Grand Cherokee 2WD L6-4.0L VIN S (1997)
Power Door Lock Control Module: Description and Operation
SYSTEM OPERATION
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 communicate with each other, and with other vehicle modules 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 harness 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 feature capabilities.
The DDM circuitry controls the output to the driver front door power lock motor. The PDM circuitry 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 module on the CCD data bus to activate the output to the remaining power lock motor(s).
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:
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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 headlamps are on with the driver door open. However, the locks can still be operated manually with a key or energized with the RKE
transmitter.
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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 feature of the power lock system. This feature
can be enabled or disabled using the DRB scan tool and the proper Computers and Control Systems/Body Control Module/Testing and
Inspection Procedures.
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An RKE system panic mode, on models so equipped. If the Panic button on the RKE 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 cancel the panic mode.
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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 Computers and Control Systems/Body Control Module/Testing and Inspection
Procedures.
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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 Computers and Control
Systems/Body Control Module/Testing and Inspection Procedures.
For diagnosis of the DDM, PDM, or the CCD data bus network, refer to the proper Computers and Control Systems/Body Control Module/Testing
and Inspection Procedures.
