GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The inflatable restraint instrument panel (I/P) module deployment loop consists of a inflatable restraint I/P module, the I/P module high and I/P module low circuits. A shorting bar is used in the inflatable restraint I/P module connector which will short together the I/P module high and I/P module low circuits when the connector is disconnected, this will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the inflatable restraint steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored.

Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

Conditions for Setting the DTC

    • DTC 35 will set when the SDM detects a high capacitance condition in the I/P module deployment loop.
    • DTC 36 will set when the SDM detects a low capacitance condition in the I/P module deployment loop.

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.

Diagnostic Aids

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction.

The following are possible causes of the malfunction:

    • A high capacitance in the inflatable restraint I/P module inline capacitor
    • A low capacitance in the inflatable restraint I/P module inline capacitor

If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

Connector End View Reference: SIR Connector End Views

1

Did you perform a Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2

Is DTC 35 or 36 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3

Replace the instrument panel (I/P) module jumper harness.

Did you complete the replacement?

Go to Step 4

--

4

  1. Reconnect all SIR components.
  2. Verify that all components, connectors and 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