Circuit Description
The inflatable restraint sensing and diagnostic module (SDM) receives a signal fron the inflatable restraint side impact sensor (LH) which contains a sensing device which converts changes in velocity at the LH B-pillar to an electrical signal. The electrical signal detected is processed by the SDM and then compared to a value stored in memory. When the generated signal exceeds the stored value, additional signal processing is performed and the generated signals are compared to signals stored in memory. When two of the generated signals exceed the stored values, the SDM causes current to flow through the inflatable restraint driver seat inflator module, deploying the driver side air bag and causing DTC B1057 to set. When DTC B1057 has been set, communication with the inflatable restraint side impact sensor (LH) will be disabled until the fault is cleared.
Conditions for Setting the DTC
The inflatable restraint sensing and diagnostic module (SDM) detects a side impact of sufficient force to warrant deployment of the driver side air bag.
Action Taken When the DTC Sets
| • | The SDM sets a DTC B1057. |
| • | The SDM turns ON the AIR BAG warning lamp. |
| • | The SDM records the crash data. |
Conditions for Clearing the DTC
Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the Current DTC B1057 to set are no longer existing, History DTC B1057 will set. History DTC B1057 may be cleared using the scan tool. The SDM must be replaced after three driver side air bag deployments or if Current DTC B1057 cannot be cleared.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
If the inflator module(s) has not deployed, DTC B1057 may have set falsely.
-
If DTC B1057 has set with no signs of frontal impact, the DTC has set falsely.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Turn the ignition switch to the OFF position. Has the driver side air bag inflator module deployed? | -- | |||
Inspect the front of the vehicle and the undercarriage for signs of impact. Are there signs of impact? | -- | |||
4 | Replace the inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | -- | |
5 | Replace components and perform inspections as required following an accident. Refer to Repairs and Inspections Required After a Collision . Have the appropriate inspections and repairs been made? | -- | -- | |
6 | Reconnect all the SIR system components, making sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- |
