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 belt pretensioner module by letting the perpetual current flow through the internal circuit and verify the resistance. If the resistance is between 2-10 kilo ohms, the defect may occur depending upon the SDM. The normal resistance is over 10 kilo ohms.

Conditions for Setting the DTC

    • The belt pretensioner wiring of the driver high is shorted to battery wiring.
    • The belt pretensioner wiring of the driver low is shorted to battery wiring.

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 to discharge the SDM charger.

Has the SDM discharged?

--

Go to Step 2

--

2

Visually inspect the connector and the wiring of the air bag.

Is the air bag wiring damaged?

--

Go to Step 5

Go to Step 3

3

Measure the resistance between the SDM and the high, low wiring of the driver belt pretensioner and the battery.

Is the resistance equal to the specified value?

10 K ohms

Go to Step 4

Go to Step 5

4

  1. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  2. Confirm the ignition switch is ON.
  3. Erase 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

5

Replace the air bag wiring.

Is the replacement complete?

--

Go to Diagnostic System Check - SIR

--

6

Replace the driver belt pretensioner. Refer to Front Seat Belt Replacement in Seat Belts.

Is the replacement complete?

--

Go to Diagnostic System Check - SIR

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