Circuit/System Description

After a loss of battery power has been restored the remote control door lock receiver (RCDLR) will perform a check on the stored vehicle identification number (VIN). If the VIN is CORRECT, the RCDLR will run the VIN Timer for a programmable length of time, typically 10 minutes. The RCDLR will send a message via the serial data circuit to the instrument panel cluster (IPC) to illuminate the SECURITY indicator. After the VIN Timer has timed out, the security indicator will turn OFF. If the VIN is INCORRECT, the RCDLR will send the fuel disable password to the engine control module (ECM) via the serial data circuit. The immobilizer system considers this to be a tamper and will not allow the vehicle to start. The RCDLR will send a message via the serial data circuit to the IPC to flash the SECURITY indicator.

Substitution detection is based on correct response from the following modules:

• IPC
• Rear integration module (RIM)
• Driver door module (DDM)
• Front passenger door module (FPDM)
• Left rear door module (LRDM)
• Right rear door module (RRDM)
• Driver position module (DPM)

The modules compare their VIN to that stored in the VIN master on every ignition ON cycle and report their status to the RCDLR. The RCDLR will only check the modules status to see the 5 correct matches when a battery reconnect has been recognized within the theft deterrent module.