GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Cobalt 🢒 DTC 🢒 DTC 023

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC 023: Seat Belt Tension Sensor Circuit Out of Range

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

5-Volt Reference

023

023

023

--

Seat Belt Tension Sensor Signal

023

023

023

--

Low Reference

--

023

--

--

Circuit/System Description

The inflatable restraint seat belt tension sensor is a 3-wire potentiometer mounted on the retractor or buckle side of the seat belt and provides an input to the passenger presence system (PPS). When an infant car seat is properly restrained on the front passenger seat, the seat belt is tightly secured through the car seat. The seat belt pulls on the tension sensor and changes the voltage signal to the PPS module. The PPS monitors the seat belt tension sensor circuit and if a fault is detected, DTC 023 will be set. When the PPS detects this DTC within the PPS, it will notify the customer of the enable/disable status by illuminating the OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. Then the PPS will communicate to the sensing and diagnostic module (SDM) through a serial data communications circuit that a PPS fault is present. The SDM will then set DTC B0081 indicating a problem within the PPS and will suppress the deployment of the instrument panel (I/P) module and then illuminate the AIR BAG warning indicator.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC
    • The PPS detects the voltage at the passenger seat belt tension retractor sensor signal is less than 0.5 volt or greater than 4.5 volts for 500 milliseconds.
    • The PPS detects the voltage at the passenger seat belt tension retractor sensor 5-volt reference is less than 4.5 volts or greater than 9.1 volts for 500 milliseconds.
    • The PPS detects the amperage at the passenger seat belt tension retractor sensor low reference is 25 mA or greater for 500 milliseconds.

Action Taken When the DTC Sets
    • The PPS will set a DTC, and then communicate with the SDM.
    • The SDM will set DTC B0081.
    • The SDM disables the I/P module deployment loop.
    • The PPS will illuminate the passenger AIR BAG status OFF indicator.
    • The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG warning 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

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing

Important: The seat belt tension retractor sensor is not service separately. The Seat Belt Retractor Pretensioner Replacement - Right Front with the seat belt tension retractor sensor must be serviced as a complete unit. When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

   • Seat belt retractor pretensioner - RF
   • PPS module
   • SDM module
   • Seat belt retractor pretensioner - RF wiring harness connector
   • PPS wiring harness connector
   • SDM wiring harness connector

  1. Ignition OFF, disconnect the harness connector at the inflatable restraint passenger seat belt tension sensor.
  2. Ignition OFF, test for less than 1.0 ohm between the low reference circuit terminal B and ground.
    3. ⇒If not within the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PPS.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal A and ground.
    4. ⇒If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the PPS module.
    ⇒If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the PPS module.
  4. Ignition OFF, disconnect the harness connector at the PPS module.
  5. Ignition OFF, test for infinite resistance between the signal circuit terminal C and ground.
    6. ⇒If not the specified value, test the signal circuit for a short to ground.
  6. Ignition ON, test for less than 1.0 volt between the signal circuit terminal C and ground.
    7. ⇒If not within the specified range, test the signal circuit for a short to voltage.
  7. Test for less than 1.0 ohm between the signal circuit terminal C at the sensor harness connector and terminal 4 at the PPS harness connector.
    8. ⇒If greater than the specified range, test the signal circuit for an open/high resistance.
  8. If all circuits test normal, test or replace the inflatable restraint passenger seat belt tension sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Seat Belt Retractor Pretensioner Replacement - Front
    •  SIR/SRS Wiring Repairs
    •  Control Module References for PPS replacement, setup, and programming