Fail-safe Operation
The remote control door lock receiver (RCDLR) is the back up power mode master (BPMM). The both BCM and RCDLR receive signals from the ignition mode switch, representing the mode switch data, through 2 different circuits. Therefore if BPMM becomes enabled, it can determine and transmit all the system power modes per the lists above, except RAP. There is no degradation in system operation if the BPMM is the RCDLR. Since the operation of the vehicle systems depends on the power mode, there is a fail-safe plan in place if the power mode message is not received from the BCM or RCDLR. The fail-safe plan covers modules with discrete ignition signal inputs as well as those modules using exclusively serial data control of power mode. The engine control module (ECM) behaves differently.