Body Control Module; Circuit Breaker; Door Module; Power Lock Motor - Jeep 1997 Grand Cherokee Service Manual

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DESCRIPTION AND OPERATION (Continued)
Some of the features and functions of the power
lock and Remote Keyless Entry (RKE) systems made
possible because of the communication of the door
modules on the CCD data bus network include:
• A door-lock inhibit feature which prevents the
power lock system from being energized with a door
switch if the key is in the ignition and/or the head-
lamps are on with the driver door open. However, the
locks can still be operated manually with a key or
energized with the RKE transmitter.
• A rolling door locks feature will automatically
lock all of the doors and the liftgate, after the vehicle
reaches a speed of about 24 kilometers-per-hour (15
miles-per-hour) or greater. This feature will also lock
the doors if a door is opened, then closed again at
any speed above 24 kilometers-per-hour (15 miles-
per-hour). Rolling door locks is a programmable fea-
ture of the power lock system. This feature can be
enabled or disabled using the DRB scan tool and the
proper Body Diagnostic Procedures manual.
• An RKE system panic mode, on models so
equipped. If the Panic button on the RKE transmit-
ter is depressed, the horn will sound and lights will
flash on the vehicle for about three minutes, or until
any of the three transmitter buttons is depressed. A
vehicle speed of about 24 kilometers-per-hour (15
miles-per-hour) will also cancel the panic mode.
• A programmable feature of the RKE system is
the enabling or disabling of the horn chirp following
the RKE Lock function. This feature can be enabled
or disabled using the DRB scan tool and the proper
Body Diagnostic Procedures manual.
• Another programmable feature is the enabling
or disabling of the RKE system unlocking the driver
door only, or all doors upon one depression of the
transmitter Unlock button. This feature can be
enabled or disabled using the DRB scan tool and the
proper Body Diagnostic Procedures manual.
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.
POWER LOCK SYSTEMS
One of the functions and features that the BCM
supports and controls on models so equipped, is the
Remote Keyless Entry (RKE) Panic Mode. The BCM
receives input from the RKE receiver in the Passen-
ger Door Module (PDM) on the CCD data bus. The
programming in the BCM allows it to process the
information from this input and send control outputs
to the headlamp relay, horn relay, and park lamp
relay to accomplish the panic mode functions.
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 LOCK MOTOR

In the power lock and Remote Keyless Entry
(RKE) systems, the locks are actuated by a reversible
motor mounted within each door and the liftgate.
The driver front door lock motor direction is con-
trolled by the battery and ground feeds from the
Driver Door Module (DDM). The remaining door lock
motors and the liftgate lock motor are controlled by
the battery and ground feeds from the Passenger
Door Module (PDM).
The power lock motor cannot be repaired and, if
faulty or damaged, the entire motor must be
replaced.

CIRCUIT BREAKER

An automatic resetting circuit breaker in the junc-
tion block is used to protect the power lock system
circuit. The circuit breaker can protect the system
from a short circuit, or from an overload condition
caused by an obstructed or stuck lock motor, latch, or
lock linkage.
The circuit breaker cannot be repaired and, if
faulty, it must be replaced.
REMOTE KEYLESS ENTRY TRANSMITTER
The Remote Keyless Entry (RKE) system transmit-
ter is equipped with up to three buttons, labeled
Lock, Unlock, and an optional Panic button. It is also
equipped with a key ring and is designed to serve as
a key fob. The operating range of the transmitter
radio signal is up to 7 meters (23 feet) from the RKE
receiver.
Each transmitter has a different vehicle access
code, which must be programmed into the memory of
the RKE receiver in the vehicle in order to operate
armature and below
8P - 3
the