Serial Data Power Mode
WARNING: This page is about a different car, the 2002 Cadillac Seville. 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). On this vehicle the PMM is the DIM. The PMM receives 4 signals from the ignition switch.
To determine the correct power mode the PMM uses the following circuits:
- Accessory voltage
- Crank voltage
- Ignition 1 voltage
- Off/Run/Crank voltage