SIR Diagnostic System Check

CIRCUIT DESCRIPTION
When the ignition switch is first turned to "ACC" or "ON," system voltage is applied from the CIG & RADIO and the IGN fuses to the center sensor assembly at the "DC-DC Converter" inputs, terminals "B13" and "B14", and from the ECU-B fuse, through the "AIR BAG" indicator, to the "Diagnosis and Memory Circuits," terminal "B12". The center sensor responds by illuminating the "AIR BAG" indicator for approximately six seconds while performing tests on the [1][2]SRS.

NOTES ON SYSTEM CHECK CHART
1. This test checks to see if the "AIR BAG" indicator circuit is shorted to ground.
2. The "AIR BAG" indicator should illuminate steady for six seconds and then go off if there are no [1][2]SRS faults (no DTCs).
3. The "AIR BAG" indicator will remain illuminated steady if the center sensor assembly has detected a fault and stored a DTC.
4. This test checks for proper operation of "Flash Code" diagnostics.
5. This test checks to see if the center sensor assembly detected a source voltage drop.
6. This test checks to see if the DTC is current or intermittent.
7. Improper operation of the "AIR BAG" indicator is indicated. This test checks for a fault in the TC CKT.