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.

These test ignition and deployment loop voltages are measured to ensure that they are within their normal voltage ranges. The SDM monitors the voltages at the driver low and the passenger low to detect shorts to ground or voltage in the deploy loops.

The SDM inspects the wiring connection to the driver side air bag module by letting the perpetual current flow through the internal circuit and verify the resistance.

Conditions for Setting the DTC

    • The side air bag wiring of the driver high is shorted to ground.
    • The side air bag wiring of the driver low is shorted to ground.

Step

Action

Values

Yes

No

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

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

 

1

  1. Confirm the ignition switch is OFF and the sensing and diagnostic module (SDM) fuse has been removed.
  2. Wait for 1 minute for the SDM charger to be discharged.

Has the SDM discharged?

--

Go to Step 2

--

2

Visually inspect any damage for the air bag wiring.

Is the air bag wiring damaged?

--

Go to Step 4

Go to Step 3

3

Measure the resistance between the SDM and the high, low terminal of the driver side air bag module and the ground.

Is the resistance equal to the specified value?

10 K ohms

Go to Step 5

Go to Step 4

4

Replace the air bag wiring.

Is the replacement complete?

--

Go to Diagnostic System Check - SIR

--

5

  1. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Confirm the ignition switch is ON.
  3. Remove the DTC using the scan tool.
  4. Perform the Diagnostic System Check - SIR.

Is the DTC removed?

--

Go to Diagnostic System Check - SIR

Go to Step 6

6

Replace the driver side air bag module.

Is the replacement complete?

--

Go to Diagnostic System Check - SIR

--