For 1990-2009 cars

### Circuit Description

The inflatable restraint sensing and diagnostic module (SDM) contains a sensing device (Accelerometer) that converts vehicle velocity changes into an electrical signal. The SDM compares this electrical signal to a value stored in memory. When the generated signal exceeds the stored value, the SDM performs additional signal processing and compares the generated signals to values stored in memory. When two of the generated signals exceed the stored values, the SDM will cause current to flow through the inflator modules, deploying the air bags, and causing DTC B1051 to set.

### Conditions for Running the DTC

Ignition 1 Voltage is within the normal operating voltage range.

### Conditions for Setting the DTC

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

### Action Taken When the DTC Sets

• | The SDM commands the AIR BAG indicator ON.

• | The SDM records crash data.

### Conditions for Clearing the DTC

DTC B1051 is a latched code which cannot be cleared. Replace the SDM after following the instructions in the diagnostic table.

### Test Description

The number(s) below refer to the step number(s) on the diagnostic table:

1. This step checks for evidence of inflator module deployment. If no evidence of inflator module deployment exists, DTC B1051 may have set falsely.

2. This step checks for signs of impact or collision. If there are no signs of impact or collision, DTC B1051 may have set falsely.

Step | Action | Yes | No
--- | --- | --- | ---
1 | Did you perform A Diagnostic System Check - SIR? | Go to Step 2 | Go to Diagnostic System Check - SIR
2 |

1. Turn OFF the ignition.
2. Inspect the vehicle for signs of inflator module deployment.

Does the vehicle show any signs of inflator module deployment?

Go to Step 5

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 5 | Go to Step 4
4 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | Go to Step 6 | --
5 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.
3. With the scan tool request the SIR DTC display.
4. If a history DTC exists, refer to Diagnostic Aids for that specific DTC and diagnose the problem.
5. Replace components and perform inspections as required following an accident. Refer to Repairs and Inspections Required After a Collision .

Did you complete the appropriate inspections and necessary repairs?

Go to Step 6

--

6 |

1. Use the scan tool in order to clear the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK