Chart A SDM Integrity Check

Wiring Diagram:

CIRCUIT DESCRIPTION

When the SDM recognizes "Ignition 1" voltage, applied to terminal "8," is greater than 8.2 volts, the "AIR BAG" warning lamp is flashed seven times to verify operation. At this time the SDM performs "Turn-ON" tests followed by "Resistance Measurement Tests" 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 19, 25, 51, 53 and 71. DTCs 19, 25, 51 and 53 cannot be cleared. DTC 71 may not clear after a "Clear Codes" command is issued.

CHART TEST DESCRIPTION

Numbers below refer to circled numbers 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 unless as directed.

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.