GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) contains a sensing device which converts vehicle velocity changes to an electrical signal. The SDM processes the generated electrical signals and compares them to values stored in memory. When the generated signals exceed the stored value, the SDM performs additional signal processing and compares the generated signals to signals stored in memory. When two of the generated signals exceed the stored values, the SDM causes current to flow through the inflatable restraint IP module, deploying the passenger frontal air bag and causing the DTC to set.

Conditions for Running the DTC

The ignition voltage must be within the normal operating range.

Conditions for Setting the DTC

The inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) detects a front crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the passenger frontal air bag.

Action Taken When the DTC Sets

    • The SDM turns ON the AIR BAG warning lamp.
    • The SDM records the Crash Data.

Conditions for Clearing the DTC

This DTC is latched. Replacing the SDM will clear the DTC.

Test Description

The numbers below refer to the step numbers on the diagnostic table:

  1. This step checks to see if the inflatable restraint IP module has deployed.

  2. This step determines if there is damage to the front of the vehicle and the undercarriage or if there is a malfunctioning SDM.

Step

Action

Value(s)

Yes

No

1

Did you perform A Diagnostic System Check - SIR?

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Go to Step 2

Go to Diagnostic System Check - SIR

2

  1. Turn OFF the ignition.
  2. Inspect the vehicle for signs of inflator module(s) deployment.

Does the vehicle exhibit signs of inflator module(s) deployment?

--

Go to Step 5

Go to Step 3

3

Inspect the front of the vehicle and undercarriage for signs of impact/collision.

Does the vehicle show any signs of impact/collision?

--

Go to Step 5

Go to Step 4

4

Replace the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .

Did you complete the replacement?

--

Go to Step 6

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5

  1. Install a scan tool.
  2. Use the scan tool to request the SIR DTC display.
  3. If a history DTC exists, refer to Diagnostic Aids for that specific DTC and diagnose the problem.
  4. Replace the inflatable restraint IP module. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  5. Replace the inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic and Seat Belt Pretensioner Module Replacement .
  6. Perform the repairs and inspections required following an accident. Refer to Repairs and Inspections Required After a Collision .

Did you complete the appropriate inspections and necessary repairs?

--

Go to Step 6

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6

  1. Reconnect all SIR components.
  2. Verify that all components and connectors are properly mounted.
  3. Turn ON the ignition, with the engine OFF.
  4. Use the scan tool in order to clear the DTCs.

Did you complete the action?

--

Go to Diagnostic System Check - SIR

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