For 1990-2009 cars

### Circuit Description

When the ignition switch is turned to ON, the sensing and diagnostic module (SDM) will perform a turn-on test to diagnose critical malfunctions within the SDM itself.

These test ignition and deployment loop voltages are measured to ensure that they are within their normal voltage ranges. The SDM monitors the voltages at the driver low and the passenger low to detect shorts to ground or voltage in the deploy loops.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1349 Driver Frontal Deployment Loop Stage 1 Short to Battery

### Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

### Conditions for Setting the DTC

• | The air bag wiring of the 1st stage driver high is shorted to battery wiring.

• | The air bag wiring of the 1st stage driver low is shorted to battery wiring.

### Action Taken When the DTC Sets

The SDM commands the AIR BAG indicator ON.

### Conditions for Clearing the DTC

The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.

Step | Action | Values | Yes | No
--- | --- | --- | --- | ---
Caution: Refer to Sensing and Diagnostic Module Handling Caution in the Preface section. Caution: Refer to Sensing and Diagnostic Module Voltage after Ignition is Turned Off Caution in the Preface section. Schematic Reference: SIR Schematics Connector End View Reference: Component Connector End Views
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Confirm the ignition switch is OFF and the sensing and diagnostic module (SDM) fuse has been removed.
2. Wait for 1 minute to discharge the SDM charger.

Has the SDM discharged?

--

Go to Step 3

--

3 | Visually inspect the connector and the wiring of driver air bag. Is the air bag wiring damaged? | -- | Go to Step 7 | Go to Step 4
4 |

1. Confirm the ignition switch is OFF.
2. Remove the steering wheel module.
3. Disconnect the connector of the SDM wiring.
4. Measure the resistance between the high, low wiring of the first stage steering wheel module and the battery.

Is the resistance equal to the specified value?

∞

Go to Step 5

Go to Step 6

5 |

1. Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
2. Confirm the ignition switch is ON.
3. Erase the DTC using the scan tool.
4. Perform the Diagnostic System Check - Vehicle .

Is the DTC removed?

--

Go to Step 10

Go to Step 9

6 |

1. Remove the connector from the steering wheel module coil wiring.
2. Measure the resistance between the high, low wiring of the 1st stage steering wheel module coil and the battery.

Is the resistance equal to the specified value?

∞

Go to Step 8

Go to Step 7

7 | Replace the air bag wiring. Is the replacement complete? | -- | Go to Step 10 | --
8 | Replace the steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement . Is the replacement complete? | -- | Go to Step 10 | --
9 | Replace the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement . Is the replacement complete? | -- | Go to Step 10 | --
10 |

1. Reconnect all SIR components.
2. Verify that all components, connectors and connector position assurances (CPAs) are properly mounted.
3. Use the scan tool in order to clear the DTCs.
4. 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