Transmitter and the EVIC module are inoperative,
refer toElectronic Vehicle Information Center
Diagnosis and Testingin this group for further
diagnosis. For complete circuit diagrams, refer to
Wiring Diagrams. (Fig. 5) as described below:
(1) Turn the Radio Frequency (RF) Detector ON. A
ªchirpº will sound and the green power LED will
light. If the green LED does not light, replace the
battery.
(2) Hold the RF detector within one inch of the
TRAINED universal transmitter and press any of the
transmitters buttons.
(3) The red signal detection LEDs will light and
the tool will beep if a radio signal is detected. Repeat
this test three times.
STANDARD PROCEDURE
STANDARD PROCEDURE - SETTING
TRANSMITTER CODES
(1) Turn off the engine.
(2) Erase the codes by pressing the two outside
buttons. Release the buttons when the display con-
firms the operation (about 20 seconds).
(3) Choose one of the three buttons to train. Place
the hand-held transmitter within one inch of the uni-
versal transmitter and push the buttons on both
transmitters.(4) Release both buttons. Your universal transmit-
ter is now ªtrainedº. To train the other buttons,
repeat Step 3 and Step 4. Be sure to keep your hand-
held transmitter in case you need to retrain the uni-
versal transmitter.
STANDARD PROCEDURE - ERASING
TRANSMITTER CODES
To erase the universal transmitter codes, simply
hold down the two outside buttons until the display
confirms the operation.
NOTE: Individual channels cannot be erased. Eras-
ing the transmitter codes will erase ALL pro-
grammed codes.
REMOVAL
(1) For universal transmitter removal and installa-
tion procedure, (Refer to 8 - ELECTRICAL/OVER-
HEAD CONSOLE/COMPASS/MINI-TRIP
COMPUTER - REMOVAL and INSTALLATION).
AMBIENT TEMP SENSOR
DESCRIPTION
Ambient air temperature is monitored by the over-
head console through ambient temperature messages
received from the Front Control Module (FCM) over
the Programmable Communications Interface (PCI)
J1850 data bus circuit. The FCM receives a hard
wired input from the ambient temperature sensor.
The ambient temperature sensor is a variable resis-
tor mounted to a bracket that is secured with a screw
to the right side of the headlamp mounting module
grille opening, behind the radiator grille and in front
of the engine compartment.
For more information on the Front Control Module
refer to the Electronic Control Modules section of this
manual. For complete circuit diagrams, refer to the
appropriate wiring information. The ambient temper-
ature sensor cannot be adjusted or repaired and, if
faulty or damaged, it must be replaced.
OPERATION
The ambient temperature sensor is a variable
resistor that operates on a five-volt reference signal
sent to it by the Front Control Module. The resis-
tance in the sensor changes as temperature changes,
changing the temperature sensor signal circuit volt-
age to the Front Control Module. Based upon the
resistance in the sensor, the Front Control Module
senses a specific voltage on the temperature sensor
signal circuit, which it is programmed to correspond
to a specific temperature. The Front Control Module
Fig. 5 RADIO FREQUENCY DETECTOR
1 - SIGNAL DETECTION LED'S
2 - POWER LED
3 - ON/OFF SWITCH
4 - 9V BATTERY
RSMESSAGE SYSTEMS8M-11
UNIVERSAL TRANSMITTER (Continued)
ProCarManuals.com
then sends the proper ambient temperature mes-
sages to the EVIC, CMTC over the PCI J1850 data
bus.
The thermometer function is supported by the
ambient temperature sensor, a wiring circuit, the
Front Control Module, the Programmable Communi-
cations Interface (PCI) data bus, and a portion of the
Electronics module. If any portion of the ambient
temperature sensor circuit fails, the Front Control
Module will self-diagnose the circuit.
The ambient temperature sensor circuit can also be
diagnosed by referring toDiagnosis and Testing -
Ambient Temperature Sensor, and Diagnosis
and Testing - Ambient Temperature Sensor Cir-
cuit. If the temperature sensor and circuit are con-
firmed to be OK, but the temperature display is
inoperative or incorrect, refer toDiagnosis and
Testing - Overhead Consolein this group. For
complete circuit diagrams, refer to the appropriate
wiring information.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector.
