U2977 – Lost Communication with the Steering Angle Sensor.

The ODBII code U2977 indicates a loss of communication with the steering angle sensor, which may affect the vehicle’s stability control and steering systems.

The severity of ODBII code U2977 is generally considered moderate.

Common Causes For: U2976 Lost Communication with the Steering Angle Sensor.

• Faulty steering angle sensor
• Damaged wiring or connectors
• Poor electrical connections
• Malfunctioning vehicle control module
• Software issues or updates needed
• Corrosion or dirt in connectors
• Power supply issues to the sensor
• Faulty CAN bus communication

Common misdiagnosis for U2977 Lost Communication with the Steering Angle Sensor.

• Faulty steering angle sensor
• Wiring issues or damaged connectors
• Faulty ABS module
• Faulty power steering control module
• Incorrectly calibrated steering angle sensor
• Software or firmware issues in the vehicle’s control modules
• Battery or power supply issues affecting sensor operation

Common Troubleshooting Steps

When dealing with OBD-II code U2977, which indicates “Lost Communication with the Steering Angle Sensor,” there are several common troubleshooting steps you can take to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Sometimes, related codes can provide more context for the issue.
• Inspect Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors associated with the steering angle sensor for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or damaged.
• Test the Steering Angle Sensor: **Sensor Functionality: If possible, test the steering angle sensor using a multimeter or an oscilloscope to ensure it is functioning correctly.
• **Calibration: Some vehicles require the steering angle sensor to be calibrated after installation or repair. Check the vehicle’s service manual for calibration procedures.
• Check Power and Ground: **Power Supply: Verify that the steering angle sensor is receiving the correct voltage. Use a multimeter to check the power supply at the sensor connector.
• **Ground Connection: Ensure that the ground connection for the sensor is intact and providing a good ground.
• Inspect the CAN Bus: **Communication Lines: Since the steering angle sensor communicates over the CAN bus, check for any issues with the CAN wiring. Look for shorts, opens, or interference.
• **CAN Bus Termination: Ensure that the CAN bus is properly terminated at both ends.
• Check for Software Issues: **ECU Updates: Sometimes, the issue can be resolved by updating the vehicle’s ECU software. Check with the manufacturer for any available updates.
• **Resetting the System: Clear the trouble codes and see if the code returns after a test drive. This can sometimes reset communication issues.
• Inspect Related Components: **Steering Column: Check for any issues with the steering column or related components that may affect the sensor’s operation.
• **Other Sensors: Inspect other sensors that may be related to the steering system, such as the yaw rate sensor or ABS sensors.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the steering angle sensor or communication issues for your specific vehicle make and model. Manufacturers often release TSBs for known issues.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized diagnostic tools and experience with your specific vehicle.Conclusion By following these troubleshooting steps, you can systematically identify and resolve the issue related to the U2977 code. Always refer to the vehicle’s service manual for specific procedures and specifications related to your vehicle model.