GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2001 🢒 Montana Ext. 🢒 Restraints 🢒 SIR 🢒 DTC B0026

Circuit Description

The inflatable restraint steering wheel module deployment loop consists of the inflatable restraint steering wheel module, the inflatable restraint steering wheel module coil, the steering wheel module high circuit, and the steering wheel module low circuit. A shorting bar is used in the inflatable restraint steering wheel module coil connector which shorts the steering wheel module high and steering wheel module low circuits when the connector is disconnected. This will prevent unwanted deployment of the steering wheel module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) performs continuous diagnostic tests on the deployment loop to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, the SDM will store a diagnostic trouble code (DTC).

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

The DTC will set if one of the following conditions occurs:

    • Steering wheel module high circuit is less than 2.4 volts and the steering wheel module deployment loop resistance is more than 6 ohms for 500 milliseconds during the deployment loop voltage out of range test.
    • Steering wheel module deployment loop resistance is more than 4.8 ohms for 500 milliseconds during the deployment loop resistance measurement test.

Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON via Class 2 serial data.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction free ignition cycles have occurred.

Diagnostic Aids

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

The following are possible causes of the malfunction:

    • The wire to terminal connections in the steering wheel module high circuit.
    • The wire to terminal connections in the steering wheel module low circuit.
    • The steering wheel module upper coil connector
    • The steering wheel module coil connector
    • The SDM connector
    • An internal SDM malfunction

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

Test Description

The number(s) below refer to the step number(s) on the diagnostic table.

  1. Tests to see if the malfunction is intermittent

    2.

  2. Test to see if the malfunction is caused by the steering wheel module or the steering wheel module coil.

    3.

  3. Test to see if there is an open or a high resistance in the steering wheel module high or steering wheel module low circuits.

Step

Action

Yes

No

Schematic Reference: SIR Schematics

1

Did you perform the Diagnostic System Check - SIR?

Go to Step 2

Go to Diagnostic System Check - SIR

2
  1. Turn OFF the ignition.
  2. Disconnect the steering wheel module coil connector. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .
  3. Inspect the component and harness sides of the steering wheel module coil connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Does steering wheel module coil connector exhibit any signs of damage or corrosion?

Go to Step 3

Go to Step 4

3
  1. If the component side of the steering wheel module coil connector is damaged, the steering wheel module must be replaced.
  2. If the harness side of the steering wheel module coil connector is damaged, replace the harness side of the connector. Refer to Connector Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 12

--

4

  1. Reconnect the steering wheel module coil connector.
  2. Verify that the connector position assurance (CPA) is properly installed.
  3. Install a scan tool.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the SIR DTC display.

Does the scan tool indicate that DTC B0026 is current?

Go to Step 5

Go to Diagnostic Aids

5
  1. Turn OFF the ignition.
  2. Disconnect the steering wheel module coil connector.
  3. Connect the J 38715-A BASE OF COLUMN connector to the harness side of the steering wheel module coil connector.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the SIR DTC display.

Does the scan tool indicate that DTC B0026 is current?

Go to Step 9

Go to Step 6

6

  1. Turn OFF the ignition.
  2. Disconnect the J 38715-A .
  3. Reconnect the steering wheel module coil connector.
  4. Remove the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  5. Use the J 38715-30A adaptor to connect the J 38715-A STEERING COLUMN connector to the steering wheel module coil upper connector on top of the steering column.
  6. Turn ON the ignition, with the engine OFF.
  7. With a scan tool, observe the SIR DTC display.

Does the scan tool indicate that DTC B0026 is current?

Go to Step 8

Go to Step 7

7
  1. Turn OFF the ignition.
  2. Replace the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

Go to Step 12

--

8
  1. Turn OFF the ignition.
  2. Replace the steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 12

--

9
  1. Turn OFF the ignition.
  2. Remove the J 38715-A .
  3. Disconnect the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
  4. Inspect the SDM connector for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the problem?

Go to Step 12

Go to Step 10

10

Test the steering wheel module high and steering wheel module low circuits for an open or a high resistance. Refer to Circuit Testing and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 12

Go to Step 11

11

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

Did you complete the replacement?

Go to Step 12

--

12
  1. Reconnect all SIR components.
  2. Use the scan tool in order to clear the DTCs.
  3. 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