Network Message Chart - Conventional Ignition Switch
Module Network Input Messages - Body Control Module (BCM)
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Power pack status | PCM | Provides the BCM with the current ignition status of the PCM. |
OFF
When the ignition switch is turned to the OFF position, the BCM communicates the state of the ignition to the other modules by sending an "ignition status" message over the Medium Speed Controller Area Network (MS-CAN).
ACC
When the BCM receives the ACC voltage input from the ignition switch, the BCM communicates the state of the ignition to the other modules by sending an "ignition status" message over the Medium Speed Controller Area Network (MS-CAN) and a "power mode" message over the High Speed Controller Area Network (HS-CAN).
ON
When the BCM receives the ON voltage input from the ignition switch, it activates the ignition and accessory relays, providing ignition power to various vehicle systems and modules. The BCM communicates the state of the ignition to the other modules by sending an "ignition status" message over the Medium Speed Controller Area Network (MS-CAN) and a "power mode" message over the High Speed Controller Area Network (HS-CAN).
START
When the BCM receives the ON voltage input from the ignition switch (also present in the START position), it activates the ignition relay, providing ignition power to various vehicle systems and modules. The PCM communicates the state of the engine by sending an "engine state" and "power pack status" message over the High Speed Controller Area Network (HS-CAN) to the BCM. While the engine is cranking, the BCM inhibits the accessory relay. The BCM communicates the state of the ignition to the other modules by sending an "ignition status" message over the Medium Speed Controller Area Network (MS-CAN).