SIR Diagnostic System Check

Diagnostic Chart:

Circuit Description
The ignition switch supplies Ignition 1 voltage to the inflatable restraint Sensing and Diagnostic Module (SDM) at terminal 5 using the SIR Fuse. When the ignition switch is first turned to the RUN position, the SDM responds by flashing the AIR BAG warning lamp seven times, then turning it OFF, while performing tests on the SIR system.

Diagnostic Aids
You must diagnose the diagnostic trouble codes in the order specified by the SIR Diagnostic System Check. Failure to do so may result in the following:
^ Extended Diagnostic Time
^ Incorrect Diagnosis
^ Incorrect Parts Replacement

Test Description
The numbers below refer to the step numbers on the diagnostic table.
1. The AIR BAG warning lamp should flash seven times after the ignition switch is first turned to the RUN position.
2. The AIR BAG warning lamp indicates improper operation. This test differentiates a warning lamp stays ON condition from a warning lamp does not come ON condition.
3. The AIR BAG warning lamp should turn OFF after flashing seven times.
4. This test checks for the proper operation of the Serial Data line.
5. This test will identify the stored diagnostic trouble codes and whether they are current or history.
7. This test checks for the proper operation of the Serial Data line. This test also identifies any stored history diagnostic trouble codes.
9. This test refers to the appropriate DTC Table Diagnostic Aids for diagnosis of the history DTCs.