GM Service Manual Online
For 1990-2009 cars only

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 2 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.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B0051 Deployment Commanded

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The DTC will set if one of the following conditions occurs:

    • The SDM detects a frontal crash of sufficient force to warrant deployment of the frontal inflator modules.
    • The SDM detects a side impact crash of sufficient force to warrant deployment of a side inflator module.

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

Schematic Reference: SIR Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

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 Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 6

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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

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6

  1. Reconnect all SIR components.
  2. Verify that all components, connectors, and connector position assurances (CPAs) are properly mounted.
  3. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

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