps by reading the BCM BUS message.
3.7.5 FOG LAMPS
The BCM controls the operation of the fog lamp
relay that turns the fog lamps ON and OFF. The
Fog lamps can only be ON when the park and low
beams are ON. If the high beams are switched ON
then the Fog lamps will be automatically turned
OFF.
12
GENERAL INFORMATION

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

EATX power
The electronic automatic 4 speed transmission
module is powered when the ignition switch is in
the UNLOCK, RUN or START positions. This cir-
cuit is electronically controlled and continuously
monitored for malfunctions. Power is supplied
through pin 27 of the FCM connector.
Front washer motor
The front washer switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it of a request to wash. The front
washer motor is then powered through low side
control inside the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. In addition, the FCM electronically protects
the washer motor from system voltages higher than
16 volts by automatically switching off the low side
circuit. The low side circuit is connected to pin 45 in
the FCM connector.
Rear washer motor
The rear washer switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it of a request to wash. The rear
washer motor is then powered through low side
control inside the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. In addition, the FCM electronically protects
the washer motor from system voltages higher than
16 volts by automatically switching off the low side
circuit. The low side circuit is connected to pin 46 in
the FCM connector.
Brake shift interlock system
The brake shift interlock solenoid receives power
from both high side and low side controls inside the
FCM. The high side control is on the same circuit as
the EATX module power, and the low side control
comes through pin 47 of the FCM connector. The
solenoid is controlled by the low side driver when
the brake pedal is pressed. Both circuits are contin-
uously monitored for malfunctions.
3.8.2 RELAY CONTROLS
Fog lamp relay
The fog lamp switch is a direct input to the BCM.
The BCM sends a PCI Bus message to the FCM
informing it to turn on the fog lamp relay. The fog
lamp relay is then powered through low side control
on pin 33 of the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. Fog lamp functionality is not equipped on all
vehicles. The FCM ªlearnsº that the vehicle is
equipped with fog lamps by reading the BCM PCI
Bus message.
Park lamp relay
The park lamp switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it to turn on the park lamp relay.
The park lamp relay is then powered through lowside control on pin 13 of the FCM. This circuit is
electronically controlled and continuously moni-
tored for malfunctions.
Front wiper on relay
The front wiper switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it to turn on the front wiper on
relay. The front wiper on relay is then powered
through low side control on pin 14 of the FCM. This
circuit is electronically controlled and continuously
monitored for malfunctions.
Front wiper high/low relay
The front wiper switch is a direct input to the
BCM. The BCM sends a PCI Bus message to the
FCM informing it to turn on the front wiper high/
low relay. The relay switches power between the low
speed and high speed windings of the wiper motor.
The front wiper high/low relay is powered through
low side control on pin 34 of the FCM. This circuit is
electronically controlled and continuously moni-
tored for malfunctions.
Accessory relay
The accessory relay works in conjunction with the
FCM's power accessory delay feature to control the
operation of the radio, power windows, washer
motors, wiper motors and power outlet. The acces-
sory relay is turned on through low side control on
pin 35 of the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. Depending on the ignition switch position,
the accessory relay will remain on or will time-out
and turn off. The accessory relay remains on in the
RUN and ACCY positions of the ignition switch. In
the UNLK and OFF positions, the relay will remain
energized for 45 seconds then turn off. During this
time-out period, if the driver or passenger doors are
opened, the relay will turn off immediately. While
the ignition switch is in the START position, the
relay will also drop-out, then resume operation.
Accessory relay operation is most noticeable by
observing the operation of the radio or blower
functions.
Horn relay
The horn relay operates through a direct wire
input to the FCM from the horn switch (FCM pin
17) , or a PCI Bus message from the BCM. The relay
responds to the horn switch, remote door lock and
VTA alarm functions. The horn relay is powered
through low side control on pin 10 of the FCM.
Under normal operating conditions, if the horn is
pressed for longer than 30 seconds, the FCM will
automatically deactivate the horn to prevent dam-
age to it. The FCM will re-activate control of the
relay after a 25 second cool-down period. This
circuit is electronically controlled and continuously
monitored for malfunctions.
14
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

the CPA is not properly engaged, a voltage on pin 38
will be interpreted as an unseated connector and a
fault will set.
