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 Descriptors

DTC B0090 00: Rollover Sensor

DTC B0090 0F: Rollover Sensor Erratic

DTC B0090 39: Rollover Sensor Internal Electronic Failure

DTC B0090 3A: Rollover Sensor Incorrect Component Installed

DTC B0090 71: Rollover Sensor Invalid Serial Data Received

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Battery Positive Voltage

B0090 0F

B0090 0F

B0090 0F

--

B0090 0F

Roll Over Sensor Signal

B0090 0F

B0090 0F

B0090 0F

B0090 0F

B0090 0F

Roll Over Sensor Ground

--

B0090 0F

B0090 0F

--

B0090 0F

Circuit/System Description

The inflatable restraint vehicle rollover sensor (ROS) utilizes battery power supply and a bidirectional interface circuit. The ROS modulates current on the interface to send ID, State of Health, and deployment commands to the inflatable restraint sensing and diagnostic module (SDM). When the ignition is turned on the ROS responds by performing internal diagnostics and sending an ID to the SDM. The ROS continually communicates status messages to the SDM, which determines if a fault is present in the ROS circuit. If the fault is present, the SDM will set a diagnostic trouble code (DTC).

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

Any of the following conditions must exist for 5 seconds:

B0090 0F

    • The SDM received a fault present message from the ROS.
    • The ROS is in assembly plant mode and the SDM is in production mode.
    • The SDM has not received any data from the ROS.

B0090 39

    • The SDM has received a Not Ok (NOK) message from the vehicle rollover sensor.
    • The SDM has not received a message.

B0090 3A

    • The SDM has received an ID message from the vehicle rollover sensor which does not match the ID stored in the SDM memory.
    • The SDM has reset the vehicle rollover sensor twice without detecting the correct ID message.

B0090 71

The SDM has received invalid serial data from the vehicle rollover sensor.

Action Taken When the DTC Sets

    • The SDM requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
    • The side air bag deployment loops will be disabled for rollover events only, however side impact events the side air bags are still enabled.

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

If the SDM or ROS have been replaced, verify that the correct part numbers were used for the vehicle application and the components were properly configured. Refer to Control Module References for SDM and ROS setup and programming.

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 Testing

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

   • Vehicle rollover sensor
   • SDM module
   • Vehicle rollover sensor harness connector
   • SDM wiring harness connector

  1. Verify DTC B0090 39 or B0090 71 is not set.
  2. If either DTC is set, replace the rollover sensor.
  3. Verify DTC B0090 3A is not set.
  4. If the DTC is set, verify the correct part number ROS is installed in the vehicle. If the installed ROS is incorrect, replace the ROS.
  5. Ignition OFF, disconnect the harness connector at the ROS.
  6. Test for less than 5 ohms between the ground circuit terminal 6 and ground.
  7. If greater than the specified range, test the ground circuit for an open/high resistance.
  8. Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 1 and ground.
  9. If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
  10. Test for less than 1 volt between the signal circuit terminal 5 and ground.
  11. If greater than the specified range, test the signal circuit for a short to voltage.
  12. Ignition OFF, disconnect the harness connector at the SDM.
  13. Test for less than 5 ohms between the signal circuit terminal 5 at the ROS harness connector and the signal circuit terminal 58 at the SDM harness connector.
  14. If greater than the specified range, test the signal circuit for an open/high resistance.
  15. Ignition ON, test for less than 1 volt between the signal circuit terminal 5 at the ROS harness connector and B+.
  16. If greater than the specified range, test the signal circuit for a short to ground.
  17. If all circuits test normal, replace the ROS.
  18. Reconnect all SIR components. Ignition ON, verify the DTC is not set as current.
  19. If the DTC resets as current, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inflatable Restraint Vehicle Rollover Sensor Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM and ROS replacement, setup, and programming