U2973 Lost Communication with the Steering Angle Sensor
The OBD2 code U2973 indicates a loss of communication with the steering angle sensor, which may affect the vehicle's stability control and steering systems
Definition
Common causes
- Faulty steering angle sensor
- Damaged wiring or connectors
- Poor electrical connections
- Malfunctioning vehicle control module
- Software issues or bugs
- Corrosion in connectors or terminals
- Interference from other electronic components
- Low battery voltage or power supply issues
Common misdiagnoses
- Faulty steering angle sensor
- Wiring issues or damaged connectors
- Faulty steering column module
- ABS module failure
- Power steering system issues
- Incorrectly calibrated steering angle sensor
- Faulty body control module (BCM)
- Software or firmware issues in the vehicle's control modules
Troubleshooting steps
-
1. 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
-
2. 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
-
3. Connector Pins
Ensure that the pins in the connectors are not bent, corroded, or pushed back
-
4. Test the Steering Angle Sensor
Sensor Functionality: If possible, test the steering angle sensor using a multimeter or scan tool to ensure it is functioning correctly. Check for proper voltage and resistance values as specified in the vehicle’s service manual
-
5. Calibration
Some vehicles require the steering angle sensor to be calibrated after installation or repair. Check if calibration is necessary
-
6. Check Power and Ground
Verify that the steering angle sensor is receiving the correct voltage and has a good ground connection. Use a multimeter to measure voltage at the sensor connector
-
7. Inspect the CAN Bus
Since the steering angle sensor communicates over the CAN bus, check for issues with the CAN network. Look for
-
8. Open circuits or shorts in the CAN wiring
-
9. Other modules on the CAN bus that may be malfunctioning and affecting communication
-
10. Scan Tool Data
Use a scan tool to monitor live data from the steering angle sensor. Look for any irregularities in the readings when turning the steering wheel
-
11. Check for Software Updates
Sometimes, manufacturers release software updates that can resolve communication issues. Check if there are any updates available for the vehicle’s ECU
-
12. Inspect Related Components
Check other components that may be related to the steering system, such as the steering column, power steering pump, or electronic stability control (ESC) system, as issues in these areas can affect the steering angle sensor
-
13. Clear Codes and Test Drive
After performing the above checks and repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns
-
14. Professional Help
If you are unable to resolve the issue after these steps, consider seeking help from a professional mechanic or dealership, as they may have specialized tools and knowledge for diagnosing complex issues. By following these steps, you should be able to identify the cause of the U2973 code and take appropriate action to resolve it