Chart A SDM Integrity Check

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
When the SDM recognizes "Ignition 1" voltage, applied to terminal "B9," is greater than 7 volts, the AIR BAG" waining lamp is flashed seven times to verify operation. At this time the SDM performs "Turn-ON" tests followed by "Current Source Diagnostics" and "Continuous Monitoring" tests. When a malfunction is detected the SDM sets a current diagnostic trouble code and illuminates the "AIR BAG" warning lamp. The SDM will clear current diagnostic trouble codes and move them to a history file when the malfunction is no longer detected and/or the ignition switch is cycled, except for DTCs RO51, RO52, and RO71. DTC RO51 can only be cleared using a scan tool "Clear Codes" command. DTCs RO52 and RO71 may not clear alter a "Clear Codes" command is issued.

CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test confirms a current malfunction. If no current malfunction is occurring (History DTC set) the "Diagnostic Aids" for the appropriate diagnostic trouble code should be referenced. The SDM should not be replaced for a History Diagnostic Trouble Code.
2. This test checks for a malfunction introduced into the SIR system during the diagnostic process. It is extremely unlikely that a malfunctioning SDM would cause a new malfunction to occur during the diagnostic process.
3. When all circuitry outside the SDM has been found to operate properly, as indicated by the appropriate diagnostic chart, then and only then should the SDM be replaced.