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 0.5 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 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.

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.

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.

- 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

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.

• If not within the specified range, test the low reference circuit for a short to voltage or 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.

• If less than 4.8 volts, 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 5.2 volts, 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 less than 1.0 ohm between the signal circuit terminal C and ground.

• If not within the specified range, test the signal circuit for a short to ground or an open/high resistance.

6. Test for less than 1.0 volt between the signal circuit terminal C and ground.

• If not within the specified range, test the signal circuit for a short to voltage.

7. Test for less than 1.0 ohm along the signal circuit terminal C to terminal 4.

• If not within 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. Verification Tests

* Seat Belt Retractor Pretensioner Replacement - Front (Sedan)
* SIR/SRS Wiring Repairs