Chrysler Pacifica. Manual - part 515

opening and closing power liftgate. The power lift-
gate system is a complex system consisting of many
components. Refer to the following list for component
reference:

Drive Unit Components

• Liftgate Motor

• Clutch

• Channel, Bracket, Rack and Yoke Assembly

• Full Open Switch

• Optical Sensor

• Link Rod

Power Liftgate System Components

• Power Latch and Actuator

• Liftgate Power Module

• Pinch Sensor

• Overhead Console and Key Fob Command

Switches

• Chime/Thermistor Assembly
The power liftgate system utilizes its own liftgate

control module. This power liftgate module contains
all the solid state hardware and software used to
control the power liftgate system. For specific compo-
nent information refer to the individual component
descriptions later in this section.

Safety is of the utmost concern with the power lift-

gate system. Software technology has enabled the
power liftgate module to detect resistance to liftgate
travel. This allows the power liftgate module to con-
trol liftgate direction anytime an obstruction is
detected. The power liftgate can be operated manu-
ally using the liftgate outside handle switch.

The power liftgate module communicates on the

Programmable Communication Interface (PCI) Bus
Circuit. Therefore, the power liftgate module can
generate and store its own Diagnostic Trouble Codes
(DTC’s). The Body Control Module (BCM) sends and
receives messages to the power liftgate control mod-
ule via the PCI bus circuit. A diagnostic scan tool,
such as the DRB III

t is used to read and trouble-

shoot these Diagnostic Trouble Codes. Refer to the
Body Diagnostic Information for a list of diagnostic
procedures.

For a complete wiring schematic of the power lift-

gate system, refer to the Wiring section of this man-
ual. For system operation instructions refer to the
vehicles owner manual. Refer to the Body Section of
this manual for additional information on liftgate
components such as the prop rods, hinges, door align-
ment and striker alignment.

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 inhibitors
noted below:

POWER LIFTGATE SYSTEM INHIBITORS

• The Power Liftgate module will inhibit operation

of the power liftgate in extreme temperatures. These
temperatures will be approximately -22° F (-33° C)
and 149° F (65° C). A chime/thermister assembly in
the rear light bar assembly monitors the outside tem-
perature.

• The vehicle’s transmission must be in park or

neutral for the power liftgate to operate.

• The vehicle’s speed must be zero for the power

liftgate to operate.

• The vehicle’s electrical system voltage must be

within specification for the power liftgate system to
operate. A low-voltage cut-off is built into the power
liftgate system to prevent the vehicle’s battery from
discharging to the point were the vehicle cannot be
operated.

• If the vehicle’s ignition switch is in the “START”

position, the power liftgate will pause.

• If multiple obstacles are detected during the

same power open or close cycle, the liftgate will tem-
porarily go into full manual operation.

• If severe Diagnostic Trouble Codes (DTC’s) are

stored in the power liftgate control module the sys-
tem may not operate.

POWER LIFTGATE SYSTEM 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

PINCH

SENSORS.

EXTREME CAUTION 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). PERSONAL INJURY MAY RESULT.

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.

8N - 2

POWER LIFTGATE SYSTEM

WARNING: NEVER STICK OBJECTS IN THE POWER
LIFTGATE WHEN CINCHING CLOSED. YOU COULD
DAMAGE THE POWER LIFTGATE SYSTEM AND/OR
COMPONENTS

AND/OR

CAUSE

PERSONAL

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

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

t 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

t scan tool and the proper Body Diag-

nostic Information. The DRB III

t can be used to

observe current switch status recorded in the power
liftgate control module to help the technician diag-
nose a defective switch. The DRB III

t can also be

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.

LIFTGATE SYSTEM DIAGNOSIS

CONDITION

POSSIBLE CAUSES

CORRECTION

Liftgate opens unexpectedly

Accidental activation or Failure of
open/close command switch

Check for shorted or defective switch

Failure of latch assembly

Check wiring connections

Check for trouble codes, replace latch if
necessary

Failure of Power Liftgate or Body
Control module

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

Liftgate will not open/close
automatically

Not in Park/Neutral or false
indication

Check switch status with DRB III scan tool

Battery voltage too low

Check for proper battery/ system voltage

POWER LIFTGATE SYSTEM

8N - 3

POWER LIFTGATE SYSTEM (Continued)

CONDITION

POSSIBLE CAUSES

CORRECTION

Blown fuse

Check for blown fuse

Gas prop rod failure

Check condition of liftgate prop rods

BCM, NGC, or power liftgate module
critical fault codes

Check code status with DRB III scan tool

Failure of latch assembly

Check wire connections and for blown fuse

Cycle latch with DRB III and Check for
foreign matter preventing the operation of
latch assembly

Troubleshoot using Body Diagnostic
Information Replace latch assembly, if
necessary

Extreme Temperatures

No repair, Refer to power liftgate system
inhibitors

Vehicle speed greater than zero

Test for proper operation with vehicle
stopped.

Pinch Sensor activated or open
circuit

Check pinch sensor status with Scan Tool.

Wiring problems (system or vehicle)

Troubleshoot using electrical schematics.
Refer to wiring diagrams

Power loss during Liftgate
operation

Wiring problems (system or vehicle)

Troubleshoot using electrical schematics.
Refer to wiring diagrams

Low battery voltage

Charge battery

Failure of Power Liftgate or Body
Control Module

Check for diagnostic trouble codes with
DRB III.

Failure of motor assembly

Test motor assembly

No automatic latching in
primary and/or secondary
positions

Failure of latch assembly

Check wire connections and for blown fuse

Check for diagnostic trouble codes and
cycle with DRB III

Troubleshoot using Body Diagnostic
Information. 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 Module

Check for diagnostic trouble codes with
DRB III

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

Pinch Sensor activated or open/short
circuit

Check pinch sensor status with Scan Tool.

Foreign material in latch

Check and clean latch

Blown Fuse

Check fuse and replace if required

Latch will not release from
primary position

Not in Park/Neutral, vehicle speed
greater than zero or false indication

Check switch status with DRB III

8N - 4

POWER LIFTGATE SYSTEM

POWER LIFTGATE SYSTEM (Continued)

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