AECM & Cluster CCD Bus Message Mismatch

NOTE: This code becomes active and stored as soon as the malfunction is detected.

WHEN MONITORED: Continuously with ignition on.

SET CONDITION: Air bar warning lamp status message from the instrument cluster is the opposite state than requested by the ACM.

THEORY OF OPERATION: The body control module drives all cluster readouts (gauges and lamps) except the air bag warning lamp. The ACM sends an air bag warning lamp message (on or off) to the cluster and then receives a status message from the cluster as to the state of the lamp (on or off). If the ACM receives the opposite status message than what it requested from the instrument cluster this code will set.

POSSIBLE CAUSES:
- Faulty instrument cluster
- Faulty air bag control module (ACM)

For diagnostic procedures see DIAGNOSTIC CHARTS/TEST 1A. 1A Testing System Function