Flash programming voltage Ð20 volt input on
pin 42. When a DRBIIItis connected and the
proper flash reprogramming sequence is selected,
the 20 volt signal will be applied through pin 42.
3.9 HEATING & A/C
3.9.1 AUTOMATIC TEMPERATURE
CONTROL (ATC)
3.9.1.1 CABIN HEATER
For vehicles equipped with a diesel engine, a
Cabin Heater is used in conjunction with the HVAC
system. The Cabin Heater is designed to supply the
vehicle's occupants with heat prior to the engine
reaching operating temperature. For additional in-
formation on this system, refer to Cabin Heater
under General Information and Diagnostic Proce-
dures in this manual.
3.9.1.2 SYSTEM OPERATION
The Automatic Temperature Control (ATC) sys-
tem provides fully adjustable three zone climate
control; Driver front zone, Passenger Front zone
and Rear zone. The following is a list of ATC
controls and features:
± a POWER button which allows the operator to
turn the system completely off.
± AUTO HIGH/LOW switch allows the operator
to select what rate (fan speed) the system will
provide the selected comfort level.
± DRIVER, REAR and PASSENGER rocker
switches to select desired temperature for each
zone.
± Recirculation button allows cooling air to be
recirculated which maximizes cooling ability.
± A/C select button allows the operator to turn
the A/C compressor off.
± Defroster button allows the operator to turn on
the defroster independently during automatic
control.
± Fan control rotary switch for selecting fan
speed.
± Mode rotary switch for selecting heating/
cooling direction.
± REAR SYSTEM rotary switch for activating
the Rear ATC Switch allowing intermediate
passenger control over rear climate control.
3.9.1.3 BLOWER MOTOR OPERATION
The Automatic Temperature Control (ATC) front
and rear blower control provides continuously vari-
able control of air flow rate to meet occupant
comfort requirements. Pulse width modulation of
the blower motor power allows the front and rear
blower to operate at any speed from off to full speed.
When front or rear blower operation is required, the
ATC sends a PCI Bus message to the Front Control
Module (FCM) requesting blower relay ON. The
FCM provides a ground for the front and rear
blower motor relay coils, activating both relays. The
front and rear blower relays provide 12 volts to
their respective blower motor power modules. Each
module provides a 12 volt blower motor control
signal to the ATC. The ATC provides a pulse width
modulated (duty-cycle) ground signal to this circuit
based on climate requirements. The higher voltage
on the signal circuit (less duty-cycle ground) the
lower the blower speed request. The lower voltage
on the signal circuit (more duty-cycle ground) the
higher the blower speed request.
3.9.1.4 INFRARED SENSORS
The ATC system uses infrared (I/R) sensors to
monitor and control oocupant comfort levels. This
sensing system replaces interior air temperature
and solar sensors which required complex control
programs to maintain occupant comfort levels. The
front I/R sensor is located in the instrument panel
center bezel outlet. The rear I/R sensor is located in
the rear overhead mounted ATC switch.
3.9.1.5 REAR ATC SWITCH
The rear ATC switch is mounted in the headliner.
The switch contains a rotary adjustment for fan
speed, a rotary adjustment for mode selection, a
push button switch for temperature selection and a
digital display of the selected temperature.
3.9.1.6 COOLDOWN TESTING
The ATC provides a feature referred to as a
Cooldown Test. This test is initiated using the
DRBIIItand is designed to check the performance
of the air conditioning system. The ATC will not
perform this test if the ambient air temperature is
below 12ÉC (53ÉF). During the test, the ATC com-
pares the ambient air temperature to the evapora-
tor temperature sensor. To pass the cooldown test,
the evap temperature sensor must drop -6ÉC (20ÉF)
below ambient temperature within 2 minutes of
start of test. At the completion of the cooldown test
the DRBIIItwill display one of the following mes-
sages indicating test outcome:
± Cooldown Test Passed
± Cooldown Test Failed
16
GENERAL INFORMATION

3.9.2.8 HVAC SYSTEM RELAYS
The Integrated Power Module (IPM) houses and
provides power to the A/C Clutch Relay and Front
Blower Motor Relay.
