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.

Upon passing this 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 deployment loops.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC 012 Driver Pretensioner Deployment Loop Short to Voltage

Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

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.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Step

Action

Values

Yes

No

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

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

Schematic Reference: SIR Schematics

Connector End View Reference: Component Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Disconnect the negative battery cable.
  2. Wait 1 minute for the sensing and diagnostic module (SDM) capacitor to discharge.
  3. Visually inspect the supplemental inflatable restraints (SIR) wiring harness.

Is there any visible damage to the SIR wiring harness?

--

Go to Step 3

Go to Step 4

3

Replace the SIR wiring harness.

Did you complete the repair?

--

Go to Step 7

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4

  1. Disconnect the electrical connector from the driver seat belt pretensioner module.
  2. Disconnect the electrical connector at the SDM.
  3. The shorting bar at the disconnected SDM connector will create a complete circuit between the wires from the driver seat belt pretensioner module.

  4. Measure the voltage at each of the terminals on the SDM side of the driver seat belt pretensioner module connector.

Does the voltage measure greater than the specified value?

0 V

Go to Step 3

Go to Step 5

5

  1. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement.
  2. Reconnect the negative battery cable.
  3. Use the scan tool in order to clear the DTCs.
  4. Perform the Diagnostic System Check - Vehicle.

Is DTC 012 still shown as a current fault?

--

Go to Step 6

Go to Step 7

6

Replace the driver seat belt pretensioner.

Did you complete the replacement?

--

Go to Step 7

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7

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

Does the DTC reset?

--

Go to Step 2

System OK