Serial Data Power Mode
WARNING: This page is about a different car, the 2004 Pontiac Grand Am and 2004 Oldsmobile Alero. However, it is still accessible from the selected car via links, so may be relevant.
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