Circuit Description
The inflatable restraint sensing and diagnostic module (SDM) contains sensing devices that convert vehicle velocity changes to electrical signals. The SDM processes the generated electrical signals and compares them to values stored in memory. When the generated signals exceed the stored values, the SDM performs additional signal processing and compares the generated signals to signals stored in memory. When 2 of the generated signals exceed the stored values, the SDM will cause current to flow through the deployment loops, deploying the air bags and/or pretensioners. Diagnostic trouble code (DTC) B0053 will set along with DTC B0051 when a deployment occurs while a circuit malfunction is present in any one of the deployment loops.
Important: The seat belt pretensioners may deploy for impacts that are not severe enough to warrant frontal or side air bag deployment. The SDM is capable of sustaining 3 pretensioner deployment events, or 1 frontal or side deployment event. After the maximum number of deployments has occured, DTC B0051and B0053 become latched codes, which cannot be cleared.
Conditions for Running the DTC
Ignition 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
The DTC will set if one of the following conditions occurs:
| • | The SDM detects a frontal impact of sufficient force to warrant deployment of the frontal inflator modules and/or pretensioners. |
| • | The SDM detects a side impact of sufficient force to warrant deployment of a roof rail inflator module. |
Action Taken When the DTC Sets
| • | The SDM sets DTC B0051. |
| • | The SDM commands the AIR BAG indicator ON via Class 2 serial data. |
| • | The SDM records crash data. |
Conditions for Clearing the DTC
DTC B0053 can be cleared if the following conditions are met.
| • | Three consectutive seat belt pretensioner deployment events have not occurred. |
| • | One frontal or side air bag deployment has not occurred. |
| • | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
DTC B0053 becomes a latched code after 3 consecutive pretensioner deployment events or 1 frontal or side air bag deployment. You cannot clear a latched code. Replace the SDM after following the instructions in the Diagnostic table.
Diagnostic Aids
DTC B0053 will be accompanied by another DTC, other than DTC B1000 and DTC B0051. Repair the malfunction causing the other DTCs before installing a new SDM.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: SIR Schematics | |||
1 | Did you perform the Diagnostic System Check - SIR? | Go to Step 2 | |
2 |
Does the vehicle show any signs of inflator module or pretensioner deployment? | Go to Step 4 | Go to Step 3 |
3 | Inspect the front of the vehicle and undercarriage for signs of impact/collision. Does the vehicle show any signs of impact/collision? | Go to Step 4 | Go to Step 5 |
4 |
Did you complete the action? | Go to Step 5 | -- |
5 | Use the scan tool to attempt to Clear DTC B0053. Has DTC B0053 been cleared successfully? | Go to Step 7 | Go to Step 6 |
6 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | Go to Step 7 | -- |
7 |
Does the DTC reset? | Go to Step 2 | System OK |
