GM Service Manual Online
For 1990-2009 cars only

Circuit Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.

In case of air bag inflation by a vehicle collision, the SDM maintains the warning lamp ON and then all the air bag systems including the SDM, air bag module, and wiring should be replaced.

Conditions for Setting the DTC

The history of air bag inflation or belt pretensioner explosion is in the SDM.

Step

Action

Yes

No

Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section.

Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section.

 

1

Perform the Diagnostic System Check - SIR.

Is the Diagnostic System Check - SIR complete?

Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Disconnect the negative battery cable.
  2. Replace the sensing and diagnostic module (SDM).

Is the repair complete?

Go to Diagnostic System Check - SIR

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