For 1990-2009 cars

### Circuit Description

Inflatable Restraint Sensing and Diagnostic module (SDM) includes a detecting device. It can transfer the change of speed into electrical signals. SDM compares the signal with the value stored in the memory. When the detected signal is larger than the stored value, SDM will conduct additional signal treatment and compare it with the value in the memory. When both of the signal values are larger than the stored value, SDM will allow the current to flow through the deployment loop to deploy the airbag and set DTC B0055.

The SDM commands an airbag to deploy, when there is not fault, the DTC will set.

### DTC Descriptor

The diagnostic procedure supports the following DTC:

DTC B0055 Command Side Airbag to Deploy

### Conditions for Running the DTC

There is ignition 1 voltage.

### Conditions for Setting the DTC

Ignition voltage must exist and the SDM must command an air bag to deploy.

### Action Taken When the DTC Sets

• | The SDM will set DTC B0055.

• | The SDM commands the AIR BAG indicator ON via GMLAN serial data communications.

• | The SDM will record the striking data.

### Conditions for Clearing the DTC

DTC B0055 is locked DTC. The locked DTC can not be cleared. After performing the steps in the diagnostic table, replace the SDM.

Step | Action | Yes | No
1 | Have you conducted Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Turn the ignition switch to OFF position.
2. Check if the vehicle has any sign of air bag deployment.

Does the vehicle display any sign of air bag deployment?

Go to Step 5

Go to Step 3

3 | Check if the vehicle has frontal and chassis striking/impact. Does the vehicle display any sign of striking/impact? | Go to Step 5 | Go to Step 4
4 |

1. Turn the ignition switch to OFF position.
2. Replace SIR system sensing and diagnostic module (SDM). Refer to Control Module References for replacement, set up and programming.

Have you finished the replacement?

Go to Step 6

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5 | Replace the components according to requirement after collision and check to verify. Refer to Repairs and Inspections Required After a Collision . Have you finished relevant inspection and necessary repairs? | Go to Step 6 | --
6 |

1. Reconnect all SIR components.
2. Verify all components, connectors and CPAs are correctly installed.

Is the trouble corrected?

Go to Diagnostic System Check - Vehicle

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