B0079
DTC B0079
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 B0079 01
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Driver Seat Position Sensor Circuit Short to Battery
DTC B0079 02
-
Driver Seat Position Sensor Circuit Short to Ground
DTC B0079 04
-
Driver Seat Position Sensor Circuit Open
DTC B0079 06
-
Driver Seat Position Sensor Circuit Short to Ground or Open Circuit
DTC B0079 08
-
Driver Seat Position Sensor Circuit Signal Invalid
Diagnostic Fault Information
Circuit/System Description
The seat position sensor is used to determine the proximity of a front driver seat position with respect to the driver steering wheel air bag. The seat position sensor is a hall effect sensor that is mounted on the seat track of the front driver seat. The seat position sensor is connected to the sensing and diagnostic module (SDM) with a low reference and a signal circuit. The SDM uses the state of the seat position sensor to determine the need for a stage 2 deployment of the driver steering wheel air bag. When the seat is in the forward position stage 2 deployment is disabled, and when in the rearward position stage 2 deployment is enabled. The SDM monitors the driver seat position sensor signal circuit and if a fault is detected, the SDM will set DTC B0079 and defaults to disabling stage 2 driver steering wheel air bag deployment.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
B0079 01
The SDM detects the driver seat position sensor signal circuit is shorted to voltage for 500 milliseconds.
B0079 02
The SDM detects the driver seat position sensor signal circuit is shorted to ground for 500 milliseconds.
B0079 04
The SDM detects the driver seat position sensor signal circuit is open for 500 milliseconds.
B0079 06
The SDM detects the driver seat position sensor signal circuit is shorted to ground or an open for 500 milliseconds.
B0079 08
The SDM detects an invalid signal on the driver seat position sensor signal circuit.
Action Taken When the DTC Sets
* The SDM defaults the seat position sensor to seat forward threshold.
* The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
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 A/C Compressor Clutch
Description and Operation
SIR System Description and Operation SIR System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Ignition ON, observe the SDM Driver Seat Position Sensor parameter while moving the driver seat fully forward and fully rearward. The parameter should cycle between Forward to Rearward as the seat is moved in the respective direction and DTC B0079 should not set.
If the parameters are correct and DTC B0079 is set, replace the SDM.
Circuit/System Testing
Important:
When removing connectors, inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector:
* Seat position sensor
* SDM
* Seat position sensor wiring harness connector
* SDM wiring harness connector
1. Ignition OFF, disconnect the harness connector at the driver seat position sensor.
2. Test for less than 10 ohms between low reference circuit terminal 1 and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the SDM.
3. Ignition ON, test for 4.5-5.5 volts between the signal circuit terminal 2 and ground.
• If less that the specified range, test the signal circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the SDM.
• If greater that the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the SDM.
4. If the circuits test normal, test or replace the driver seat position sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
Refer to Driver Seat Position Sensor replacement
Control Module References Control Module References for SDM replacement, setup, and programming