For 1990-2009 cars

### Circuit Description

The inflatable restraint Sensing and Diagnostic Module (SDM) contains a sensing device 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 B0051 to set.

This DTC is set when the inflatable restraint sensing and diagnostic module (SDM) has commanded an air bag deployment with no faults present.

### Conditions for Running the DTC

Ignition 1 voltage must be present.

### Conditions for Setting the DTC

Ignition voltage must be present and the inflatable restraint sensing and diagnostic module (SDM) must have commanded an air bag deployment.

### Action Taken When the DTC Sets

• | The SDM commands the AIR BAG warning lamp ON via Class 2 serial data.

• | The SDM records crash data.

### Conditions for Clearing the DTC

DTC B0051 is a latched code. You cannot clear a latched code. Replace the SDM after following the instructions in the diagnostic table.

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 any signs of air bag deployment.

Does the vehicle show any signs of air bag deployment?

Go to Step 5

Go to Step 3

3 | Inspect 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 inflatable restraint sensing and diagnostic module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | Go to Step 6 | --
5 | Replace all the 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. Reconnect all SIR components.
2. Verify that all components, connectors, and CPAs are properly mounted.

Did you complete the repair?

Go to Diagnostic System Check - SIR

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