WOMS
P code powertrain Medium severity

P0585 Cruise Control System Circuit Malfunction

The OBD2 code P0585 indicates a malfunction in the cruise control system circuit, which may involve issues with the wiring, switches, or the cruise control module itself

Definition

The OBD2 code P0585 indicates a malfunction in the cruise control system circuit, which may involve issues with the wiring, switches, or the cruise control module itself

Common causes

  • Faulty cruise control switch
  • Damaged wiring or connectors
  • Malfunctioning brake pedal switch
  • Defective throttle position sensor
  • Failed cruise control module
  • Blown fuse related to the cruise control system
  • Issues with the vehicle's powertrain control module (PCM)

Common misdiagnoses

  • Throttle position sensor issues
  • Brake light switch failure
  • Accelerator pedal position sensor problems
  • Wiring or connector issues
  • Cruise control module failure
  • Faulty engine control module (ECM)
  • Malfunctioning speed sensor
  • Vacuum leaks in the cruise control system
  • Faulty cruise control actuator
  • Electrical shorts or open circuits in the cruise control system

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 and help identify related issues

  2. 2. Inspect the Cruise Control Switch

  3. 3. Check the cruise control switch for any visible damage or wear

  4. 4. Ensure that the switch is functioning properly. You can test it with a multimeter to see if it is sending the correct signals when pressed

  5. 5. Examine Wiring and Connectors

  6. 6. Inspect the wiring harness and connectors associated with the cruise control system for any signs of damage, corrosion, or loose connections

  7. 7. Pay special attention to the wiring that runs to the cruise control switch and the cruise control module

  8. 8. Test the Cruise Control Module

  9. 9. If the switch and wiring appear to be in good condition, the cruise control module itself may be faulty

  10. 10. Consult the vehicle’s service manual for testing procedures specific to the cruise control module

  11. 11. Check the Brake Switch

  12. 12. The cruise control system is often disabled when the brake pedal is pressed. A malfunctioning brake switch can cause the cruise control to fail

  13. 13. Test the brake switch to ensure it is functioning correctly and that it is not stuck in the "on" position

  14. 14. Inspect the Throttle Position Sensor (TPS)

  15. 15. The TPS provides input to the engine control module (ECM) regarding the position of the throttle. If it is malfunctioning, it can affect the cruise control system

  16. 16. Test the TPS for proper operation and calibration

  17. 17. Look for Vacuum Leaks

  18. 18. If your vehicle uses a vacuum-operated cruise control system, check for any vacuum leaks in the hoses and connections

  19. 19. Check Fuses and Relays

  20. 20. Inspect the fuses and relays associated with the cruise control system. Replace any blown fuses and test the relays for proper operation

  21. 21. Perform a System Reset

  22. 22. After addressing any issues found, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears

  23. 23. Consult a Professional

  24. 24. If you are unable to identify or resolve the issue after performing these steps, it may be best to consult a professional mechanic or technician who has experience with cruise control systems. By following these troubleshooting steps, you should be able to identify the cause of the P0585 code and take appropriate action to resolve the issue