(2) Measure the resistance of the ambient temper-
ature sensor. At ±40É C (±40É F), the sensor resis-
tance is 336.6 kilohms. At 60É C (140É F), the sensor
resistance is 2.49 kilohms. The sensor resistance
should read between these two values. If OK, refer to
Diagnosis and Testing - Ambient Temperature
Sensor Circuitin this group. If not OK, replace the
faulty ambient temperature sensor.
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR CIRCUIT
(1) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Disconnect the ambient temperature sensor wire har-
ness connector and the Front Control Module wire
harness connector.(2) Connect a jumper wire between the two termi-
nals in the body half of the ambient temperature sen-
sor wire harness connector.
(3) Check for continuity between the sensor return
circuit and the ambient temperature sensor signal
circuit cavities of the Front Control Module wire har-
ness connector. There should be continuity. If OK, go
to Step 4. If not OK, repair the open sensor return
circuit or ambient temperature sensor signal circuit
to the ambient temperature sensor as required.
(4) Remove the jumper wire from the body half of
the ambient temperature sensor wire harness con-
nector. Check for continuity between the sensor
return circuit cavity of the Front Control Module
wire harness connector and a good ground. There
should be no continuity. If OK, go to Step 5. If not
OK, repair the shorted sensor return circuit as
required.
(5) Check for continuity between the ambient tem-
perature sensor signal circuit cavity of the Front
Control Module wire harness connector and a good
ground. There should be no continuity. If OK, refer to
Diagnosis and Testing - Overhead Consolein
this group. If not OK, repair the shorted ambient
temperature sensor signal circuit as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) From behind front bumper fascia, remove
screw holding sensor to radiator closure panel.
(3) Disconnect the sensor electrical connector.
Depress the connector retaining tab and pull the con-
nector straight off the ambient temperature sensor.
(4) Remove sensor from vehicle.
INSTALLATION
(1) Position the sensor in the vehicle and connect
the sensor electrical connector.
(2) From behind the front bumper fascia, install
the screw holding sensor to radiator closure panel.
(3) Connect the battery negative cable.
8M - 12 MESSAGE SYSTEMSRS
AMBIENT TEMP SENSOR (Continued)
ProCarManuals.com
POWER LIFTGATE SYSTEM
DESCRIPTION
Some vehicles are equipped with an automatic
opening and closing power liftgate system (Fig. 1).
This power liftgate system is a complex system con-
sisting of many components. Some of these compo-
nents are the liftgate gear motor assembly, latch
assembly, lift gear and rod, liftgate control module,
chime/thermistor, full open switch, engage actuator,
pinch sensor, liftgate handle switch, overhead console
switch, key fob switches (Fig. 2), pawl switch and
ratchet switch.
The power liftgate system has its own door control
module, located on the vehicles left body D-pillar
behind the trim panel. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/DOOR CON-
TROL MODULE - DESCRIPTION) The power
liftgate gear motor assembly is located just above the
control module. The latch assembly is located in the
bottom center of the power liftgate, below the exte-
rior liftgate handle switch. The power liftgate full
open switch, engage actuator, lift gear and rod are
part of the liftgate gear motor assembly. The pawl
and ratchet switches are part of the latch assembly.
The pinch sensor or sensors are located along theright and left sides of the power liftgate, just above
the body line. The liftgate handle switch is an power
release switch and is located in the rear light bar
assembly, just above the license plate. The overhead
console switch is an power open and close command
switch located in the vehicles overhead console.
Safety is of the utmost concern with the power lift-
gate system. Software technology has enabled the
power liftgate control module to detect resistance to
liftgate travel, which allows the power liftgate to stop
and reverse direction anytime an obstruction is felt
or any of the command switches are operated (only in
closing direction). Battery voltage is supplied to the
power liftgate system through a 40 amp fuse, located
in the Intelligent Power Module (IPM) assembly (Fig.
3). In the unlikely event that the power liftgate sys-
tem develops a fault the power liftgate can still be
operated manually with a key, just like a standard
manual liftgate.
