GM Service Manual Online
For 1990-2009 cars only

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 065: Sensor Circuit Out of Range

Circuit/System Description

The passenger presence system (PPS) uses a silicone filled sensor pad located underneath the passenger seat foam cushion and is connected by a hose clamp to a pressure sensor. The weight of the occupant sitting in the front passenger seat is measured as a pressure change within the bladder by the pressure sensor. The pressure sensor is a 3-wire sensor consisting of a power, ground, and signal circuit. The PPS continually monitors itself and if a fault in this circuit occurs, DTC 065 will 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 PPS sensor signal is less than 0.05 volt or greater than 4.5 volts for 500 milliseconds.
    • The PPS detects the voltage at the PPS 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 PPS 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

DTC 063 is an indication that the PPS is out of calibration or failed a rezero attempt. You cannot recalibrate the PPS. Replace the PPS after following the instructions in the Circuit/System Testing.

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: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

       • The PPS module
       • The SDM module
       • The PPS wiring harness connector
       • The SDM wiring harness connector

  1. Ignition OFF, disconnect the PPS module connector.
  2. Test the PPS 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.
  3. If any of the above conditions are found make the appropriate repair.
  4. Test the PPS 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.
  5. If any of the above conditions are found make the appropriate repair.
  6. Test the PPS 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.
  7. If any of the above conditions are found make the appropriate repair
  8. Ignition ON, engine OFF test the PPS sensor signal circuit with a DMM. Measure the voltage of the PPS sensor circuit harness side and ground. The voltage should read 0.5-4.5 volts.
  9. If the voltage is more than 5 volts test the PPS sensor signal circuit for a short to voltage. If the circuit tests good replace the PPS.
  10. Reconnect all PPS components. Use the scan tool to clear all PPS DTCs. Refer to Passenger Presence System Flash Code Procedures . Verify DTC 065 does not exist.
  11. If DTC 065 reset replaced the PPS.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  SIR/SRS Wiring Repairs
    •  Control Module References for PPS replacement, setup, and programming