GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 DTC 🢒 DTC 33 or 34

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 33 will set when the SDM detects a short to voltage in the I/P module deployment loop.
    • DTC 34 will set when the SDM detects a short to ground 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 short to voltage in the I/P module high or the I/P module low circuits
    • A short to ground in the I/P module high or the I/P module low circuits
    • A malfunctioning inflatable restraint I/P module
    • An internal SDM malfunction

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

Test Description

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

  1. Test the I/P module high and the I/P module low circuits for a short to voltage.

    2.

  2. Test to see if the malfunction is caused by the inflatable restraint I/P module.

    3.

  3. Test the I/P module high and the I/P module low circuits for a short to ground.

Step

Action

Value(s)

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 33 or 34 set as a current DTC?

--

Go to Step 3

Go to Diagnostic Aids

3

Is DTC 33 set as a current DTC?

--

Go to Step 4

Go to Step 5

4

  1. Turn OFF the ignition.
  2. Disconnect the instrument panel (I/P) module connector.
  3. Disconnect the sensing and diagnostic module (SDM) connector.
  4. Test the I/P module high and the I/P low circuits for a short to voltage using EL-46863 Test Leads. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 12

Go to Step 11

5

Is DTC 34 set as a current DTC?

--

Go to Step 6

--

6

Use the scan tool to display the passenger deployment loop resistance.

Does the resistance display within the specified range?

Approximately 1.6-6.4 ohms

Go to Step 7

Go to Step 8

7
  1. Remove the I/P compartment. Refer to Instrument Panel Compartment Door Replacement in Instrument Panel, Gages, and Console.
  2. Use the scan tool in order to Clear the DTCs.
  3. Use the scan tool in order to Read the DTCs.
  4. Wiggle the wiring harness between the SDM and the I/P module while observing the scan tool.

Did the DTC status change from NO DTCs?

--

Go to Step 10

Go to Step 13

8

  1. Turn OFF the ignition.
  2. Remove the I/P compartment. Refer to Instrument Panel Compartment Door Replacement in Instrument Panel, Gages, and Console.
  3. Install EL-46867 SIR Driver/Passenger Load Tool to the I/P module harness connector.
  4. Connect the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  5. Use the scan tool to display the passenger deployment loop resistance.

Does the resistance display as specified?

Approximately 3.0 ohms

Go to Step 11

Go to Step 9

9

Test the I/P module high and the I/P module low circuits for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

Go to Step 12

10

Locate and repair intermittent short to ground in wiring harness. Refer to Testing for Intermittent Conditions and Poor Connections , Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 13

--

11

Replace the I/P module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you complete the replacement?

--

Go to Step 13

--

12

Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .

Did you complete the replacement?

--

Go to Step 13

--

13
  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