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P2059 Reductant Injection Air Pump Control Circuit/Open

The OBD2 code P2059 indicates a malfunction in the reductant injection air pump control circuit, specifically that the circuit is open, meaning there is a break or fault preventing proper operation of the air pump used...

Definition

The OBD2 code P2059 indicates a malfunction in the reductant injection air pump control circuit, specifically that the circuit is open, meaning there is a break or fault preventing proper operation of the air pump used in the exhaust aftertreatment system

Common causes

  • Faulty reductant injection air pump
  • Open or shorted wiring in the control circuit
  • Bad connectors or corroded terminals
  • Failed control module
  • Blown fuse
  • Faulty relay
  • Vacuum leaks in the system
  • Software issues in the engine control unit (ECU)

Common misdiagnoses

  • Faulty reductant injection air pump
  • Open or shorted wiring in the circuit
  • Failed engine control module (ECM)
  • Defective connectors or terminals
  • Issues with the reductant system (e.g., low fluid level)
  • Faulty sensors related to the reductant system
  • Problems with the exhaust aftertreatment system

Troubleshooting steps

  1. 1. Check for Additional Codes

    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 present

  2. 2. Inspect Wiring and Connectors

  3. 3. Visually inspect the wiring and connectors associated with the reductant injection air pump. Look for signs of damage, corrosion, or loose connections

  4. 4. Pay special attention to the wiring harness for any fraying or breaks

  5. 5. Test the Reductant Injection Air Pump

  6. 6. If accessible, test the air pump itself to ensure it is functioning correctly. You can do this by applying direct power to the pump to see if it operates

  7. 7. If the pump does not work when powered directly, it may need to be replaced

  8. 8. Check the Control Circuit

  9. 9. Use a multimeter to test the voltage and ground at the pump connector. Ensure that the control circuit is receiving the proper voltage from the engine control module (ECM)

  10. 10. Check for continuity in the wiring between the ECM and the pump

  11. 11. Inspect the ECM

  12. 12. If the wiring and pump are functioning correctly, the issue may lie with the ECM. Check for any software updates or reprogramming that may be needed

  13. 13. In some cases, the ECM may need to be replaced if it is determined to be faulty

  14. 14. Check for Blockages

  15. 15. Inspect the air intake and exhaust paths of the reductant injection system for any blockages that could affect performance

  16. 16. Clear Codes and Test Drive

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

  18. 18. Consult Technical Service Bulletins (TSBs)

  19. 19. Check for any manufacturer-specific TSBs related to the P2059 code, as there may be known issues or recalls that could apply to your vehicle

  20. 20. Seek Professional Help

  21. 21. 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 emissions systems and OBD-II diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P2059 code