DTC 023

DTC 023

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview
* 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 of the enable/disable status by turning ON 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 non GMLAN 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 turn the AIR BAG indicator ON.

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 0.05 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 via non GMLAN circuit.
* The SDM will set DTC B0081.
* 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 GMLAN serial data.

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.

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.

1. Important:

* The seat belt retractor pretensioner - RF

* The PPS module

* The SDM module

* The seat belt retractor pretensioner - RF wiring harness connector

* The PPS wiring harness connector

* The SDM wiring harness connector

Ignition OFF, disconnect the seat belt tension retractor sensor. Refer to seat belt retractor replacement - right front in Repair Instructions for location of connector.
2. Disconnect the PPS module connector.
3. Test the seat belt tension retractor sensor signal circuit for a short to ground, a high resistance, or an open. Verify that a short to ground, a high resistance, or an open does not exist.

• If any of the above conditions are found make the appropriate repair.

4. Test the seat belt tension retractor sensor 5-volt reference circuit for a short to ground, a short to voltage, a high resistance, or an open. Verify that a short to ground, a short to voltage, a high resistance, or an open does not exist.

• If any of the above conditions are found make the appropriate repair.

5. Test the seat belt tension retractor sensor low reference circuit for a short to ground, a short to voltage, a high resistance, or an open. Verify that a short to ground, a short to voltage, a high resistance, or an open does not exist.

• If any of the above conditions are found make the appropriate repair

6. Ignition ON, engine OFF test the seat belt tension retractor sensor circuit with a DMM. Measure the voltage of the seat belt tension retractor sensor circuit harness side and ground. The voltage should read 0.05-4.5 volts.

• If the voltage is more than 5 volts test the seat belt tension retractor sensor circuit for a short to voltage. If the circuit tests good replace the PPS.

7. Reconnect all PPS components. Use the scan tool to 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. Component Tests and General Diagnostics Programming and Relearning

• If DTC 023 reset replaced the PPS.

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 Verification Tests