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P code powertrain High severity

P0887 TCM Power Relay Control Circuit High

The OBD2 code P0887 indicates a problem with the Transmission Control Module (TCM) power relay control circuit, specifically that the circuit is reading a high voltage when it should not be

Definition

The OBD2 code P0887 indicates a problem with the Transmission Control Module (TCM) power relay control circuit, specifically that the circuit is reading a high voltage when it should not be

Common causes

  • Faulty TCM (Transmission Control Module)
  • Bad power relay
  • Open or shorted wiring in the control circuit
  • Poor ground connection
  • Faulty fuse
  • Malfunctioning ignition switch
  • Corroded connectors or terminals

Common misdiagnoses

  • Transmission Control Module (TCM) failure
  • Faulty wiring or connectors
  • Battery or charging system issues
  • Engine Control Module (ECM) problems
  • Transmission fluid issues
  • Faulty power relay
  • Grounding issues
  • Incorrectly diagnosed transmission problems
  • Sensor malfunctions
  • Software or firmware issues in the TCM

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context for the issue

  2. 2. Inspect the TCM Power Relay

  3. 3. Locate the TCM power relay in the fuse box or relay panel

  4. 4. Check for any signs of damage, corrosion, or burnt contacts

  5. 5. If possible, swap the relay with a similar one to see if the problem persists

  6. 6. Examine Wiring and Connectors

  7. 7. Inspect the wiring and connectors associated with the TCM and the power relay for any signs of damage, fraying, or corrosion

  8. 8. Ensure that all connections are secure and free of dirt or moisture

  9. 9. Test the TCM Power Relay

  10. 10. Use a multimeter to test the relay. Check for continuity and ensure that it operates correctly when energized

  11. 11. If the relay is faulty, replace it

  12. 12. Check Power and Ground Supply

  13. 13. Verify that the TCM is receiving the correct voltage and ground. Use a multimeter to check the voltage at the TCM connector

  14. 14. If the voltage is too high or too low, trace the wiring back to the power source and ground to identify any issues

  15. 15. Inspect the TCM

  16. 16. If all other components check out, the TCM itself may be faulty. Look for any signs of damage or overheating

  17. 17. If necessary, consult the vehicle's service manual for specific testing procedures for the TCM

  18. 18. Clear Codes and Test Drive

  19. 19. After performing repairs, clear the trouble codes using the OBD-II scanner

  20. 20. Take the vehicle for a test drive to see if the code returns

  21. 21. Consult a Professional

  22. 22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with transmission issues and can perform more advanced diagnostics. By following these steps, you should be able to identify and resolve the issue related to the P0887 code