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U code network High severity

U0420 Invalid Data Received From Power Steering Control Module

The OBD2 code U0420 indicates that the vehicle's control module has received invalid or corrupted data from the power steering control module

Definition

The OBD2 code U0420 indicates that the vehicle's control module has received invalid or corrupted data from the power steering control module

Common causes

  • Faulty power steering control module
  • Wiring issues (shorts, opens, or corrosion)
  • Poor connections or loose connectors
  • Software glitches or outdated firmware
  • Faulty vehicle control module (VCM)
  • Malfunctioning sensors related to power steering
  • Electrical interference or noise in the system
  • Low power supply voltage to the power steering module

Common misdiagnoses

  • Faulty Power Steering Control Module
  • Wiring issues or short circuits
  • Faulty steering angle sensor
  • Faulty vehicle speed sensor
  • Issues with the engine control module (ECM)
  • Problems with the body control module (BCM)
  • Incorrectly calibrated steering system
  • Low power steering fluid levels
  • Faulty connectors or terminals
  • Other communication errors in the CAN bus system

Troubleshooting steps

  1. 1. Check for Additional Codes

  2. 2. Use an OBD-II scanner to check for any other related trouble codes. This can provide more context and help identify if there are other issues affecting the power steering system

  3. 3. Inspect Wiring and Connectors

  4. 4. Visually inspect the wiring and connectors related to the power steering control module. Look for signs of damage, corrosion, loose connections, or frayed wires that could cause communication issues

  5. 5. Check Power and Ground

  6. 6. Ensure that the power steering control module is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the module's power and ground pins

  7. 7. Test the Power Steering Control Module

  8. 8. If the wiring and connections are intact, the power steering control module itself may be faulty. Testing or replacing the module may be necessary. Consult the vehicle's service manual for specific testing procedures

  9. 9. Inspect the Steering Angle Sensor

  10. 10. The steering angle sensor can affect the power steering system's performance. Check for proper operation and calibration of the sensor, as it may send incorrect data to the control module

  11. 11. Check for Software Updates

  12. 12. Sometimes, manufacturers release software updates for the control modules. Check if there are any updates available for the power steering control module that may resolve communication issues

  13. 13. Clear Codes and Test Drive

  14. 14. After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner. Take the vehicle for a test drive to see if the code reappears

  15. 15. Consult Technical Service Bulletins (TSBs)

  16. 16. Look for any TSBs related to the power steering system for your specific vehicle make and model. Manufacturers may have identified common issues and provided solutions

  17. 17. Professional Diagnosis

  18. 18. If the issue persists after performing the above steps, it may be necessary to seek help from a professional mechanic or dealership. They have specialized tools and knowledge to diagnose complex issues. By following these steps, you can systematically identify and resolve the issue related to the U0420 code