Remote Keyless Entry Receiver; Diagnosis And Testing; Circuit Breaker; Door Module - Jeep 1997 Grand Cherokee Service Manual

8P - 4 POWER LOCK SYSTEMS
DESCRIPTION AND OPERATION (Continued)
the RKE system. In addition, vehicles with the
optional memory system must have their access
codes programmed in the RKE receiver so that the
molded-in numbers "1" or "2" on the back of the
transmitter case coincide with the memory "1" and
"2" buttons of the memory set switch in the vehicle.
Transmitter programming must be performed with
a DRB scan tool. Refer to the proper Body Diagnostic
Procedures manual for the transmitter programming
procedure.
The transmitter operates on two Duracell DL2016
(or equivalent) batteries. Typical battery life is from
one to two years. The transmitter cannot be repaired
and, if faulty or damaged, it must be replaced.

REMOTE KEYLESS ENTRY RECEIVER

The Remote Keyless Entry (RKE) receiver is a
radio frequency unit contained in the Passenger Door
Module (PDM). The PDM also contains the program
circuitry for the RKE system. The PDM is located
inside the passenger side front door, and is secured
to the door trim panel.
The RKE receiver is energized by one of up to
three messages from the RKE transmitter; Unlock,
Lock, or an optional Panic. The PDM circuitry
responds to these messages to lock or unlock the
power lock motors that it controls. The PDM circuitry
also puts Lock, Unlock, and the optional Panic mes-
sages on the Chrysler Collision Detection (CCD) data
bus.
These messages will result in the Driver Door
Module (DDM) locking or unlocking the driver side
front door, and/or the Body Control Module (BCM)
initiating the proper Horn Chirp, Illuminated Entry,
and Vehicle Theft Alarm functions. If the vehicle is
equipped with the optional memory system, the
proper CCD Unlock message will also result in the
DDM initiating its memory recall functions.
For diagnosis of the RKE receiver, the PDM, the
DDM, or the CCD data bus, refer to the proper Body
Diagnostic Procedures manual. The RKE receiver is
only serviced as a unit with the PDM and, if faulty
or damaged, the PDM unit must be replaced.

DIAGNOSIS AND TESTING

POWER LOCK AND REMOTE KEYLESS ENTRY
SYSTEM
As a preliminary diagnosis for the power lock and
remote keyless entry systems, note the system oper-
ation while you actuate both the Lock and Unlock
functions with the power lock switches and the
remote keyless entry transmitter. Then, proceed as
follows:
• If the system fails to function with either the
switches or the transmitter, see the Circuit Breaker
diagnosis in this group.
• If the system functions with both switches, but
not with the transmitter, see the Remote Keyless
Entry Transmitter diagnosis in this group.
• If the system functions with the transmitter, but
not with one or both switches, see the Door Module
diagnosis in this group.
• If one lock motor fails to operate with the
switches or the transmitter, see the Power Lock
Motor diagnosis in this group.

CIRCUIT BREAKER

For circuit descriptions and diagrams, refer to
8W-61 - Power Door Locks in Group 8W - Wiring
Diagrams.
(1) Locate the correct circuit breaker in the junc-
tion block. Pull out the circuit breaker slightly, but
be sure that the terminals still contact the terminals
in the junction block.
(2) Connect the negative lead of a 12-volt DC volt-
meter to a good ground.
(3) With the voltmeter positive lead, check both
terminals of the circuit breaker for battery voltage.
If only one terminal has battery voltage, the circuit
breaker is faulty and must be replaced. If neither ter-
minal has battery voltage, repair the open circuit
from the Power Distribution Center (PDC) as
required. If the circuit breaker checks OK, but no
power locks operate, see the diagnosis for the Door
Module in this group.

DOOR MODULE

NOTE: The following tests may not prove conclu-
sive in the diagnosis of this component. The most
reliable, efficient, and accurate means to diagnose
this system involves the use of a DRB scan tool
and the proper Body Diagnostic Procedures man-
ual.
Remember, the DDM circuitry controls the output
to the driver side front door power lock motor. The
PDM circuitry controls the output to the power lock
motors for the remaining doors and the liftgate. For
circuit descriptions and diagrams, refer to 8W-61 -
Power Door Locks in Group 8W - Wiring Diagrams.
(1) Disconnect and isolate the battery negative
cable. Remove the front door trim panel as described
in this group. Go to Step 2.
(2) Check the 12-way door module wire harness
connector to see that it is fully seated in the door
module receptacle. If OK, go to Step 3. If not OK,
install the wire harness connector properly.
(3) Unplug the 12-way door module wire harness
connector from the door module. Check for continuity
ZG