Circuit Description

WARNING: This page does not describe the selected car, but rather 10 other vehicles, including the 1998 GMC Yukon, 1998 GMC Suburban, 1998 GMC Pickup, 1998 GMC Cab & Chassis, and 1998 GMC C3500 HD. However, it is still accessible from the selected car via links, so may be relevant.

When the inflatable restraint Sensing and Diagnostic Module (SDM) recognizes IGNITION 1 voltage, applied to terminal?10, is greater than 8.2 volts, the SDM flashes the AIR BAG warning lamp seven times to verify operation. At this time the SDM performs POWER-ON tests followed by the RESISTANCE MEASUREMENT test and the CONTINUOUS MONITORING tests. Upon detection of a malfunction, the SDM sets a current Diagnostic Trouble Code (DTC) and illuminates the AIR BAG warning lamp. The SDM will clear current DTCs and preserve them in a history file when:

The malfunction is no longer detected
The ignition switch is cycled

This does not include DTCs B1018, B1024, B1051, B1053, and B1071. DTCs B1018, B1024, B1051, B1053 are latched codes. You cannot clear a latched code. DTC B1071 may not clear after you issue a clear codes command

IMPORTANT: Repair the malfunction that set the DTC before you replace the SDM