Serial Data Power Mode Master
WARNING: This page is about a different car, the 2004 Saturn Ion Red Line, 2004 Saturn Ion 3, 2004 Saturn Ion 2, and 2004 Saturn Ion 1. 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 BCM. The PMM receives 3 discrete ignition switch signals to differentiate which power mode will be sent over the Serial Data circuits. The table below illustrates the state of these inputs in correspondence to the ignition switch position:
3-Wire Ignition Switch Table
| Ignition Switch Position | Accessory | Run/Crank | Off/Run/Crank | Power Mode Transmitted |
|---|---|---|---|---|
|
IMPORTANT:
States marked with the * indicate the positive Passlock™ voltage level not vehicle positive battery voltage.
|
||||
| Off | 0 | 0 | 0 Key out. 1 Key in. | OFF/Awake or RAP |
| Start | 0 | 1 | 1* | Crank |
| Accessory | 1 | 0 | 0 | Accessory |
| Run | 1 | 1 | 1 | Run |