For 1990-2009 cars

### 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 Frontal Deployment Loop Stage 1 Short to Battery
DTC B0012 02: Driver Frontal Deployment Loop Stage 1 Short to Ground
DTC B0012 08: Driver Frontal Deployment Loop Stage 1 Signal Invalid
DTC B0012 0D: Driver Frontal Deployment Loop Stage 1 Resistance Above Threshold
DTC B0012 0E: Driver Frontal Deployment Loop Stage 1 Resistance Below Threshold
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 08: Driver Frontal Deployment Loop Stage 2 Signal Invalid
DTC B0013 0D: Driver Frontal Deployment Loop Stage 2 Resistance Above Threshold
DTC B0013 0E: Driver Frontal Deployment Loop Stage 2 Resistance Below Threshold

### Diagnostic Fault Information

Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance
--- | --- | --- | --- | --- | ---
Steering Wheel Module Stage 1 High Control | B0012 02 | B0012 0D | B0012 08 | B0012 01 | B0012 0E
Steering Wheel Module Stage 1 Low Control | B0012 02 | B0012 0D | B0012 08 | B0012 01 | B0012 0E
Steering Wheel Module Stage 2 High Control | B0013 02 | B0013 0D | B0013 08 | B0013 01 | B0013 0E
Steering Wheel Module Stage 2 Low Control | B0013 02 | B0013 0D | B0013 08 | B0013 01 | B0013 0E

### 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 module. 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 steering wheel module stage 1 high circuit and steering wheel module stage 1 low circuit and both steering wheel module stage 2 high circuit and steering wheel module stage 2 low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module 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 steering wheel module high and/or low control circuit is shorted to voltage for 2 seconds.

#### B0012 02 Stage 1 or B0013 02 Stage 2

The steering wheel module high and/or low control circuit is shorted to ground for 2 seconds.

#### B0012 08 Stage 1 or B0013 08 Stage 2

The steering wheel module high and/or low control circuit is invalid during SDM initialization.

#### B0012 0D Stage 1 or B0013 0D Stage 2

The steering wheel module deployment loop resistance is more than 5.5 ohms for 2 seconds.

#### B0012 0E Stage 1 or B0013 0E Stage 2

The steering wheel module deployment loop resistance is less than 1.7 ohms for 2 seconds.

### 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 is no longer present

• | A history DTC will clear after 100 fault-free ignition cycles

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Testing

Important: Refer to SIR Service Precautions.

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

• | Steering wheel coil module

• | SDM module

• | Steering wheel coil module 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. Ignition OFF, disconnect the appropriate harness connector at the inflatable restraint steering wheel module.
2. Ignition ON, verify that the appropriate scan tool Driver Airbag Stage 1 or Stage 2 Squib Circuit Resistance parameter is greater than 5.4 ohms at the control circuits.

⇒ | If less than the specified range, test the control circuits for a short to ground. If the circuits test normal, replace the SDM.

3. Connect a fused jumper wire between the appropriate control circuit terminals listed below:

• | Steering wheel module stage 1 terminal 1 X1 and terminal 2 X1

• | Steering wheel module stage 2 terminal 1 X2 and terminal 2 X2

4. Ignition ON, verify that the appropriate scan tool Driver Airbag Stage 1 or Stage 2 Squib Circuit Resistance parameter is less than 1.2 ohms at the control circuits.

⇒ | If greater than the specified range, test the control circuits for a short to voltage or an open/high resistance. If the circuits test normal, replace the SDM.

5. If all circuits test normal, replace the inflatable restraint steering wheel module.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Steering Wheel Inflatable Restraint Module Coil Replacement

• | Steering Wheel Inflatable Restraint Module Replacement

• | SIR/SRS Wiring Repairs

• | Control Module References for SDM replacement, setup, and programming