Circuit Description
The body control module (BCM) is the power mode master responsible for sending ignition switch position information on the class 2 serial data link. There are 3 discrete wires from the ignition switch contacts monitored by the BCM in order to determine the present power mode. The BCM communicates this power mode information to all class 2 modules on the class 2 serial data link. The following table represents BCM power mode data:
Correct Power Mode Inputs
| Ignition Switch Position | BCM Input and Scan Tool Display | ||
|---|---|---|---|
| Ignition 0 | Ignition 1 | Ignition Accessory | |
| OFF and LOCK | Inactive | Inactive | Inactive |
| ACC | Active | Inactive | Active |
| ON | Active | Active | Active |
| CRANK | Active | Active | Inactive |