GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2004 🢒 GTO 🢒 DTC 🢒 DTC 37 or 38

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 used in the inflatable restraint I/P module connector which will short together the I/P 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 I/P 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 37 will set when the SDM detects a high resistance condition in the I/P module deployment loop.
    • DTC 38 will set when the SDM detects a low resistance 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:

    • An open or high resistance in the I/P module high or the I/P module low circuits.
    • A short between the I/P module high and 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. Tests to see if the malfunction is caused by the inflatable restraint I/P module.

    2.

  2. If DTC 37 is present, test the I/P module high and the I/P module low circuits for an open or high resistance.

    If DTC 38 is present, test for a short between the I/P module high and the I/P module low circuits.

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 37 or 38 set as a current DTC?

Go to Step 3

Go to Diagnostic Aids

3
  1. Turn OFF the ignition.
  2. Disconnect the instrument panel (I/P) module connector.
  3. Inspect both the component and harness sides of the I/P module connectors for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Does the connector exhibit any signs of damage or corrosion?

Go to Step 4

Go to Step 5

4
  1. If the component side of the I/P module connector is damaged, the I/P module must be replaced. Refer to Inflatable Restraint Instrument Panel Module Replacement .
  2. If the harness side of the I/P module connector is damaged, replace the harness side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the replacement?

Go to Step 10

--

5

  1. Install EL-46867 SIR Driver/Passenger Load Tool to the I/P module harness connector.
  2. Connect the battery. Refer to Battery Negative Cable Disconnection and Connection in Engine Electrical.
  3. Use the scan tool in order to Clear the DTCs.
  4. With the scan tool request the DTC display.

Does the scan tool indicate that DTC 37 or 38 is current?

Go to Step 6

Go to Step 8

6
  1. Turn OFF the ignition.
  2. Disconnect the sensing and diagnostic module (SDM) connector.
  3. Inspect the SDM connector for damage or corrosion that may cause a malfunction between the I/P module high and/or the I/P module low circuits. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 7

7

    • If DTC 37 is present, test the I/P module high and the I/P module low circuits for an open or high resistance.
    • If DTC 38 is present, test for a short between the I/P module high and the I/P module low circuits.
    • All the above conditions refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 10

Go to Step 9

8
  1. Turn OFF the ignition.
  2. Replace the I/P module. Refer to Inflatable Restraint Instrument Panel Module Replacement .

Did you complete the replacement?

Go to Step 10

--

9

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

Did you complete the replacement?

Go to Step 10

--

10
  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