For 1990-2009 cars

### Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device that converts vehicle velocity changes to an electrical signal. The SDM processes the generated electrical signal and compares the signal to a value stored in memory. If the generated signal exceeds the stored value, 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 inflator modules, deploying the air bags. DTC B1053 will set instead of a DTC B1051 when a deployment occurs while an inflator circuit fault is present that may possibly result in a non-deployment situation in one or both inflator modules.

### Conditions for Setting the DTC

The SDM detects a frontal crash, up to 30 degrees off the centerline on the vehicle, of sufficient force to warrant deployment of the air bags.

### Action Taken When the DTC Sets

• | The SDM detects a diagnostic trouble code.

• | The SDM turns ON the AIR BAG Warning Indicator.

• | The SDM records crash data.

### Conditions for Clearing the DTC

DTC B1053 is a latched code. Latched codes cannot be cleared. Replace the SDM after following the instructions in the diagnostic table.

### Diagnostic Aids

DTC B1053 will be accompanied by another DTC (other than DTC B1071). Repair the malfunction causing the other DTC(s) before installing a new SDM.

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. If the inflator module(s) has not deployed, DTC B1053 may have set falsely.

2. If DTC B1053 has set with no signs of frontal impact, the DTC has set falsely.

#### DTC B1053 Deploy Commanded w/Loop Malfunction

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the SIR Diagnostic System Check performed? | -- | Go to Step 2 | Go to SIR Diagnostic System Check
2 | Turn the ignition switch to the OFF position. Has the inflator modules deployed? | -- | Go to Step 5 | Go to Step 3
3 | Inspect the front of the vehicle and the undercarriage for signs of impact. Are there signs of impact? | -- | Go to Step 5 | Go to Step 4
4 | Replace the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Is the repair complete? | -- | Go to Step 6 | --
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? | -- | Go to Step 6 | --
6 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to SIR Diagnostic System Check | --