GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2006 🢒 XLR 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 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

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 by illuminating either the ON or OFF indicator on the PASSENGER AIR BAG ON/OFF indicators. Then the PPS will communicate to the sensing and diagnostic module (SDM) through a non-class 2 communications circuit that a PPS fault is present. The SDM will then set DTC B0092 indicating a problem within the PPS and will suppress the deployment of the instrument panel (I/P) module and then request the instrument panel cluster (IPC) to illuminate the AIR BAG 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 B0092.
    • The SDM disables the I/P module deployment loop.
    • The PPS will turn ON the passenger air bag status OFF indicator.
    • The SDM commands the AIR BAG indicator ON via serial data communication.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used.
    • A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

Diagnostic Aids

Inspect the passenger seat belt tension retractor sensor signal, 5-volt reference, and low reference circuits carefully for cutting and/or chafing.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

SIR Connector End Views

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 Replacement - Right Front with the seat belt tension retractor sensor must be serviced as a complete unit.

When removing the connectors inspect for damage or corrosion. Damage or corrosion to 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 ON, test for 4.5-5.5 volts between the voltage reference circuit terminal A and ground.
    3. ⇒If less that the specified range, test the voltage reference circuit for an open/high resistance or a short to ground. If the circuit tests normal, replace the PPS module.
    ⇒If greater that the specified range, test the voltage reference circuit for a short to voltage. If the circuit tests normal, replace the PPS module.

    Important: The SCMPSIR SW fuse that supplies ignition voltage must be removed to ensure the PPS module is inactive. An active PPS module may cause inaccurate resistance readings.

  3. Ignition OFF, remove the SCMPSIR fuse. Test for less than 2 ohms between low reference terminal B and ground.
    4. ⇒If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the PPS module.
  4. Ignition OFF, disconnect the harness connector at the PPS module.
  5. Test for infinite resistance between the signal circuit terminal C and ground.
    6. ⇒If less than the specified value, test the signal circuit for a short to ground.
  6. Ignition ON, test for less than 1 volt between the signal circuit terminal C and ground.
    7. ⇒If greater than the specified range, test the signal circuit for a short to voltage.
  7. Test for less than 1 ohm between the signal circuit terminal C at the sensor harness connector and terminal 4 at the PPS module harness connector.
    8. ⇒If greater than the specified range, test the signal circuit for an open/high resistance.
  8. If all circuits test normal, replace the seat belt tension sensor.
  9. Reconnect all PPS components. Clear all PPS DTCs. Refer to Passenger Presence System Flash Code Procedures . Rezero the PPS, refer to Passenger Presence System Rezeroing . Verify DTC 023 does not exist.
    10. ⇒If DTC 023 is set, replaced the PPS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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