Circuit Description
The inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) contains a sensing device which converts vehicle velocity changes 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 steering wheel module, deploying the driver air bag and causing DTC 66 to set.
Conditions for Setting the DTC
The inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) detects a front crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the air bags.
Action Taken When the DTC Sets
| • | The SDM turns ON the AIR BAG warning lamp. |
| • | The SDM records the Crash Data. |
| • | The SDM sets a DTC 66. |
Conditions for Clearing the DTC
DTC 66 cannot be cleared. You must replace the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM).
Test Description
The numbers below refer to the step numbers on the diagnostic table:
-
This test checks to see if the inflatable restraint steering wheel module has deployed.
-
This test checks for damage to the front of the vehicle and the undercarriage. If the inflatable restraint steering wheel module has not deployed and there are no signs of damage to the vehicle, the SDM may be malfunctioning.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Turn the ignition switch to the OFF position. Has the inflatable restraint steering wheel module deployed? | -- | |||
3 |
Have all current and history SIR DTCs been cleared? | -- | -- | |
Are any signs of impact evident? | -- | |||
5 |
Is the repair complete? | -- | -- |
