Circuit Description

The air bag sensing and diagnostic module (SDM) sends serial data along the tertiary serial data bus, circuit 774, to the body control module (BCM) and then on to the instrument cluster on the secondary serial data bus, circuit 1061. This is read by the instrument cluster, which displays the status of the SDM on the multifunction display (MFD) and cluster indicator. DTC 12 will set if there is no SDM data message on the bus for more than 10 seconds. The DTC is reset within 10 seconds of the arrival of a SDM data message on the bus. The DTC is logged as a History DTC.