GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0081 0F: Passenger Presence System Erratic

DTC B0081 3A: Passenger Presence System Incorrect Component Installed

DTC B0081 4B: Passenger Presence System Calibration Not Learned

DTC B0081 5A: Passenger Presence System Plausibility Failure

DTC B0081 39: Passenger Presence System Internal Electronic Failure

DTC B0081 71: Passenger Presence System Invalid Serial Data Received

Circuit/System Description

When the ignition is turned ON, the passenger presence system (PPS) and the inflatable restraint sensing and diagnostic module (SDM) performs tests to diagnose critical malfunctions. When the SDM has completed the power-up mode, the SDM will establish communication with the PPS. The SDM will also request the instrument panel cluster (IPC) to illuminate both of the PASSENGER AIR BAG ON/OFF indicators ON for 5 seconds. If the SDM determines the correct PPS is installed and functioning normally, the SDM will illuminate the passenger side airbags ON or OFF based on messages from the PPS. The SDM will also send a message to the IPC to illuminate the appropriate PASSENGER AIR BAG ON/OFF indicator.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

All of the following conditions must exist for 5 seconds:

B0081 0F

The SDM has received a fault present message from the PPS.

B0081 3A

The SDM has received a message from the PPS which indicates a vehicle and PPS mismatch.

B0081 4B

Calibration not learned.

B0081 5A

    • The PPS has lost communications with the SDM.
    • When the enabled state between the PPS and the SDM does not match.
    • After the PPS change states, the SDM signal stating the Passenger Status Data Received is not valid within 2.6 seconds.

B0081 39

The SDM has received a critical malfunction message from the PPS.

B0081 71

The SDM has received invalid or no serial data from the PPS.

Action Taken When the DTC Sets

    • The PPS will set a DTC, and then communicate with the SDM.
    • The SDM disables the Passenger Airbag Module.
    • The PPS will illuminate the Passenger Airbag status OFF indicator.
    • The SDM requests the instrument panel cluster (IPC) to illuminate the AIRBAG indicator.

Conditions for Clearing the DTC

    • The condition for setting the DTC no longer exists and there is no activity on the low speed serial data circuits.
    • A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Diagnostic Aids

If either the SDM or PPS were replaced, verify that the correct part numbers were used for the vehicle application.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

    Important: 

       • When removing connectors inspect for damage, corrosion or poor connection. Damage or corrosion in the following requires repair or replacement of the affected component/connector.
       • PPS module
       • SDM module
       • PPS module harness connector
       • SDM wiring harness connector

  1. Ignition ON, verify no PPS DTCs are set in the PPS or SDM.
  2. If any PPS DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  3. Verify DTC B1000, B1001, or U0170 is not set as current.
  4. If any of the DTCs are set as current, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  5. Verify DTC B0081 3A is not set as current.
  6. If DTC B0081 3A is set as current, replace the PPS with the correct part number.
  7. Verify DTC B0081 5A is not set as current.
  8. If DTC B0081 5A is current, check the SDM for DTC B1001 or a vehicle rollover sensor (ROS) mismatch fault.
  9. Verify DTC B0081 4B is not set as current.
  10. If DTC B0081 4B is current, refer to Passenger Presence System Rezeroing.
  11. Verify DTC B0081 39 is not set as current.
  12. If DTC B0081 39 is set as current, replace the PPS.
  13. Verify DTC B0081 71 or B0081 0F is not set.
  14. If DTC B0081 71 or B0081 0F is set, clear the DTCs. No other repairs are necessary.

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