3.9.2.9 EVAPORATOR TEMPERATURE
SENSOR
An evaporator temperature sensor, located on the
A/C expansion valve under the hood, replaces the
previously used fin sensor.
3.9.2.10 A/C ± HEATER CONTROL
MODULE, SWITCH OPERATION
Power Switch
The Power Switch is a momentary contact switch.
The switch LED illuminates when the switch is on.
The Power Switch setting is remembered during
power down.
Rear Window Defogger Switch
The Rear Window Defogger Switch is a momen-
tary contact switch. Toggling the switch results in
the A/C ± Heater Control Module sending a change
of state message to the FCM to provide rear window
defogger activation or deactivation respectively.
The switch LED illuminates when the switch is on.
Recirculation Switch
The Recirculation Switch is a momentary contact
switch. Toggling the switch on results in the A/C ±
Heater Control Module signaling the actuator to
close the fresh-air door. Toggling the switch off
results in the A/C ± Heater Control Module signal-
ing the actuator to open the fresh-air door. The
switch LED illuminates when the switch is on.
When the Power Switch is off, the A/C ± Heater
Control Module closes the fresh-air door to prevent
outside air from entering the passenger compart-
ment. The recirculation mode will cancel whenever
defrost is requested. Pressing the Recirculation
Switch while in defrost mode will illuminate the
Recirculation Switch LED, but only while the but-
ton is pressed. Under this circumstance, the recir-
culation request will be denied and the fresh-air
door will remain in the fresh position. All door
positions are determined relative to the number of
commutator pulses required to provide full travel of
the door. On command, the A/C ± Heater Control
Module runs the actuator for the number of pulses
corresponding to the desired door position.
A/C Switch
The A/C Switch is a momentary contact switch.
Toggling the switch results in the A/C ± Heater
Control Module sending a change of state message
to the Powertrain Control Module (PCM ± gasoline)or Engine Control Module (ECM ± diesel) to provide
A/C compressor clutch activation or deactivation
respectively. The A/C ± Heater Control Module will
only provide this request if EVAP function is found
acceptable. The Power Switch must be on to make
the A/C switch active. The switch LED illuminates
when the switch is on. The A/C Switch setting is
remembered during power down.
Blower Switch
The rotary Blower Switch has five positions, Low,
M1, M2, M3, and High. The Power Switch must be
on to make the Blower Switch active. Toggling the
Power Switch results in the A/C ± Heater Control
Module sending a request to the FCM to provide
blower motor activation or deactivation respec-
tively.
Blend Switch ± Single Zone
The single rotary Blend Switch has multiple
detents to control the full range of temperature that
the system can produce in any mode. Rotating the
switch results in the A/C ± Heater Control Module
signaling the actuator to move the blend door. All
door positions are determined relative to the num-
ber of commutator pulses required to provide full
travel of the door. On command, the A/C ± Heater
Control Module runs the actuator for the number of
pulses corresponding to the desired door position.
Blend Switch ± Dual Zone
The dual sliding Blend Switches have multiple
detents to control the full range of temperature that
the system can produce an any mode. The upper
slide pot controls the driver-side blend door, while
the lower slide pot controls the passenger-side
blend door. Sliding the switch results in the A/C ±
Heater Control Module signaling the actuator to
move the blend door. All door positions are deter-
mined relative to the number of commutator pulses
required to provide full travel of the door. On
command, the A/C ± Heater Control Module runs
the actuator for the number of pulses corresponding
to the desired door position.
Mode Switch
The single rotary Mode Switch has 13 detents to
either direct airflow to the panel outlets, a mix of
floor and panel outlets, floor outlets, a mix of floor
and defrost outlets, or defrost outlets. Rotating the
switch results in the A/C ± Heater Control Module
signaling the actuator to move the mode door. All
door positions are determined relative to the num-
ber of commutator pulses required to provide full
travel of the door. On command, the A/C ± Heater
Control Module runs the actuator for the number of
pulses corresponding to the desired door position.
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GENERAL INFORMATION

opening either front door, the Body Control Module
will unfold the mirrors in the following manner
depending on which front door is opened. If the
driver door is opened, only the driver side mirror
will unfold. If the passenger door is opened, both
mirrors will unfold. The passenger mirror is pre-
vented from unfolding when the driver 's door is
opened by the Passenger Folding Mirror Relay,
which opens the driver circuit to the passenger side
mirror.
