U2139 – Lost Communication with the Steering Angle Sensor Module.

The ODBII code U2139 indicates that there is a loss of communication with the Steering Angle Sensor Module, which may affect the vehicle’s stability control and steering functions.

The severity of ODBII code U2139 is generally considered moderate.

Common Causes For: U2138 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
• Low battery voltage or power supply issues
• Corrosion or dirt in connectors
• Faulty CAN bus communication
• Intermittent faults in the sensor or wiring

Common misdiagnosis for U2139 Lost Communication with the Steering Angle Sensor Module.

• Faulty Steering Angle Sensor
• Wiring or connector issues
• Faulty Body Control Module (BCM)
• Faulty Electronic Power Steering (EPS) module
• Incorrectly calibrated steering angle sensor
• Faulty ABS module
• Software or firmware issues in the vehicle’s control modules
• Battery or charging system problems

Common Troubleshooting Steps

When dealing with the OBD-II code U2139, which indicates “Lost Communication with the Steering Angle Sensor Module,” there are several common troubleshooting steps you can follow 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, multiple codes can provide more context for the issue.
• Inspect Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors related to 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 pushed back.
• Test the Steering Angle Sensor: **Sensor Functionality: If possible, test the steering angle sensor to ensure it is functioning correctly. This may involve using a multimeter or an oscilloscope to check the output signals.
• **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: **Updates: Check if there are any software updates available for the vehicle’s ECU that may address communication issues.
• **Resetting the ECU: Sometimes, resetting the ECU by disconnecting the battery for a few minutes can clear temporary communication faults.
• Inspect Related Modules: **Other Modules: Check if other modules that communicate with the steering angle sensor are functioning properly. A fault in another module can sometimes cause communication issues.
• Perform a System Scan: Use a professional-grade scan tool to perform a complete system scan. This can help identify any hidden issues or communication problems between modules.
• 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 may have known fixes for common problems.
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these troubleshooting steps, you should be able to identify the root cause of the U2139 code and take appropriate action to resolve the issue.