B1422

CIRCUIT DESCRIPTION
The Body Control Module (BCM) monitors the Ignition 0, Ignition 1, Crank and Accessory circuits from the ignition switch. The BCM uses the voltage state (B+ or 0) and the sequence of state changes to determine the power mode called for by the ignition switch. Refer to the table in Body Control Module System Description and Operation.

CONDITIONS FOR RUNNING THE DTC
The BCM must be powered and must detect a change in the ignition switch circuit states.

CONDITIONS FOR SETTING THE DTC
^ The BCM detects an improper voltage on one of the ignition switch circuits.
^ One of the ignition switch circuits may be shorted to either B+ or ground.
^ The sequence of the change of the circuit may be incorrect for the expected power mode.

ACTION TAKEN WHEN THE DTC SETS
^ The BCM stores the DTC to memory.
^ The BCM operates in a fail-safe power mode dependent on the last valid power mode detected and the state of the engine run flag data on the class 2 serial data communications circuits.
^ The other modules on the vehicle operate in a fail safe power mode dependent on the last valid power mode transmitted by the BCM and the state of the engine run flag on the class 2 serial data communications circuits.

CONDITIONS FOR CLEARING THE DTC
^ The current DTC will clear when the BCM detects a sequence of ignition switch inputs that match the expected power mode.
^ A history DTC will clear after 100 ignition cycles with no repeated malfunction

TEST

Steps 1-4:

Steps 5-13:

Steps 14-16: