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 tothe power liftgate control module via the PCI bus cir-
cuit. A diagnostic scan tool, such as the DRB IIItis
used to read and troubleshoot these Diagnostic Trou-
ble Codes (DTC). Refer to the Body Diagnostic Man-
ual for a complete list of diagnostic routines.
For additional information refer to Power Liftgate
Operation. For a complete system wiring schematic
refer to Wiring Diagrams. For system operation
instructions refer to the vehicles owner manual.
Refer to the Body section of the service manual
for additional information on liftgate components
such as the prop rods, hinges, door alignment and
striker alignment.
WARNING: BE CERTAIN TO READ ALL WARNINGS
AND CAUTIONS (NOTED BELOW) IN POWER LIFT-
GATE SYSTEM OPERATION BEFORE ATTEMPTING
ANY SERVICE OF THE POWER LIFTGATE SYSTEM
OR COMPONENTS.
OPERATION
With the push of a power liftgate open/close com-
mand switch (key fob or overhead console mounted) a
signal is sent out on the J1850 PCI Data Bus circuit.
This signal is detected at the body control module
(BCM). The BCM then sends a signal out on the
J1850 PCI Data Bus circuit to the power liftgate
module. The power liftgate module then signals the
power liftgate motor to start an open or close cycle,
depending on what position the liftgate is in open or
closed.
During a liftgate open or close cycle, if the power
liftgate module detects sufficient resistance to liftgate
travel, such as an obstruction in the liftgates path,
the power liftgate control module will immediately
stop the liftgate movement and reverse travel to the
full open or closed position. The ability for the power
liftgate module to detect resistance to liftgate travel
is accomplished by hall effect sensors, drive motor
speed and pinch sensors (tape switches).
The power liftgate control module has the ability to
learn. Anytime the liftgate is opened or closed using
the power liftgate system the module learns from its
cycle. If a replacement power liftgate component is
installed or a liftgate adjustment is made, the mod-
ule will relearn the effort and/or time required to
open or close the door. This learn cycle can be per-
formed with a Diagnostic Scan Tool, such as the DRB
IIItor with a complete cycle of the liftgate, using
any one of the command switches. Refer to Standard
Procedures in this section for detailed instructions.
The power liftgate system is designed with a num-
ber of system inhibitors. These inhibitors are neces-
sary for safety and / or feasibility of the power
liftgate system. Refer to power liftgate system inhib-
itors noted below:Fig. 2 KEY FOB
1 - LEFT SLIDING DOOR SWITCH
2 - RIGHT SLIDING DOOR SWITCH
3 - LIFTGATE SWITCH
Fig. 3 LIFTGATE FUSE LOCATION
RSPOWER LIFTGATE SYSTEM8N-3
POWER LIFTGATE SYSTEM (Continued)
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)
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)
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)
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)
Safety is of the utmost concern with the power
sliding door system. Software technology has enabled
the power sliding door control module to detect resis-
tance to door travel. This allows the power sliding
door to stop and reverse direction any time an
obstruction is felt or any of the command switches
are operated (while closing only). Battery voltage is
supplied to the power sliding door system through a
40 amp fuse, located in the Intelligent Power Module
(IPM) assembly (Fig. 3). The child lockout switch pre-
vents children from opening or actuating the power
sliding door system when desired. In the unlikely
event that the power sliding door system develops a
fault, the power sliding door can still be operated
manually from the interior or exterior door handle,
just like a standard manual sliding door.
The power sliding door control module communi-
cates on the J1850 PCI Data Bus Circuit. Therefore,
the power sliding door control module can generate
and store its own diagnostic trouble codes (DTC). A
diagnostic scan tool, such as the DRB IIItis used to
read and diagnose these trouble codes. Refer to the
Body Diagnostic Manual for a complete list of diag-
nostic routines.
Fig. 1 POWER SLIDING DOOR INTRODUCTION
Fig. 2 KEY FOB
1 - LEFT SLIDING DOOR SWITCH
2 - RIGHT SLIDING DOOR SWITCH
3 - LIFTGATE SWITCH
8N - 20 POWER SLIDING DOOR SYSTEMRS
POWER SLIDING DOOR SYSTEM (Continued)
NOTE: It may be possible to generate Sliding Door
Diagnostic Trouble Codes during normal power
sliding door operation. Refer to the Body Diagnos-
tic Manual for a complete list of diagnostic routines.
For additional information, (Refer to 8 - ELECTRI-
CAL/POWER DOORS - OPERATION) . For a com-
plete power sliding door system wiring schematic,
refer to Wiring Diagrams. For power sliding door sys-
tem operation instructions, refer to the vehicle owner
manual.