The power liftgate control module communicates
on the J1850 Programmable Communication Inter-
face (PCI) Bus Circuit. Therefore, the power liftgate
control module can generate and store its own Diag-
nostic Trouble Codes (DTC). The vehicles Body Con-
trol Module (BCM) receives and supplies messages to
the power liftgate control module via the PCI bus cir-
cuit. A diagnostic scan tool, such as the DRB IIItis
Fig. 1 POWER LIFTGATE INTRODUCTION
8N - 2 POWER LIFTGATE SYSTEMRS
ProCarManuals.com
assembly in the rear light bar assembly monitors the
outside temperature.
²The vehicle transmission must be in Park or
Neutral for the power liftgate to start a cycle.
²If multiple obstacles are detected during the
same power open or close cycle, the liftgate goes into
manual operation.
²If severe problems occur, Diagnostic Trouble
Codes (DTC) are stored in the power liftgate control
module.
POWER LIFTGATE SYSTEM CAUTIONS AND
WARNINGS
WARNING: ALWAYS DISCONNECT THE NEGATIVE
BATTERY CABLE BEFORE ATTEMPTING ANY
POWER LIFTGATE SYSTEM SERVICE.
WARNING: THERE IS A SMALL AREA ON BOTH
SIDES OF THE LOWER POWER LIFTGATE WHICH
ARE NOT PROTECTED BY PINCH SENSORS.
EXTREME CARE MUST BE TAKEN TO PREVENT
OBJECTS FROM ENTERING THIS AREA ONCE THE
LIFTGATE REACHES THE SECONDARY LATCH
CONTACT (APPROXIMATELY 1/2 INCH BEFORE
FULLY CLOSED).
WARNING: NEVER ATTEMPT TO ENTER OR EXIT
THE VEHICLE WITH THE LIFTGATE IN MOTION.
YOU COULD DAMAGE THE POWER LIFTGATE SYS-
TEM AND/OR COMPONENTS AND/OR CAUSE PER-
SONAL INJURY.
WARNING: NEVER STICK OBJECTS IN THE POWER
LIFTGATE WHEN CINCHING CLOSED. YOU COULDDAMAGE THE VEHICLE, POWER LIFTGATE SYS-
TEM COMPONENTS AND/OR CAUSE PERSONAL
INJURY.
DIAGNOSIS AND TESTING - POWER LIFTGATE
SYSTEM
The power opening and closing power liftgate sys-
tem is a complex system containing many compo-
nents and modules. In order to obtain conclusive
testing the Programmable Communications Interface
(J1850) data bus network and all of the electronic
modules that provide inputs to, or receive outputs
from the power liftgate system must be checked.
The power liftgate system was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the power liftgate system
requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual. The
DRB IIItcan be used to observe various switch sta-
tuses throughout the power liftgate system to help
the technician diagnose a defective switch or compo-
nent. The DRB IIItcan also be used to actuate var-
ious components throughout the power liftgate
system to help the technician diagnose a defective
component.
Before any testing of the power liftgate system is
attempted, the battery should be fully charged, all
built-in power liftgate system inhibitors read and
understood (Refer to power liftgate system operation)
and all wire harness and ground connections
inspected around the affected areas on the vehicle.
Following are quick reference diagnostic tables to
help when diagnosing and testing the power liftgate
system.
