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P code powertrain Medium severity

P2602 Coolant Pump "A" Control Circuit Low

The OBD2 code P2602 indicates that there is a low voltage or an open circuit in the control circuit for the coolant pump "A," which may affect the operation of the coolant pump

Definition

The OBD2 code P2602 indicates that there is a low voltage or an open circuit in the control circuit for the coolant pump "A," which may affect the operation of the coolant pump

Common causes

  • Faulty coolant pump
  • Damaged wiring or connectors
  • Short circuit in the control circuit
  • Open circuit in the control circuit
  • Faulty engine control module (ECM)
  • Blown fuse
  • Corroded connectors

Common misdiagnoses

  • Faulty coolant pump
  • Wiring issues or shorts in the circuit
  • Bad relay
  • Faulty engine control module (ECM)
  • Low coolant level
  • Thermostat malfunction
  • Sensor issues (e.g., temperature sensor)
  • Electrical connector problems

Troubleshooting steps

  1. 1. Check the Code

    Use an OBD-II scanner to confirm that the P2602 code is present. Check for any additional codes that may provide more context about the issue

  2. 2. Inspect the Coolant Pump

  3. 3. Locate the coolant pump and visually inspect it for any signs of damage, corrosion, or leaks

  4. 4. Ensure that the pump is securely mounted and that all connections are intact

  5. 5. Check the Wiring and Connectors

  6. 6. Inspect the wiring harness and connectors leading to the coolant pump for any signs of wear, fraying, or damage

  7. 7. Look for loose or corroded connections that could affect the circuit

  8. 8. Test the Coolant Pump

  9. 9. If possible, test the coolant pump directly by applying power to it to see if it operates. If it does not run, the pump may be faulty and need replacement

  10. 10. Measure the resistance of the pump motor using a multimeter. Compare the readings to the manufacturer's specifications

  11. 11. Check the Control Circuit

  12. 12. Use a multimeter to check the voltage at the coolant pump connector while the engine is running. You should see a voltage reading that indicates the pump is receiving power

  13. 13. If the voltage is low or absent, trace the wiring back to the control module to identify any breaks or shorts in the circuit

  14. 14. Inspect the Engine Control Module (ECM)

  15. 15. If the wiring and pump are in good condition, the issue may lie with the ECM. Check for any software updates or recalls related to the coolant pump control

  16. 16. If necessary, perform a reset of the ECM by disconnecting the battery for a few minutes

  17. 17. Check for Ground Issues

  18. 18. Ensure that the coolant pump has a good ground connection. A poor ground can lead to low voltage readings and cause the pump to malfunction

  19. 19. Look for Related Issues

  20. 20. Check the vehicle's cooling system for any other issues that may affect the coolant pump's operation, such as low coolant levels or a malfunctioning thermostat

  21. 21. Clear the Codes and Test Drive

  22. 22. After performing the necessary repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  23. 23. Consult a Professional

  24. 24. If you are unable to resolve the issue after these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P2602 code