Operation CHARM: Car repair manuals for everyone.

B0012




DTC B0012 or B0013

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (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 Circuit

DTC B0012 0D
- Driver Steering Wheel Air Bag Deployment Loop Stage 1 Resistance Above Threshold

DTC B0012 0E
- Driver Steering Wheel Air Bag Deployment Loop Stage 1 Resistance Below Threshold

DTC B0013 01
- Driver Steering Wheel Air Bag Deployment Loop Stage 2 Short to Battery

DTC B0013 02
- Driver Steering Wheel Air Bag Deployment Loop Stage 2 Short to Ground

DTC B0013 04
- Driver Steering Wheel Air Bag Deployment Loop Stage 2 Open Circuit

DTC B0013 0D
- Driver Steering Wheel Air Bag Deployment Loop Stage 2 Resistance Above Threshold

DTC B0013 0E
- Driver Steering Wheel Air Bag Deployment Loop Stage 2 Resistance Below Threshold

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 SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage.

There are 2 shorting bars used within the steering wheel module coil connector which will short together both driver steering wheel air bag stage 1 high circuit and driver steering wheel air bag stage 1 low circuit and both driver steering wheel air bag stage 2 high circuit and driver steering wheel air bag stage 2 low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the air bag during servicing.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0012 01 Stage 1 or B0013 01 Stage 2

The driver steering wheel air bag high and/or low circuit is short to voltage for 120 milliseconds.

B0012 02 Stage 1 or B0013 02 Stage 2

The driver steering wheel air bag high and/or low circuit is short to ground for 120 milliseconds.

B0012 04 Stage 1 or B0013 04 Stage 2

The driver steering wheel air bag high and/or low circuit is open for 120 milliseconds.

B0012 0D Stage 1 or B0013 0D Stage 2

The driver steering wheel air bag deployment loop resistance is greater than 5.1 ohms for 120 milliseconds.

B0012 0E Stage 1 or B0013 0E Stage 2

The driver steering wheel air bag deployment loop resistance is less than 1.3 ohms for 120 milliseconds.

Action Taken When the DTC Sets

* The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
* The SDM 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 no longer exists.
* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

SIR Schematics ([1][2]Air Bag Systems)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

SIR System Description and Operation (SIR System)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Connector Repairs (Connector Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning)for scan tool information.
Special Tools

J 38715-A SIR Driver/Passenger Load Tool

Circuit/System Testing

Important: Refer to SIR Service Precautions (Technician Safety Information).


When removing the connectors inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector:


* Driver steering wheel air bag

* SDM

* Driver steering wheel air bag wiring harness connector

* SDM wiring harness connector


Important: 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.


1. Verify that the Driver steering wheel air bag connector and the CPA are engaged.

If the above condition is not found, make the appropriate repair.

2. Ignition OFF, disconnect the harness connector at the driver steering wheel air bag.
3. With the appropriate load tool adaptor, connect special tool J 38715-A in place of the driver steering wheel air bag.
4. Ignition ON, verify DTC is set as current.

If the DTC is not set or is set as history, cycle ignition OFF, disconnect the adapter and J 38715-A , reconnect the harness connector at the driver steering wheel air bag, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the driver steering wheel air bag.

5. Ignition OFF, disconnect special tool J 38715-A and adaptor.
6. Disconnect the in-line harness connector at the steering wheel module coil.
7. With the appropriate load tool adaptor, connect special tool J 38715-A .
8. Ignition ON, with a scan tool, verify DTC is set as current.

If DTC is not set or is set as history, replace the steering wheel module coil.

9. Ignition OFF, disconnect special tool J 38715-A and adaptor.
10. Ignition ON, test for less than 1 volt between the appropriate high control circuit listed below and ground:

* Steering wheel module coil connector Stage 1 terminal A1 X250
* Steering wheel module coil connector Stage 2 terminal B1 X250

If greater than the specified range, test the circuit for a short to voltage.

11. Test for less than 1 volt between the appropriate low control circuit listed below and ground:

* Steering wheel module coil connector Stage 1 terminal A2 X250
* Steering wheel module coil connector Stage 2 terminal B2 X250

If greater than the specified range, test the circuit for a short to voltage.

12. Ignition OFF, test for infinite resistance between the appropriate high control circuit listed below and ground:

* Steering wheel module coil connector Stage 1 terminal A1 X207
* Steering wheel module coil connector Stage 2 terminal B1 X207

If not the specified value, test the circuit for a short to ground.

13. Test for infinite resistance between the appropriate low control circuit listed below and ground:

* Steering wheel module coil connector Stage 1 terminal A2 X207
* Steering wheel module coil connector Stage 2 terminal B2 X207

If not the specified value, test the circuit for a short to ground.

14. Disconnect the harness connector at the SDM.
15. Test for less than 1 ohm between the appropriate high control circuit terminals listed below:

* Steering wheel module coil harness connector Stage 1 terminal A1 X250 and SDM terminal 9
* Steering wheel module coil harness connector Stage 2 terminal B1 X250 and SDM terminal 5

If greater than the specified range, test the circuit for an open/high resistance.

16. Test for less than 1 ohm between the appropriate low control circuit terminals listed below:

* Steering wheel module coil connector Stage 1 terminal A2 X250 and SDM terminal 8
* Steering wheel module coil connector Stage 2 terminal B2 X250 and SDM terminal 4

If greater than the specified range, test the circuit for an open/high resistance.

17. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Steering Wheel Inflatable Restraint Module Replacement (Steering Wheel Inflatable Restraint Module Replacement)
* Steering Wheel Inflatable Restraint Module Coil Replacement (Coil) (Removal and Replacement)
* SIR/SRS Wiring Repairs (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning)for SDM replacement, setup, and programming