Grand Cherokee 2WD Limited V8-4.7L (2002)
Keyless Entry Module: Description and Operation
The Remote Keyless Entry (RKE) receiver is a radio frequency unit contained within the Passenger Door Module (PDM). The PDM also contains the
program logic circuitry for the RKE system. The PDM is secured with screws to the back of the trim panel inside the passenger side front door. The RKE
receiver has a memory function to retain the vehicle access codes of up to four RKE transmitters. The receiver is designed to retain the transmitter codes
in memory, even if the battery is disconnected.
For diagnosis of the RKE receiver, the PDM, or the Programmable Communications Interface (PCI) data bus a DRB III scan tool and the appropriate
diagnostic information are required. The RKE receiver is only serviced as a unit with the PDM and, if faulty or damaged, the entire PDM unit must be
replaced. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/DOOR MODULE - DESCRIPTION).
The RKE receiver is energized by one of three messages from the RKE transmitter: Unlock, Lock, or Panic. The PDM circuitry responds to these
messages to lock or unlock the power lock motors that it controls. The PDM circuitry also sends Lock, Unlock, and Panic messages to other electronic
modules over the Programmable Communications Interface (PCI) data bus. These messages will result in the Driver Door Module (DDM) locking or
unlocking the driver side front door, and the other electronic modules in the vehicle responding as their programming dictates.
