Circuit Description
When the ignition switch is first turned to the RUN position, the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM then performs POWER-ON tests followed by the RESISTANCE MEASUREMENT tests and the CONTINUOUS MONITORING test. Upon detection of a malfunction, the SDM sets a current diagnostic trouble code (DTC) and turns ON the AIR BAG warning lamp. The SDM will clear current DTCs and preserve them in a history file when the following items are true:
| • | The malfunction is no longer detected. |
| • | The ignition switch is cycled. |
Important: Repair the malfunction that set the DTC before you replace the SDM.
This does not include the following latched codes:
| • | DTC B1018 |
| • | DTC B1024 |
| • | DTC B1051 |
| • | DTC B1053 |
| • | DTC B1071 |
You may not clear a latched code.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This test confirms a circuit malfunction. If no current malfunction is occurring (history DTC set), refer to the Diagnostic Aids for the appropriate DTC table as indicated through the Scan Tool . Do not replace the inflatable restraint sensing and diagnostic module (SDM) for a history DTC other than DTC B1071.
-
This test inspects for a malfunction introduced into the SIR system during the diagnostic process. A malfunctioning SDM would unlikely cause a new malfunction to occur during this process.
-
When you have found all circuitry outside the SDM to operate properly, as indicated by the appropriate diagnostic table, replace the SDM.
This table assumes that the Diagnostic System Check - SIR and either a symptom table or a diagnostic trouble code table diagnosis has been performed. When all circuitry outside the SDM has been found to operate properly, as indicated by the appropriate diagnostic table, and the symptom or DTC remains current, the following diagnostic procedures must be performed to verify the need for SDM replacement.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Were you sent here from a symptom table or a diagnostic trouble code (DTC) table? | -- | Go to Step 2 | |
Does the AIR BAG warning lamp flash 7 times then go OFF? | -- | Go to Step 7 | Go to Step 3 | |
Using the Scan Tool , request the SIR DTC display. Is the same symptom or DTC occurring as when the Diagnostic System Check - SIR was first performed? | -- | Go to Step 4 | Go to the appropriate DTC table | |
Does the AIR BAG warning lamp flash 7 times then go OFF? | -- | System OK | Go to Step 5 | |
5 |
Did you complete the replacement? | -- | Go to Step 6 | -- |
6 |
Have the DTCs been cleared? | -- | -- |
