Buick Regal: DTC B0012 or B0013

Diagnostic Instructions

• Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
• Review Strategy Based Diagnosis for an overview of the diagnostic approach.
• Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0012 01

Driver Steering Wheel Air Bag Deployment Loop Stage 1 Short to Battery

DTC B0012 02

Driver Steering Wheel Air Bag Deployment Loop Stage 1 Short to Ground

DTC B0012 04

Driver Steering Wheel Air Bag Deployment Loop Stage 1 Open

DTC B0012 0D

Driver Steering Wheel Air Bag Deployment Loop Stage 1 High Resistance

DTC B0012 0E

Driver Steering Wheel Air Bag Deployment Loop Stage 1 Low Resistance

Diagnostic Fault Information

Circuit/System Description

During a frontal crash of sufficient force the Inflatable Restraint Sensing and Diagnostic Module (SDM) will allow current to flow through the deployment loop in order to deploy the driver steering wheel air bag. The Inflatable Restraint Sensing and Diagnostic Module performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. There is a shorting bar used within the driver steering wheel air bag coil connector which will short together the driver steering wheel air bag stage high circuit and driver steering wheel air bag stage low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the steering wheel air bag during servicing.

Conditions for Running the DTC

Ignition voltage is between 9 - 16 V.

Conditions for Setting the DTC

B0012 01 stage 1

The driver steering wheel air bag deployment loop is shorted to voltage for 2 seconds.

B0012 02 stage 1

The driver steering wheel air bag deployment loop is shorted to ground for 2 seconds.

B0012 04 stage 1

The driver steering wheel air bag deployment loop is open for 2 seconds.

B0012 0D stage 1

The driver steering wheel air bag deployment loop resistance is greater than 4.4 Ω for 2 seconds.

B0012 0E stage 1

The driver steering wheel air bag deployment loop resistance is less than 1.7 Ω for 2 seconds.

Action Taken When the DTC Sets

• The Inflatable Restraint Sensing and Diagnostic Module requests the instrument cluster to illuminate the AIR BAG indicator.
• The Inflatable Restraint Sensing and Diagnostic Module will store a DTC, however if an event occurs the system will still attempt deployment.

Conditions for Clearing the DTC

• The condition for setting the DTC is no longer exists.
• A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Diagnostic Aid

NOTE: The following diagnostic aids apply for both current and history DTCs.

A worn steering wheel air bag coil can cause a repeated history DTC to set. To verify this condition, turn the steering wheel 360 degrees in one direction then back 360 degrees in the other direction, multiple times, while viewing the scan tool Deployment Loop Resistance 1 and 2 parameters.

An incorrectly installed connector position assurance (CPA) or incorrectly seated connector can cause a shorting bar to short both control circuits together. Check the connectors and CPAs if a DTC with symptom byte 02 or 0E is set, to ensure the shorting bars are not causing the circuits to be shorted together. Shorting bars are used in the locations listed below:

• Steering wheel air bag assembly
• Steering wheel air bag coil assembly
• Inline harness connectors
• Harness side of the Inflatable Restraint Sensing and Diagnostic Module connector

Terminal fretting or incorrectly seated connector can cause an open/high resistance condition. Check the circuit terminals for fretting or incorrectly seated connector if a DTC with symptom byte 04 or 0D is set.

Reference Information

Schematic Reference

SIR Wiring Schematics

Connector End View Reference

Component Connector End View Index

Description and Operation

Supplemental Inflatable Restraint System Description and Operation

Electrical Information Reference

• Circuit Testing
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Connector Repairs

Scan Tool Reference

Refer to Control Module References for scan tool information.

Special Tools

EL-38125-580 Terminal Release Tool Kit

Circuit/System Verification

NOTE: Refer to SIR Service Precautions.

Inspect all terminals for damage or corrosion when disconnecting connectors.

Damage or corrosion in the following requires repair or replacement of the affected component/connector.

• Steering Wheel Air bag
• Steering wheel air bag coil
• Inflatable Restraint Sensing and Diagnostic Module
• Air bag wiring harness connector
• Inflatable Restraint Sensing and Diagnostic Module wiring harness connector

NOTE: The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly.

If the condition is intermittent or cannot be duplicated, disconnect the connectors and add dielectric grease / lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087). This procedure will correct the high resistance condition due to terminal fretting corrosion.

1. Verify the appropriate scan tool Deployment Loop Resistance parameter stays consistently between 2.1 and 4.0 Ω without any spikes or dropouts while turning the steering wheel 360 degrees in one direction then back 360 degrees in the other direction.

