B0079
DTC B0079 or B0080
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
- 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 05
- Driver Seat Position Sensor Circuit High Voltage or Open
DTC B0079 06
- Driver Seat Position Sensor Circuit Low Voltage or Open
DTC B0079 08
- Driver Seat Position Sensor Circuit Performance-Signal Invalid
DTC B0079 0C
- Driver Seat Position Sensor Circuit Low Current
DTC B0080 01
- Passenger Seat Position Sensor Circuit Short to Battery
DTC B0080 02
- Passenger Seat Position Sensor Circuit Short to Ground
DTC B0080 04
- Passenger Seat Position Sensor Circuit Open
DTC B0080 05
- Passenger Seat Position Sensor Circuit High Voltage or Open
DTC B0080 06
- Passenger Seat Position Sensor Circuit Low Voltage or Open
DTC B0080 08
- Passenger Seat Position Sensor Circuit Performance-Signal Invalid
DTC B0080 0C
- Passenger Seat Position Sensor Circuit Low Current
Diagnostic Fault Information
Circuit/System Description
The seat position sensor is used to determine the proximity of the front driver or passenger seat position with respect to the front air bag. There are two states of seat position, forward and rearward. The seat position sensor interfaces with the inflatable restraint sensing and diagnostic module (SDM) and allows the SDM to disable stage 2 of the air bag for a front seat that is forward of the forward/rearward point in seat track. The seat position sensor provides two current ranges, one range for the forward seat position and one for rearward seat position. When the SDM receives input from a seat position sensor that the seat is rearward, and the SDM will not disable stage 2 deployment. When the seat is forward, the SDM will disable stage 2 deployment. The SDM monitors the seat position sensor circuit and if a fault is detected, the SDM will set code B0079 or B0080 and disable stage 2 frontal deployment.
Conditions for Running the DTC
Ignition voltage is between 9-16 V.
Conditions for Setting the DTC
B0079 01, B0080 01
The SDM detects the seat position sensor signal circuit is shorted to voltage for 2 seconds.
B0079 02, B0080 02
The SDM detects the seat position sensor signal circuit is shorted to ground for 2 seconds.
B0079 04, B0080 04
The SDM detects the seat position sensor signal circuit is open for 2 seconds.
B0079 05, B0080 05
The SDM detects the seat position sensor signal circuit is open or has a high voltage condition for 2 seconds.
B0079 06, B0080 06
The SDM detects the seat position sensor signal circuit is shorted to ground or an open for 2 seconds.
B0079 08, B0080 08
The SDM detects an invalid signal on the seat position sensor signal circuit.
B0079 0C, B0080 0C
The SDM detects a low current condition in the seat position sensor signal circuit for 2 seconds.
Action Taken When the DTC Sets
* The SDM defaults the seat position sensor to seat forward threshold.
* The SDM requests the instrument panel cluster to illuminate the AIR BAG indicator.
Conditions for Clearing the DTC
* The condition for setting the DTC no longer present.
* A history DTC will clear once 100 fault-free ignition cycles have occurred.
Reference Information
Schematic Reference
SIR Schematics (Electrical Diagrams)
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 (Circuit Testing)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)
* Connector Repairs (Connector Repairs)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
1. Verify that DTC B0079 08 or B0080 08 is not set.
• If the DTC is set with the symptom byte 08, replace the appropriate B88 seat position sensor.
2. Ignition ON, observe the scan tool seat position sensor parameter. The reading should be between 2-20 m A. With the scan tool verify that the seat position sensor parameter is between 2-20 m A.
• If not within the specified range, refer to Circuit/System Testing.
3. With the seat un-weighted, observe the scan tool while moving the seat to the full forward and then full rearward positions. The seat position sensor parameter should be continuously between 2-20 m A.
• If not within the specified range, refer to Circuit/System Testing.
4. While sitting in the seat, observe the scan tool while moving the seat to the full forward and then full rearward positions. The seat position sensor parameter should be continuously between 2-20 m A.
• If not within the specified range, refer to Circuit/System Testing.
Circuit/System Testing
Note: 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 module
* Seat position sensor wiring harness connector
* SDM wiring harness connector
1. Ignition OFF, disconnect the harness connector at the appropriate B88 seat position sensor.
2. Test for less than 10 ohm between the 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 K36 SDM.
3. Ignition ON, test for 4-9 V between the signal circuit terminal 2 and ground.
• If less than the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K36 SDM.
• If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K36 SDM.
4. If all circuits test normal, replace the B88 seat position sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Inflatable Restraint Driver or Passenger Seat Position Sensor Replacement (Service and Repair)
* SIR/SRS Wiring Repairs (SIR/SRS Wiring Repairs)
* Control Module References (Programming and Relearning) for SDM replacement, setup, and programming