B0079
DTC B0079
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview)provides an overview of each diagnostic category.
DTC Descriptors
DTC B0079 01
- 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 inflatable restraint I/P module. 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 inflatable restraint I/P module. 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 LF seat position sensor signal circuit and if a fault is detected, the SDM will set DTC B0079 and defaults to disabling stage 2 inflatable restraint I/P module deployment.
Conditions for Running the DTC
Ignition voltage is between 9-16 volts.
Conditions for Setting the DTC
B0079 01
The SDM detects the LF seat position sensor signal circuit is shorted to voltage for 500 milliseconds.
B0079 02
The SDM detects the LF seat position sensor signal circuit is shorted to ground for 500 milliseconds.
B0079 04
The SDM detects the LF seat position sensor signal circuit is open for 500 milliseconds.
B0079 06
The SDM detects the LF 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 LF seat position sensor signal circuit.
Action Taken When the DTC Sets
* The SDM defaults the seat position sensor to seat forward threshold.
* The SDM illuminates the AIR BAG warning lamp.
Conditions for Clearing the DTC
* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 255 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 (Connector Views)
Description and Operation
SIR System Description and Operation (Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning)for scan tool information
Circuit/System Verification
Ignition ON, observe the SDM Psgr. 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:
* The seat position sensor
* The SDM
* The seat position sensor wiring harness connector
* The SDM wiring harness connector
1. Ignition OFF, disconnect the harness connector at the LF 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 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 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 seat position sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.
Control Module References (Programming and Relearning)for SDM replacement, setup, and programming