Jeep Cherokee (XJ): Description and operation

Power lock switch

The power locks are controlled by a two-way switch that is integral to the Driver Door Module (DDM) and the Passenger Door Module (PDM) mounted in the trim panel of its respective 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 provide a hard-wired lock or unlock signal to the power lock system control circuitry, which is located in the PDM.

The power lock switches and their lamps cannot be repaired. If the switches are damaged or faulty, the entire PDM or DDM unit must be replaced.

Door module

A Driver Door Module (DDM) and a Passenger Door Module (PDM) are used on all models equipped with power locks and power windows. Each door module houses both the front door power lock and power window switches. In addition to the switches for its own door, the DDM houses individual switches for each passenger door power window, a power window lockout switch and the power mirror switch. The PDM contains the control circuitry and the power lock and unlock relays for the entire power lock system.

In its role as the power lock control module, the PDM receives inputs from the battery, the ignition switch, the DDM, the driver door ajar switch, the key-in ignition switch, and the headlamp switch. It also receives a hard-wired input from the remote Keyless Entry (RKE) receiver, if the vehicle is so equipped. In response to these inputs, the PDM sends the proper outputs to control the power lock motors through its integral power lock and unlock relays.

The DDM and the PDM are mounted to their respective front door trim panels. The DDM and PDM are serviced individually and cannot be repaired. If the DDM or PDM, or any of the switches and circuitry that they contain are faulty or damaged, the complete DDM or PDM unit must be replaced.

Power lock motor

In the power lock and Remote Keyless Entry (RKE) systems, the locks are actuated by a reversible electric motor mounted within each door and the liftgate.

The power lock motor direction is controlled by the battery and ground feeds from the power lock and unlock relays integral to the Passenger Door Module (PDM).

The power lock motors cannot be repaired and, if faulty or damaged, the entire motor must be replaced.

Remote keyless entry transmitter

The Remote Keyless Entry (RKE) system transmitter is equipped with two buttons, labeled Lock and Unlock. 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 the RKE system. See Remote Keyless Entry Transmitter Programming in this group for more information.

The transmitter operates on two Panasonic CR2016 (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

On models with the Remote Keyless Entry (RKE) option, an RKE receiver is mounted in an RKE housing, or in the overhead console housing on the vehicle headliner. The RKE receiver is a radio frequency unit that also contains the RKE system program logic.

The RKE receiver also performs as a smart relay for the illuminated entry feature.

The RKE receiver has a memory function to retain the vehicle access codes of at least one, but no more than four RKE transmitters. The receiver is designed to retain the transmitter codes in memory, even if the battery is disconnected.

The RKE receiver receives inputs from the battery, the driver door ajar switch, and the Chrysler Collision Detection (CCD) data bus. It also receives the radio signal input from the RKE transmitter. In response to those inputs, it is programmed to control outputs to the power lock motors, the courtesy lamp circuits, and the vehicle horn.

The RKE system for this vehicle also features a customer programmable horn chirp feature. This feature allows the customer the option of enabling or disabling the horn chirp request that the RKE receiver issues as an audible indication that a valid Lock signal has been received from the RKE transmitter.

See Remote Keyless Entry Receiver Programming in this group for more information on this feature.

The RKE receiver cannot be repaired and, if faulty or damaged, it must be replaced.