Operation-Remote Keyless Entry System

WARNING: This page is about a different car, the 2004 Dodge Dakota and 2003 Dodge Dakota. However, it is still accessible from the selected car via links, so may be relevant.

On vehicles with the Remote Keyless Entry (RKE) system, the power locks can be operated remotely using the RKE transmitter. If the vehicle is so equipped, the RKE transmitter also arms and disarms the factory-installed Vehicle Theft Security System (VTSS). Three small, recessed buttons on the outside of the transmitter case labelled Lock, Unlock, and Panic allow the user to choose the function that is desired. The RKE transmitter then sends the appropriate Radio Frequency (RF) signal. An RF receiver that is integral to the Central Timer Module (CTM) receives the transmitted signal, which then uses its internal electronic programming to determine whether the received signal is valid and what function has been requested. If the signal is valid, the CTM then provides the programmed features.

Besides operating the power lock system and arming or disarming the VTSS, the RKE system also controls the following features:

Driver Door Unlock Only -If this feature is enabled, the CTM unlocks only the driver side front door upon receipt of a first valid Unlock signal through a separate internal relay and control outputs to the driver side front door power lock motor. Then upon receipt of a second valid Unlock signal, the CTM unlocks all of the remaining doors through a separate internal relay and control circuits for those power lock motors.
Horn Chirp -If this feature is enabled, the CTM provides a horn chirp by internally pulling the control coil of the horn relay to ground through a hard wired circuit output.
Illuminated Entry -The CTM provides illuminated entry by internally controlling the current flow to the courtesy lamps and cargo lamp in the vehicle through a hard wired output circuit.
Optical Chirp -If this feature is enabled, the CTM provides flashes of the park lamps by internally pulling the control coil of the park lamp relay to ground through a hard wired circuit output.
Panic Mode -The CTM provides the horn pulse by internally pulling the control coil of the horn relay through a hard wired circuit output, then flashes the headlamps and illuminates the courtesy lamps through its internal high side control of these circuits. The CTM also monitors the vehicle speed through electronic messages it receives from the Powertrain Control Module (PCM) over the Programmable Communications Interface (PCI) data bus network.

The RKE system operates on battery current received through a fused B(+) circuit from a fuse in the Junction Block (JB) so that the system remains functional, regardless of the ignition switch position. The RKE system can retain the vehicle access codes of up to four RKE transmitters. The transmitter codes are retained in RKE system memory, even if the battery is disconnected. If a transmitter is faulty or is lost, new transmitter vehicle access codes can be programmed into the system using a DRBIII(R) scan tool. Refer to the appropriate diagnostic information. Many of the electronic features in the vehicle controlled or supported by the CTM are programmable using the DRBIII(R) scan tool. If any of the CTM hardware components are damaged or faulty, the entire CTM unit must be replaced. The hard wired inputs or outputs of the CTM can be diagnosed using conventional diagnostic tools and methods; however, for diagnosis of the CTM or the PCI data bus, the use of a DRBIII(R) scan tool is required. Refer to the appropriate diagnostic information.