8N - 4 POWER LIFTGATE SYSTEMRS
POWER LIFTGATE SYSTEM (Continued)
ProCarManuals.com
LIFTGATE SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
Liftgate opens unexpectedly Failure of Power Liftgate or Body
Control moduleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of latch assembly Check wiring connections and for blown
fuse
Check for trouble codes, replace latch if
necessary
Failure of open/close command
switchCheck for shorted or defective switch
Liftgate will not open from
outside of vehicle manuallyFailure of key cylinder assembly Check for broken key cylinder assembly
Check link rod connections at the latch and
key cylinder assembly
Check for binds or kinks in link rod
Check for foreign matter preventing the
operation of key cylinder assembly
Replace the necessary components
Failure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Replace latch assembly, if necessary
Binding or sticking of components Check for foreign matter preventing the
operation of door
Establish location of binding
Replace necessary components
Liftgate will not open/close
under powerFailure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Troubleshoot using Body Diagnostic
Manual Replace latch assembly, if
necessary
Failure of motor assembly Troubleshoot using Body Diagnostic
Manual
Failure of full open switch Troubleshoot using Body Diagnostic
Manual
RSPOWER LIFTGATE SYSTEM8N-5
POWER LIFTGATE SYSTEM (Continued)
ProCarManuals.com
CONDITION POSSIBLE CAUSES CORRECTION
Binding or sticking of components Establish location of binding and replace
necessary components
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Power loss during Liftgate
operationWiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Low battery voltage Charge battery
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of motor assembly Check for no drive condition
No power latching in
primary and/or secondary
positionsFailure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Troubleshoot using Body Diagnostic
Manual. Replace latch assembly, if
necessary
Binding or sticking of components Establish location of binding and replace
necessary components
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Door seal force too high Inspect seals for damage, mis-assembly,
foreign matter or other possible obstruction
Failure of motor assembly Check for no drive condition
Latch will not fully release
from primary positionFailure of latch assembly Check wire connections and for blown fuse
Check for foreign matter or damaged
components preventing the operation of
latch assembly
Troubleshoot using body electrical
troubleshooting manual Replace latch
assembly, if necessary
Failure of outside handle switch Troubleshoot using Body Diagnostic
Manual Replace switch, if necessary
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Binding or sticking of components Establish location of binding and replace
necessary components
8N - 6 POWER LIFTGATE SYSTEMRS
POWER LIFTGATE SYSTEM (Continued)
ProCarManuals.com
CONDITION POSSIBLE CAUSES CORRECTION
Key fob, Outside Handle or
overhead console switches
do not power operate
liftgateBlown Fuse Check fuse and replace
Battery voltage low Charge or replace battery in key fob or
vehicle
Failure of latch assembly Check for foreign matter preventing the
operation of latch assembly
Check wire connection
Pawl and/or ratchet switch inoperative
Replace latch if necessary
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Failure of Body Control Module
(BCM)Check electrical connections
Refer to the Body electrical troubleshooting
guide for additional checks
Replace BCM if necessary
Failure of key fob Reprogram key fob
Replace key fob if necessary
Failure of Power Liftgate Module Disconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of liftgate motor assembly Check for foreign matter preventing the
operation of gear motor assembly
Check wire connections
Motor clutch does not engage, replace
assembly
Full open switch inoperative, replace
switch, if necessary
Troubleshoot using Body Diagnostic
Manual Replace motor, if necessary
Liftgate does not stay open Failure of liftgate prop rods Replace prop rods, if necessary
Check for broken attachments
High inside/outside opening
effortFailure of liftgate prop rods Replace prop rods, if necessary
Check for broken attachments
Gear motor did not disengage Troubleshoot using Body Diagnostic
Manual Replace components, if necessary
Binding or sticking of components Establish location of binding and replace
necessary components
RSPOWER LIFTGATE SYSTEM8N-7
POWER LIFTGATE SYSTEM (Continued)
ProCarManuals.com
CONDITION POSSIBLE CAUSES CORRECTION
Liftgate continues to cinch
closed during power modeFailure of latch assembly Check wire connections and for blown fuse
Check for foreign matter preventing the
operation of latch assembly
Troubleshoot using Body Diagnostic
Manual Replace components, if necessary
Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to wiring diagrams
Liftgate continues to open
during power mode
(runaway motor)Failure of Power Liftgate or Body
Control ModuleDisconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Manual for detailed
procedures
Failure of full open switch Check wire connections
Replace switch, if necessary
Failure of motor assembly Check for continuous drive condition
Wiring problems (system or vehicle) Troubleshoot using electrical schematics.
Refer to Wiring Diagrams
Liftgate opens very slowly Failure of liftgate motor assembly Check wire connections
Replace motor assembly, if necessary
Failure of liftgate prop rods Replace prop rods, if necessary
Binding or sticking of components Establish location of binding and replace
necessary components
Grade of vehicle too steep for power
operationOperate liftgate manually
Squeaks, Noises and rattles Foreign material in door
compartmentRemove foreign material
Loose components Check and tighten loose components
8N - 8 POWER LIFTGATE SYSTEMRS
POWER LIFTGATE SYSTEM (Continued)
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