WOMS
C code chassis Medium severity

C0693 Damper Control Relay Circuit High

The OBD2 code C0693 indicates a problem with the damper control relay circuit, specifically that the circuit is reading a high voltage or resistance when it should not be

Definition

The OBD2 code C0693 indicates a problem with the damper control relay circuit, specifically that the circuit is reading a high voltage or resistance when it should not be

Common causes

  • Faulty damper control relay
  • Short circuit in the damper control circuit
  • Open circuit in the damper control circuit
  • Damaged wiring or connectors
  • Faulty HVAC control module
  • Malfunctioning climate control system
  • Poor ground connection

Common misdiagnoses

  • Faulty HVAC control module
  • Damaged wiring or connectors
  • Faulty damper actuator
  • Incorrectly diagnosed climate control issues
  • Battery or charging system problems
  • Faulty engine control module (ECM)
  • Issues with other relay circuits
  • Software or calibration errors in the HVAC 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 Damper Control Relay

    Locate the damper control relay in the vehicle's fuse box or relay panel

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

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

  5. 5. Examine Wiring and Connectors

    Inspect the wiring and connectors associated with the damper control relay for any signs of damage, fraying, or corrosion

  6. 6. Ensure that all connections are secure and free from moisture

  7. 7. Test the Relay Circuit

    Use a multimeter to test the voltage and ground at the relay terminals

  8. 8. Check for proper voltage when the ignition is on and when the HVAC system is activated

  9. 9. If the voltage is higher than expected, there may be a short circuit or a problem with the control module

  10. 10. Check the HVAC Control Module

    The HVAC control module may be sending incorrect signals to the damper control relay

  11. 11. Inspect the module for any signs of damage or malfunction

  12. 12. If necessary, perform a reset or reprogram the module according to the manufacturer's specifications

  13. 13. Inspect the Damper Actuator

    The damper actuator controls the airflow direction and may be malfunctioning

  14. 14. Check for proper operation of the actuator and ensure it is not stuck or damaged

  15. 15. Look for Ground Issues

    Ensure that the ground connections for the damper control relay and HVAC system are secure and free from corrosion

  16. 16. A poor ground can lead to high voltage readings

  17. 17. Perform a Visual Inspection

    Conduct a thorough visual inspection of the entire HVAC system for any signs of leaks, blockages, or other issues that could affect operation

  18. 18. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the C0693 code for your specific vehicle make and model. Manufacturers may have issued guidance on common issues and fixes

  19. 19. Clear the Codes and Test Drive

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

  20. 20. Take the vehicle for a test drive to see if the code reappears.1

  21. 21. Seek Professional Help

    If the issue persists after following these steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle's HVAC system. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C0693 code