For 1990-2009 cars

### 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 B1011 71: System Disabled Information Stored Invalid Serial Data Received

### Circuit/System Description

The vehicle rollover sensor (ROS) monitors the vehicle speed signal (VSS) on the GMLAN serial data circuit. If the VSS is marked as invalid or is missing, the ROS will set a diagnostic trouble code (DTC).

### Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

### Conditions for Setting the DTC

If the VSS is marked as invalid or is missing.

### 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

DTC B1011 does not indicate a ROS system malfunction and will not cause any warning indicators to illuminate. Factors such as a long engine crank or a delay in serial data communications will cause B1011 to set.

### Reference Information

#### Electrical Information Reference

• | Circuit Testing

• | Testing for Intermittent Conditions and Poor Connections

• | Connector Repairs

• | Wiring Repairs

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

SIR/SRS Wiring Repairs