Power Window System; Description And Operation; Body Control Module; Door Module - Jeep 1997 Grand Cherokee Service Manual

8S - 2 POWER WINDOW SYSTEMS
DESCRIPTION AND OPERATION (Continued)
Each power window switch, except the lockout
switch, is illuminated by a Light-Emitting Diode
(LED) when the ignition switch is turned to the On
position. However, when the lockout switch is placed
in the Lock position, the LED for the locked-out front
and rear passenger door power window switches is
turned off.
The front door power window switches and the
power window lockout switch are integral to the
Driver Door Module (DDM) or Passenger Door Mod-
ule (PDM), respectively.
switches provide an up or down (or lock and unlock
signal in the case of the lockout switch) to the door
module circuitry.
The DDM circuitry controls the output to the
driver side front and rear door power window motors,
and supplies electrical current as required for opera-
tion of the driver side rear door power window
switch. The PDM circuitry controls the output to the
passenger side front and rear door power window
motors, and supplies electrical current as required
for operation of the passenger side rear door power
window switch. When a DDM-integrated power win-
dow switch for a passenger side window is actuated,
the DDM circuitry sends a message to the PDM on
the Chrysler Collision Detection (CCD) data bus to
activate the output to that power window motor(s).
The front door power window switches and their
lamps cannot be repaired so, if faulty or damaged,
the entire door module must be replaced. The rear
door power window switches and their lamps cannot
be repaired but, if faulty or damaged, only the
affected switch unit must be replaced.

DOOR MODULE

A Driver Door Module (DDM) and a Passenger
Door Module (PDM) are used on this model to control
and integrate many of the electronic features and
functions on the vehicle. The DDM and PDM commu-
nicate with each other, and with other vehicle mod-
ules on the Chrysler Collision Detection (CCD) data
bus network.
The CCD data bus network allows the sharing of
sensor information. This helps to reduce wire har-
ness complexity, internal controller hardware, and
component sensor current loads. At the same time,
this system provides increased reliability, enhanced
diagnostics, and allows the addition of many new fea-
ture capabilities.
The DDM circuitry controls the output to the
driver side front and rear door power windows. The
PDM circuitry controls the output to the passenger
side front and rear door power windows. The DDM
can control the PDM output by sending control mes-
sages to the PDM over the CCD data bus.
These power window
Some of the features and functions of the power
window system made possible because of the commu-
nication of the door modules on the CCD data bus
network include:
• Power window operation after ignition off fea-
ture.
• Power window lockout function.
• Power window switch LED illumination control
function.
For diagnosis of the DDM, PDM, or the CCD data
bus network, refer to the proper Body Diagnostic
Procedures manual.

BODY CONTROL MODULE

A Body Control Module (BCM) is used on this
model to control and integrate many of the electronic
functions and features included on the vehicle. The
BCM contains a central processing unit and inter-
faces with other modules in the vehicle on the
Chrysler Collision Detection (CCD) data bus network.
The CCD data bus network allows the sharing of
sensor information. This helps to reduce wire har-
ness complexity, reduce internal controller hardware,
and reduce component sensor current loads. At the
same time, this system provides increased reliability,
enhanced diagnostics, and allows the addition of
many new feature capabilities.
One of the functions and features that the BCM
supports and controls, is the power window system.
The BCM receives inputs from the ignition switch
and the door ajar switches. The programming in the
BCM allows it to process the information from these
inputs and send ignition switch and door ajar status
messages to the DDM and PDM on the CCD data
bus. The DDM and PDM use this information to con-
trol the lighting of the power window switch lamps,
and to control the operation of the power window
after ignition off feature.
The BCM is mounted under the driver side out-
board end of the instrument panel, behind the instru-
ment panel support
outboard switch pod. Refer to Group 8E - Instrument
Panel Systems for the removal and installation pro-
cedures. For diagnosis of the BCM or the CCD data
bus, refer to the proper Body Diagnostic Procedures
manual. The BCM can only be serviced by an autho-
rized electronic repair station. Refer to the latest
Warranty Policies and Procedures manual for a cur-
rent listing of authorized electronic repair stations.

POWER WINDOW MOTOR

A permanent magnet reversible motor moves the
window regulator through an integral gearbox mech-
anism. A positive and negative battery connection to
the two motor terminals will cause the motor to
rotate in one direction. Reversing the current
armature and below
ZG
the