Circuit Description

When SDM recognizes ignition voltage applied to SDM terminal No. 12 (Black/Red wire) is greater than 9 volts, AIR BAG warning light is flashed 7 times to verify operation. At this time, SDM performs turn-on tests followed by continuous monitoring test. When malfunction is detected, SDM sets a current Diagnostic Trouble Code (DTC) and illuminates AIR BAG warning light. SDM will clear current DTC's and move them to a history file when malfunction is no longer detected and/or ignition is cycled, except for DTC's 51, 53 and 71. DTC 71 can only be cleared using a scan tool CLEAR CODES command, if DTC 51 and 53 DO NOT exist. If DTC's 51, 53 and 71 exist, codes cannot be cleared using a CLEAR CODES command.