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.

Upon passing these tests, 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 deployment loops.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1379 LF Side Deployment Loop Resistance Low

### Conditions for Running the DTC

Ignition voltage is within the normal operating voltage range.

### Conditions for Setting the DTC

• | The resistance of the driver air bag deployment loop is lower than 1.4 ohms.

• | The shorting bar is damaged and the SDM must be replaced.

### 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: SIR Connector End Views
1 | Did you perform a Diagnostic System Check - Vehicle? |  | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Confirm the ignition switch is OFF.
2. Disconnect the connector of the driver side impact module.
3. Disconnect the connector of the sensing and diagnostic module (SDM) wiring.
4. Measure the resistance between terminal 1 and 2 of the driver side impact module wiring harness.

Is the resistance equal to the specified value?

∞

Go to Step 3

Go to Step 5

3 |

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 6

Go to Step 4

4 | Replace the driver side impact module. Is the replacement complete? | -- | Go to Step 6 | --
5 | Replace the air bag wiring. Is the replacement complete? | -- | Go to Step 6 | --
6 |

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