SRS Diagnostic System Check

CIRCUIT DESCRIPTION
- When the ignition switch is first turned "ON", "Ignition 1" voltage is applied from the "SRS-2" fuse to the SDM at the "Ignition 1" input terminals "A8". The SDM responds by flashing the "AIR BAG" warning lamp seven times while performing tests on the SRS.





NOTES ON SYSTEM CHECK CHART:
- Number(s) below refer to step number(s) on the "SRS DIAGNOSTIC SYSTEM CHECK" chart.
1. The "AIR BAG" warning lamp should flash seven times after ignition is first turned "ON".
2. After the "AIR BAG" warning lamp flashes seven times it should turn "OFF".
3. Improper operation of the "AIR BAG" warning lamp is indicated. This test differentiates a warning lamp stays "ON" condition from a warning lamp does not come "ON" condition.
4. This test checks for the proper operation of the "Serial Data" line. This test will also determine whether history diagnostic trouble codes are stored and, if so, identify them.
5. This test checks for proper operation of the "Serial Data" line. This test will also identify the stored diagnostic trouble codes and whether they are current or history.

DIAGNOSTIC AIDS:
- The order in which diagnostic trouble codes are diagnosed is very important. Failure to diagnose the diagnostic trouble codes in the order specified may result in extended diagnostic time, incorrect diagnosis and incorrect parts replacement.