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 0F: Rollover Sensor Erratic

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

Ignition 1

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 ignition 1 voltage 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 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. For 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 either the SDM or vehicle rollover sensor were 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: Refer to SIR Service Precautions.

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in 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. Ignition OFF, disconnect the harness connector at the rollover sensor and the SDM.
  2. Test for less than 5 ohms between the rollover sensor ground circuit terminal 6 and ground.
  3. If greater then the specified range, test the ground circuit for an open/high resistance.
  4. Test for greater then 5 ohms between the rollover sensor serial data circuit terminal 5 and ground.
  5. If less than the specified range, test the serial data circuit for a short to ground.
  6. Ignition ON, test for less than 1 volt between the rollover sensor serial data circuit terminal 5 and ground.
  7. If greater then the specified range, test the serial data circuit for a short to voltage.
  8. Test for less than 5 ohms between the rollover sensor serial data circuit terminal 5 and the SDM occupant sensor serial data circuit terminal 60.
  9. If greater then the specified range, test the serial data circuit for an open/high resistance.
  10. Verify that a test lamp illuminates between the ignition 1 circuit terminal 1 and ground.
  11. If the test lamp does not illuminate, test the ignition circuit for an open/high resistance. If the circuit fuse is open, test the circuit for a short to ground, if the circuit tests normal, replace the rollover sensor.
  12. With a scan tool, clear DTCs. Verify DTC B0090 is not set.
  13. If the DTC is set, 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