Circuit Description
When the inflatable restraint sensing and diagnostic module (SDM) recognizes IGNITION 1 voltage, applied to terminal 10, is greater than 8.2 volts, the SDM flashes the AIR BAG warning lamp 7 times in order to verify operation. At this time, the SDM performs the POWER-ON test followed by the RESISTANCE MEASUREMENT test and the CONTINUOUS MONITORING test. Upon detection of a malfunction, the SDM sets a current diagnostic trouble code (DTC) and illuminates the AIR BAG warning lamp. The SDM will clear current DTCs and preserve them in a history file when the following items occur:
| • | The malfunction is no longer detected. |
| • | The ignition switch is cycled. |
This does not include the following latched codes:
| • | B1018 |
| • | B1024 |
| • | B1051 |
| • | B1053 |
| • | B1071 |
You cannot clear a latched code.
Important: Repair the malfunction that set the DTC before you replace the SDM.
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 is unlikely to 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 SIR Diagnostic System Check or a diagnostic trouble code table diagnosis has been performed. When all circuitry outside the inflatable restraint sensing and diagnostic module (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 in order 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 | |
Use the Scan Tool in order to request the SIR DTC display. Is the same symptom or DTC occurring as when the SIR Diagnostic System Check 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 |
Has the SDM been replaced? | -- | Go to Step 6 | -- |
6 |
Have all of the SIR components been reconnected and properly mounted? | -- | Go to Step 7 | -- |
7 | Clear the SIR DTCs. Have the SIR DTCs been cleared? | -- | -- |
