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.

The 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 passenger air bag module by letting the infinitesimal current flow through the internal circuit and verify the resistance. If the resistance is in the 2 kilo ohms between 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 air bag wiring of passenger high is shorted to ground.
    • The air bag wiring of passenger low is shorted to ground.

Step

Action

Values

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?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

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

Is there any visible damage to the SIR harness?

--

Go to Step 3

Go to Step 4

3

  1. Replace the SIR wiring harness.
  2. Reconnect the negative battery cable.

Is the repair complete?

--

Go to Diagnostic System Check - SIR

--

4

  1. Disconnect the electrical connector from the passenger air bag module.
  2. Disconnect the electrical connector at the sensing and diagnostic module (SDM).
  3. The shorting bar at the disconnected SDM connector will create a complete circuit between the wires from the passenger side air bag module.

  4. Use an ohmmeter to measure the continuity between ground and one of the terminals at the SDM side of the wiring harness connector for the passenger side air bag module.

Is the resistance less than the specified value?

Go to Step 3

Go to Step 5

5

  1. Replace the SDM.
  2. Reconnect the negative battery cable.
  3. Set the scan tool to CODE ERASE.
  4. Perform the Diagnostic System Check - SIR.

Is DTC 007 still shown as a current fault?

--

Go to Step 6

System OK

6

  1. Replace the passenger side air bag module.
  2. Reconnect the negative battery cable.

Is the repair complete?

--

Go to Diagnostic System Check - SIR

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