• If less than 2.1 or greater than 4.0 Ω

Refer to Circuit/System Testing.

• If there are spikes or dropouts

Replace the X85 Steering Wheel Air Bag Coil.

• Go to next step: If within 2.1 and 4.0 Ω without any spikes or dropouts

2. Verify DTC B0012 is only set as a history DTC.

• If the DTC is set as current

Refer to Circuit/System Testing.

• Go to next step: If the DTC is set as history

3. Verify the scan tool Deployment Loop Resistance parameter stays consistently between 2.1 and 4.0 Ω without any drop outs or spikes while moving the harness near each connector listed below.

• X85 Steering Wheel Air Bag Coil
• F107 Steering Wheel Air Bag
• Any inline harness connector
• K36 Inflatable Restraint Sensing and Diagnostic Module
• If the reading is erratic while moving the harness, perform the following:
• Inspect each connector terminal for damage or corrosion and repair as necessary.
• Apply dielectric grease / lubricant (Nyogel 760G or equivalent, meeting GM specification 9986087) to each connector terminal.
• Insure each connector and CPA is correctly seated.
• Go to next step: If within 2.1 and 4.0 Ω without any spikes or dropouts

4. All OK.

Circuit/System Testing

1. Ignition OFF, disconnect the scan tool and disconnect the F107 Steering Wheel Air Bag harness connector.

It may take up to 2 minutes for all vehicle systems to power down.

2. Test for greater than 25 Ω between the control circuit terminal 1 and the control circuit terminal 2.

• If 25 Ω or less

1. Disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module.

NOTE: Some connectors may be equipped with shorting bars as a safety component to prevent accidental inflator deployment. When testing on a connector with shorting bars, the shorting bars must be disabled to ensure accurate test results. Insert an appropriate pick from EL- 38125-580 and depress the shorting bars above the appropriate terminals. This will lift the shorting bar from the terminal and allow accurate test results. Take care not to damage the connector, shorting bar, or terminal when depressing the shorting bar.

2. Test for infinite resistance between the two control circuits.
   • If less than infinite resistance, repair the short between the two circuits.
   • If infinite resistance, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If greater than 25 Ω

3. Ignition ON.

4. Test for less than 11 V between the control circuit terminals listed below and ground:

• Control circuit terminal 1
• Control circuit terminal 2
• If 11 V or greater

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
   • If 1 V or greater, repair the short to voltage on the circuit.
   • If less than 1 V, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If less than 11 V

5. Ignition OFF.

6. Test for greater than 25 Ω between the control circuit terminals listed below and ground:

• Control circuit terminal 1
• Control circuit terminal 2
• If 25 Ω or less

1. Disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module.
2. Test for infinite resistance between the control circuit and ground.
   • If less than infinite resistance, repair the short to ground on the circuit.
   • If infinite resistance, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If greater than 25 Ω

7. Ignition OFF, install a 3 A fused jumper wire between the control circuit terminal 1 and the control circuit terminal 2, ignition ON.

8. Verify the scan tool Deployment Loop Resistance parameter is consistently less than 2 Ω while turning the steering wheel 360 degrees in one direction then back 360 degrees in the other direction.

• If the reading is erratic while turning the steering wheel

Replace the X85 Steering Wheel Air Bag Coil.

• If 2 Ω or greater

1. Ignition OFF, disconnect the X1 harness connector at the K36 Inflatable Restraint Sensing and Diagnostic Module.
2. Test for less than 2 Ω in the X85 Steering Wheel Air Bag Coil and each control circuit end to end.
   • If 2 Ω or greater, replace the coil or repair the open/high resistance in the circuit.
   • If less than 2 Ω, replace the K36 Inflatable Restraint Sensing and Diagnostic Module.

• Go to next step: If less than 2 Ω

9. Ignition OFF, connect the harness connector at the F107 Steering Wheel Air Bag, press in the CPA (if equipped) until an audible and/or tactile click is heard.

10. Ignition ON, clear DTCs. Operate the vehicle within the Conditions for Running the DTC.

11. Verify DTC B0012 or B0013 is not set.

• If DTC B0012 or B0013 is set

Replace the F107 Steering Wheel Air Bag.

• Go to next step: If DTC B0012 or B0013 is not set

12. All OK.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• Steering Wheel Airbag Replacement
• Steering Wheel Airbag Coil Replacement
• SIR/SRS Wiring Repairs
• Control Module References for Inflatable Restraint Sensing and Diagnostic Module replacement, programming and setup

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