3.17 POWER LIFTGATE SYSTEM
3.17.1 POWER LIFTGATE
The power liftgate (PLG) system is activated
through the use of the following: remote keyless
entry (RKE), overhead console switches, outside
liftgate handle switch or the DRBIIIt. These inputs
are hardwired to the body control module (BCM)
and can be monitored with a diagnostic tool. The
BCM will send the message via PCI bus to the
power liftgate module (PLGM). The liftgate must be
in the full open or full closed position to operate.
Once the BCM sends a button activation message to
the PLGM, the module shall read all inputs, out-
puts and vehicle conditions to determine whether it
shall open, close or inhibit the PLG operation. Once
the PLGM determines the vehicle conditions are
safe for operation, the PLGM will initiate a chime
for 2 seconds prior to the liftgate activation and 2
seconds during the open or close cycle.
During an opening or closing cycle, the PLGM can
detect an obstacle present should it meet sufficient
resistance by the hall effect sensors (integrated in
the gear motor assembly GMA).
During an open cycle, multiple liftgate activa-
tions (RKE, overhead console, B pillar) are ignored
until the liftgate reaches the full open position.
However, during a close cycle, a 2nd liftgate activa-
tion (RKE, overhead console, B pillar) will reverse
the liftgate to the full open position.
If the engine is cranked during a power open/close
the PLG will pause then resume after engine crank-
ing. In addition, if the vehicle is placed in gear
during an open cycle, the PLG shall reverse direc-
tion and begin closing. If the vehicle is placed in
gear during a closing cycle, the PLG shall continue
closing until fully closed. If the outside handle is
activated during an open cycle, the PLG will become
a full manual liftgate. If the outside handle is
activated during a close cycle, the PLG shall reverse
direction of travel to the full open position.
3.17.2 DIAGNOSTIC FEATURES
The PLG can be flashed on vehicle via PCI bus
with a DRBIIItdiagnostic tool. The DRBIIItcanread all inputs, actuate all outputs, read module
information, and read diagnostic trouble codes. As a
reminder, some DTC's can be set during normal
PLG operation.
3.17.3 SYSTEM INHIBITORS
1. Battery voltage too high or too low (above 16V,
below 9.5V)
2. Vehicle in gear
3. Vehicle speed > 0 mph/km/h
4. Outside temperature too high, above 143ÉF
(62ÉC) or too low, below -12ÉF (-24ÉC).
5. O/H console lockout will inhibit the B pillar
switches only.
6. Liftgate locked will inhibit all interior switches
from opening (overhead console). A locked lift-
gate can be power closed.
7. Pinch Sensor switch stuck shall inhibit the
power close feature.
3.18 POWER SLIDING DOOR SYSTEM
3.18.1 POWER SLIDING DOOR
The Power Sliding Door (PSD) system is acti-
vated through the use of the following: Remote
Keyless Entry (RKE), overhead console switches, B
pillar switches or the DRBIIIt. These inputs are
hardwired to the body control module (BCM) and
can be monitored with a diagnostic tool. The BCM
will send the message via PCI bus to the power
sliding door module (PSDM). The sliding door must
be in the full open or full closed position to operate.
Once the BCM sends a button activation message to
the PSDM, the module shall read all inputs, out-
puts and vehicle conditions to determine whether it
shall open, close or inhibit the PSD operation.
During an opening or closing cycle, the PSDM can
detect an obstacle present should it meet sufficient
resistance by the hall effect sensors (integrated in
the drive motor).
During an open cycle, multiple door activations
(RKE, overhead console, B pillar) are ignored until
the door reaches the full open position. However,
during a close cycle, a 2nd door activation (RKE,
overhead console, B pillar) will reverse the door to
the full open position.
If the engine is cranked during a power open/close
the PSD will pause then resume after engine crank-
ing. In addition, if the vehicle is placed in gear
during an open cycle, the PSD shall reverse direc-
tion and begin closing. If the vehicle is placed in
gear during a closing cycle, the PSD shall continue
closing until fully closed.
If the inside or outside handle is activated during
an open or close cycle, the PSD will become a full
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GENERAL INFORMATION