Serial Data Power Mode

On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). On this vehicle the PMM is the BCM. The PMM receives 2 signals from the ignition switch.

The PMM uses the following circuits to determine the correct power mode:

• Battery voltage
• Ignition 1 voltage
• Ignition 3 voltage

When the ignition is turned to the OFF position, the vehicle enters retained accessory power (RAP) mode. RAP power mode enables selected vehicle functions to be operated for 20 minutes. Selected customer convenience devices will operate. Refer to Retained Accessory Power (RAP) Description and Operation in retained accessory for a detailed description and operation.