Diagnostic Instructions
DTC Descriptor
DTC 023: Seat Belt Tension Sensor Circuit Out of Range
Circuit/System Description
The inflatable restraint seat belt tension sensor is used to enhance the passenger presence system (PPS) when an infant car seat is properly restrained on the front outboard passenger seat. The seat belt tension sensor is a 3-wire potentiometer mounted
on the lower seat belt anchor and provides an input to the PPS module. When an infant car seat is properly restrained on the front passenger seat, the seat belt is tightly secured through the infant car seat. The seat belt pulls on the tension sensor and changes
the voltage signal to the PPS module. The PPS module uses the voltage signal to help determine if a tightly belted infant car seat is installed. The PPS uses the inputs from the seat belt tension sensor and the PPS pressure sensor to determine if the instrument
panel (I/P) module should be suppressed or enabled. The PPS monitors the seat belt tension sensor circuits and sets DTC 023 if a fault is detected.
Conditions for Running the DTC
Ignition 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | The PPS detects the voltage at the passenger seat belt tension 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 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 sensor low reference is 25 mA or greater for 500 milliseconds. |
Action Taken When the DTC Sets
| • | The SDM disables the instrument panel (I/P) module deployment loop. |
| • | The SDM commands the AIR BAG indicator ON via class 2 serial data. |
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | The scan tool CLEAR DTC command has been issued. |
| • | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the passenger seat belt tension sensor signal, 5-volt reference, and low reference circuits |
| • | An open or high resistance between the passenger seat belt tension sensor signal, 5-volt reference, and low reference circuits |
| • | Inspect the passenger seat belt tension 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/System Testing
- Ignition OFF. Inspect the PPS and seat belt tension sensor connectors for corrosion or damage.
| ⇒ | If the seat belt tension sensor terminals are damaged, replace the seat belt tension sensor. |
| ⇒ | If any of the above conditions are found, make the appropriate repair. |
- Test the seat belt tension sensor signal and voltage circuits for a short to voltage, short to ground or an open/high resistance.
| ⇒ | If any of the above conditions are found, make the appropriate repair. |
- Ignition ON. Test the seat belt tension sensor 5-volt reference circuit for voltage.
| ⇒ | If the sensor reference voltage is not 5 volts, replace the PPS. |
- Test the seat belt tension sensor signal circuit for voltage.
| ⇒ | If the signal circuit voltage is not 0.05-4.5 volts, replace the seat belt tension sensor. |
- Ignition ON. Reconnect all components and with the scan tool clear DTC.
- If DTC 023 does set as a current DTC, replace and rezero the PPS.
| ⇒ | After replacement and rezeroing of the PPS are completed, perform the repair verification. |
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
