For 1990-2009 cars

### Circuit Description

SIR sensing and diagnostic module consists a detecting device, which can transmit the change of speed into electrical signals. SDM processes the occurred electrical signal and compare it 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. When the inflation circuit has faults, which may result in failure of one or more inflation modules to deploy, DTC B0053 rather than DTC B0052 sets.

### DTC Descriptor

The diagnostic procedure supports the following DTC:

DTC B0053 Command Deployment When Deployment Loop DTC Sets

### Conditions for Running the DTC

There is ignition 1 voltage.

### Conditions for Setting the DTC

When the deployment loop fails, SDM commands the inflation module to deploy the air bag.

### Action Taken When the DTC Sets

• | The SDM will set DTC B0052.

• | The SDM will set DTC B0053.

• | 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 B0053 is locked DTC. The locked DTC can not be cleared. After performing the steps in the diagnostic table, replace the SDM.

### Diagnostic Aids

Important: The seat belt pretensioner may explode when the crash is not very serious, which may deploy the frontal or side airbag. SDM may bear 3 times of pretensioner explosion, one frontal or side airbag deployment. When it reaches the maximum deployment times, DTC B0053 is locked, which can not be cleared.

When DTC B0053 sets at the same time with other DTCs, except DTC B0052, please correct the fault setting the other DTCs before replacing 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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