Diagnostic Instructions

DTC Descriptors

DTC B0090 00: Rollover Sensor No Additional Information

DTC B0090 0F: Rollover Sensor Erratic

DTC B0090 3A: Rollover Sensor Incorrect Component Installed

DTC B0090 39: Rollover Sensor Internal Electronic Failure

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 Ground	--	B0090 0F	B0090 0F	--	B0090 0F
Roll Over Sensor High Signal	B0090 0F	B0090 0F	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

All of the following conditions must exist for 5 seconds:

B0090 0F

B0090 3A

B0090 39

B0090 71

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

Action Taken When the DTC Sets

Conditions for Clearing the DTC

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

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 in the following requires repair or replacement of the affected component/connector.

•	SDM module

•	Vehicle rollover sensor harness connector

•	SDM wiring harness connector

1. Verify DTC B0090 39 is not set.

⇒	If DTC is set, replace the rollover sensor.

2. Ignition OFF, disconnect the harness connector at the rollover sensor and the SDM.
3. Test for less than 5 ohms between the rollover sensor ground circuit terminal 6 and ground.

⇒	If greater then the specified range, test the circuit for an open/high resistance.

4. Test for less than 5 ohms between the serial data circuit terminal 5 and the SDM occupant sensor serial data circuit terminal 58.

⇒	If greater then the specified range, test the circuit for a short to ground or an open/high resistance.

5. Ignition ON, test for less than 1 volt between the serial data circuit terminal 5 and ground.

⇒	If greater then the specified range, test the circuit for a short to voltage.

6. Verify a test lamp illuminates between the B+ circuit terminal 1 and ground.

⇒	If the test lamp does not illuminate, test the 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.

7. With a scan tool, clear DTCs. Verify DTC B0090 is not set.

⇒	If DTC is set, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.