Serial Data Power Mode
On vehicles that have several control modules connected by serial data circuits, one module is the power mode master (PMM). The BCM is the PMM on this vehicle. The PMM receives 3 discrete ignition switch signals to differentiate which power mode will be sent over the class 2 serial data circuit.
To determine the correct power mode the PMM uses the following circuits:
- Ignition 0
- Ignition 1
- Ignition 3