WARNING: BE CERTAIN TO READ ALL WARNINGS
AND CAUTIONS IN POWER SLIDING DOOR OPER-
ATION BEFORE ATTEMPTING ANY SERVICE OF
POWER SLIDING DOOR SYSTEM OR COMPO-
NENTS.
OPERATION
With the push of a power sliding door open/close
command switch (key fob, overhead console or B-pil-
lar mounted) a signal is sent out to the Body Control
Module (BCM). The BCM then sends a signal out on
the PCI Data Bus circuit (J1850) to the power sliding
door module. The power sliding door module then
signals the power sliding door latch to release the
door to the unlatched and movable position. The
motor then starts an open cycle.
During the door open cycle, if the power sliding
door module detects sufficient resistance to door
travel, such as an obstruction in the door's path, the
power sliding door module will immediately stop door
movement and reverse door travel to the full open orclosed position. The ability for the power sliding door
module to detect resistance to door travel is accom-
plished by hall effect sensors and the door motor
speed.
The power sliding door control module has the abil-
ity to learn. Anytime a door is opened or closed using
the power sliding door system the module learns
from its cycle. If a replacement power sliding door
component is installed or a door adjustment is made,
the module must re-learn the effort required to open
or close the door. A learn cycle can be performed with
a Diagnostic Scan Tool, such as the DRB IIIt, or with
a complete cycle of the door, using any one of the
command switches. Refer to Standard Procedures in
this section for detailed instructions.
The power sliding door system is designed with a
number of system inhibitors. These inhibitors are
necessary for safety and/or feasibility of the power
sliding door system. See the power sliding door sys-
tem inhibitors noted below:
POWER SLIDING DOOR SYSTEM INHIBITORS
²The power sliding door must be in thefullopen
or closed position in order for the power sliding door
system to start a cycle. If the door is not in this posi-
tion (based on the input from the full open, pawl or
ratchet switches) the door control module will not
respond to command switch inputs.
²The vehicles transmission must be inpark or
neutralin order for the power sliding door system to
start a cycle.
²The vehicles child lockout switch must be in the
ªUNLOCKEDº position in order for the power sliding
door systems B-pillar switches to function.
²If multiple obstacles are detected during the
same power open or close cycle the power sliding
door may go into full manual mode.
²If severe Diagnostic Trouble Codes (DTC) are
stored in the power sliding door control module the
power sliding door may go into full manual mode.
²Due to the high pressure created in the passen-
ger compartment with the blower motor on high, the
power sliding door may not complete a power close
cycle unless a window is cracked, allowing the pres-
sure to escape. This situation will only be experi-
enced on some vehicles, or vehicles with brand new
side door weather seals installed. Refer to the Side
Door Adjustment procedure in the Standard Proce-
dures section of this group.
²The vehicles fuel tank filler door must be in the
closed position. Due to the sliding door interference
with the open fuel tank filler door, mechanical link-
age prevents the side door from opening and striking
the fuel door. Refer to the Body section of this man-
ual for detailed information on the fuel door lockout
feature.Fig. 3 POWER SIDE DOOR FUSE LOCATION
RSPOWER SLIDING DOOR SYSTEM8N-21
POWER SLIDING DOOR SYSTEM (Continued)
POWER SLIDING DOOR SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
Door opens unexpectedly Failure of sliding door control or
body control moduleDisconnect then reconnect battery to reset
module, function door, if no function exists
check for loose wire connections, Refer to
the Body Diagnostic Manual for detailed
procedures
Failure of latch assembly Check wiring/cable connections and for
blown fuse
Check for trouble codes, replace latch if
necessary
Failure of open/close command
switchCheck for shorted or defective switch
Failure of striker Striker misaligned or loose
Striker damaged
Replace striker if necessary
Door will not open manually
using inside handleFailure of inside handle assembly Check for broken inside handle assembly
Check cable connections at latch and
handle assembly.
Check for binds or kinks in cable.
Check for foreign matter preventing the
operation of handle assembly
Replace the handle if necessary
Failure of latch assembly Check cable connections
Check for foreign matter preventing the
operation of latch assembly
Replace latch if necessary
Failure of inside handle cable
assemblyCheck cable for binding
Check cable for broken condition
Replace the cable, if necessary
Binding or sticking of components Check for foreign matter preventing the
operation of door
Establish location of binding
Replace necessary components
Door will not open manually
using outside handleFailure of outside handle assembly Check for broken outside handle assembly
Check cable connections at latch and
handle assembly.
Check for binds or kinks in cable.
Check for foreign matter preventing the
operation of handle assembly
RSPOWER SLIDING DOOR SYSTEM8N-23
POWER SLIDING DOOR SYSTEM (Continued)