General Information; Memory System; Power Lock System; Remote Keyless Entry System - Jeep 1997 Grand Cherokee Service Manual

8P - 2 POWER LOCK SYSTEMS
GENERAL INFORMATION (Continued)
Refer to 8W-61 - Power Door Locks in Group 8W -
Wiring Diagrams for circuit descriptions and dia-
grams. Refer to Group 23 - Body for the power lift-
glass release component service procedures.

REMOTE KEYLESS ENTRY SYSTEM

The Remote Keyless Entry (RKE) system is a radio
frequency system that allows the use of a remote
transmitter to control the power lock and illuminated
entry systems. If the vehicle is so equipped, the RKE
transmitter can also control the memory seat, mem-
ory mirror, memory radio, and the vehicle theft
alarm systems.
The RKE system consists of the remote key fob
transmitter and a receiver with program logic, which
is integral to the passenger door module. The RKE
system can retain the vehicle access codes of two
transmitters. The transmitter codes are retained in
memory, even if the battery is disconnected.
If a transmitter is faulty or lost, new transmitter
vehicle access codes can be programmed into the sys-
tem using a DRB scan tool and the proper Body
Diagnostic Procedures manual.
On models so equipped, a function of the RKE sys-
tem made possible by the connection of the passenger
door module to the Chrysler Collision Detection
(CCD) data bus network is a panic mode. If the Panic
button on the transmitter 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 can-
cel the panic mode.

MEMORY SYSTEM

An electronic memory system is an available option
on this model. The memory system is able to store
and recall the driver power seat positions (including
power lumbar and recliner positions) and both out-
side power mirror positions. For vehicles with a radio
connected to the Chrysler Collision Detection (CCD)
data bus network, the memory system is also able to
store and recall ten radio station presets (including
last station tuned) for two drivers. The memory sys-
tem will automatically return to all of these settings
when the corresponding button (Driver 1 or 2) of the
memory switch on the driver front door trim panel is
depressed, or when the doors are unlocked using the
corresponding (Driver 1 or 2) Remote Keyless Entry
(RKE) transmitter.
The Driver Door Module (DDM) receives hard-
wired input from the memory switch on the driver
front door trim panel. The DDM also receives mes-
sages on the CCD data bus from the RKE receiver in
the Passenger Door Module (PDM) for the memory
select function. The DDM processes these inputs and
sends messages to the radio (if the radio is CCD data
bus capable), the PDM, and the Memory Seat Module
(MSM) on the CCD data bus for memory recall.
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.
This group covers only the conventional diagnostic
procedures for the power lock and RKE system com-
ponents. For diagnosis of the memory system, use of
a DRB scan tool and the proper Body Diagnostic Pro-
cedures manual are recommended. For additional
information on the features and functions of the
memory system, refer to the vehicle owner's manual.

DESCRIPTION AND OPERATION

POWER LOCK SWITCH
The power locks are controlled by a two-way switch
mounted in the trim panel of each front door. Each
switch is illuminated by a light-emitting diode when
the ignition switch is turned to the On position.
The power lock switches are integral to the Driver
Door Module (DDM) or Passenger Door Module
(PDM), respectively. The power lock switch provides
a lock or unlock signal to the door module circuitry.
The power lock switches and their lamps cannot be
repaired. If the switches are damaged or faulty, the
entire door module 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 front door power lock motor. The PDM cir-
cuitry controls the output to the power lock motors
for the remaining doors and the liftgate. When a door
lock switch is actuated, the door module circuitry for
that switch sends a message to the other door mod-
ule on the CCD data bus to activate the output to the
remaining power lock motor(s).
ZG