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CS
POWER LIFTGATE SYSTEM (Continued)
WARNING: NEVER STICK OBJECTS IN THE POWER
LIFTGATE WHEN CINCHING CLOSED. YOU COULD
DAMAGE THE POWER LIFTGATE SYSTEM AND/OR
COMPONENTS
AND/OR
INJURY.
OPERATION
Battery voltage is supplied to the power liftgate
system through a 40 amp fuse, located in the Inte-
grated Power Module (IPM) assembly. With the push
of a power liftgate open/close command switch (key
fob or overhead console mounted), a signal is sent out
on the PCI Data Bus circuit. This signal is detected
at the Body Control Module (BCM). The BCM then
adds system status and sends a signal out on the
PCI Data Bus circuit to the power liftgate control
module. The power liftgate control module then inter-
prets the information to confirm safety requirements
are met before applying power to the power liftgate
motor to start a power cycle.
During a power liftgate open or close cycle, if the
power liftgate control module detects sufficient resis-
tance to liftgate travel, such as an obstruction in the
liftgate's path. The control module will immediately
stop liftgate movement and reverse the direction of
travel to the full open or closed position. The ability
for the power liftgate control module to detect resis-
tance to liftgate travel is accomplished by the optical
and pinch sensors.
The power liftgate control module has the ability to
relearn. After 8 miles have been recorded on the
odometer, anytime the liftgate is fully opened and
fully closed using the automatic system, the module
will learn from its cycle. If a replacement power lift-
gate component is installed or a liftgate adjustment
CONDITION
Liftgate opens unexpectedly
Liftgate will not open/close
automatically
CAUSE
PERSONAL
LIFTGATE SYSTEM DIAGNOSIS
POSSIBLE CAUSES
Accidental activation or Failure of
open/close command switch
Failure of latch assembly
Failure of Power Liftgate or Body
Control module
Not in Park/Neutral or false
indication
Battery voltage too low
POWER LIFTGATE SYSTEM 8Ns - 3
is made, the module will relearn the effort and/or
time required to open or close the liftgate. This learn
cycle can be performed with a Diagnostic Scan Tool,
such as the DRB III or with a complete cycle of the
liftgate, using either one of the command switches.
Refer to Standard Procedures in this section for
detailed instructions.
DIAGNOSIS AND TESTING - POWER LIFTGATE
SYSTEM
The power liftgate system is a complex system con-
taining many components involving at least two elec-
tronic control modules. In order to perform conclusive
testing, the Programmable Communications Interface
PCI data bus circuit and the electronic modules that
provide inputs to, or receive outputs from the power
liftgate control module must be checked.
The most reliable, efficient, and accurate means to
diagnose the power liftgate system requires the use
of a DRB III scan tool and the proper Body Diag-
nostic Information. The DRB III
observe current switch status recorded in the power
liftgate control module to help the technician diag-
nose a defective switch. The DRB III
used to actuate various 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
power liftgate system inhibitors read and understood
(Refer to power liftgate system description for list).
Following are quick reference diagnostic tables to
help when diagnosing and testing the power liftgate
system.
Check for shorted or defective switch
Check wiring connections
Check for trouble codes, replace latch if
necessary
Disconnect then reconnect battery to reset
module, function liftgate, if no function
exists check for loose wire connections,
see Body Diagnostic Information for
detailed procedures
Check switch status with DRB III scan tool
Check for proper battery/ system voltage
can be used to
can also be
CORRECTION
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