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 Frontal Deployment Loop Stage 1 Short to Battery
DTC B0012 02
- Driver Frontal Deployment Loop Stage 1 Short to Ground
DTC B0012 04
- Driver Frontal Deployment Loop Stage 1 Open
DTC B0012 0D
- Driver Frontal Deployment Loop Stage 1 High Resistance
DTC B0012 0E
- Driver Frontal Deployment Loop Stage 1 Low Resistance
DTC B0013 01
- Driver Frontal Deployment Loop Stage 2 Short to Battery
DTC B0013 02
- Driver Frontal Deployment Loop Stage 2 Short to Ground
DTC B0013 04
- Driver Frontal Deployment Loop Stage 2 Open
DTC B0013 0D
- Driver Frontal Deployment Loop Stage 2 High Resistance
DTC B0013 0E
- Driver Frontal Deployment Loop Stage 2 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 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 air bag coil connector which will short together both steering wheel air bag stage 1 high circuit and steering wheel air bag stage 1 low circuit and both steering wheel air bag stage 2 high circuit and 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 V.
Conditions for Setting the DTC
B0012 01 stage 1 or B0013 01 stage 2
The steering wheel module control circuit is shorted to voltage for 2 seconds.
B0012 02 stage 1 or B0013 02 stage 2
The steering wheel module control circuit is shorted to ground for 2 seconds.
B0012 04 stage 1 or B0013 04 stage 2
The steering wheel module control circuit is open for 2 seconds.
B0012 0D stage 1 or B0013 0D stage 2
The steering wheel module deployment loop resistance is more than 5.5 ohm for 2 seconds.
B0012 0E stage 1 or B0013 0E stage 2
The steering wheel module deployment loop resistance is less than 1.7 ohm for 2 seconds.
Action Taken When the DTC Sets
* The SDM requests the instrument cluster 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 is no longer exists.
* A history DTC will clear once 100 malfunction-free ignition cycles have occurred.
Diagnostic Aids
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 with symptom byte 04 or 0D. 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 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 connectors - on the steering wheel air bag side of the harness connector
* Harness side of the SDM connector
Reference Information
Schematic Reference
SIR Schematics ([1][2]Air Bag Systems)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
SIR System Description and Operation (SIR System Description and Operation)
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
Circuit/System Verification
Refer to SIR Service Precautions (Technician Safety Information).
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.
* Air bag
* Steering wheel air bag coil.
* SDM
* Air bag wiring harness connector.
* SDM 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. Replace any CPA that is damaged or missing.
If the condition is intermittent or cannot be duplicated, disconnect the connectors and add Nyogel lubricant 760G. This procedure will correct the high resistance condition due to terminal fretting corrosion.
1. Observe the scan tool Deployment Loop Resistance 1 and 2 parameters while turning the steering wheel 360 degrees in one direction then back 360 degrees in the other direction. The reading should stay consistently between 2.1 and 4.0 ohm without any spikes or dropouts.
2. Observe the scan tool Deployment Loop Resistance 1 and 2 parameters while moving the harness near each connector listed below. The reading should stay consistently between 2.1 and 4.0 ohm without any drop outs or spikes.
* X85 Steering wheel air bag coil
* F107 Steering wheel air bag.
* Any harness inline
* K36 SDM
• 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 Nyogel lubricant 760G to each connector terminal.
- Ensure each connector and CPA is correctly seated.
Circuit/System Testing
Refer to SIR Service Precautions (Technician Safety Information).
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.
* Air bag
* Steering wheel air bag coil.
* SDM
* Air bag wiring harness connector.
* SDM 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. Replace any CPA that is damaged or missing.
If the condition is intermittent or cannot be duplicated, disconnect the connectors and add Nyogel lubricant 760G. This procedure will correct the high resistance condition due to terminal fretting corrosion.
1. Ignition OFF, disconnect the harness connector at the appropriate F107 steering wheel air bag.
2. Ignition OFF, disconnect the scan tool, wait 120 seconds, test for greater than 25 ohm between the control circuit terminal 1 and the control circuit terminal 2.
• If less than the specified range, test for a short between the control circuits, check each connector and CPA to ensure the shorting bars are lifted. If the circuits and shorting bars tests normal, replace the K36 SDM.
3. Ignition ON, verify the scan tool Deployment Loop Resistance parameter is greater than 25 ohm.
• If less than the specified range, test the control circuit terminal 1 for a short to ground. If the circuit tests normal, replace the K36 SDM.
4. Install a 3 A fused jumper wire between the control circuit terminal 1 and the control circuit terminal 2.
5. Observe the scan tool Deployment Loop Resistance parameter while turning the steering wheel 360 degrees in one direction then back 360 degrees in the other direction. Verify the scan tool Deployment Loop Resistance parameter is consistently less than 2 ohm.
• If the reading is erratic while turning the steering wheel, replace the X85 steering wheel airbag coil.
• If greater than the specified value, test the steering wheel airbag coil for an open/high resistance and the control circuit terminals 1 and 2 for a short to voltage or an open/high resistance. If the steering wheel airbag coil and the circuits test normal, replace the K36 SDM.
6. If all circuits test normal, replace the F107 steering wheel air bag.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Steering Wheel Inflatable Restraint Module Coil Replacement (Removal and Replacement)
* Steering Wheel Inflatable Restraint Module Replacement (Steering Wheel Inflatable Restraint Module Replacement)
* SIR/SRS Wiring Repairs (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming