Chart A SDM Integrity Check

Wiring Diagram:

CIRCUIT DESCRIPTION

When the SL)M recognizes Ignition 1 voltage, applied to terminal "10." is greater than 8.2 volts, the "AIR BAG" indicator is flashed seven times (via the serial data line) to verify operation. At this time the SDM performs "Turn-ON" tests followed by "Resistance Measurement Test" and "Continuous Monitoring" tests. When a malfunction is detected, the SDM sets a current diagnostic trouble code and illuminates the "AIR BAG" indicator. 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 18, 24, 51, 57 and sometimes 71. DTC 18, 24, 51, and 53 will lot clear using a scan tool "Clear Codes" command. All of these DTCs require SDM replacement. Replace the SDM only after the malfunction that set the DTC has been repaired.

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 DTC except when 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.