WOMS
C code chassis Medium severity

C1738 Air Suspension RR Corner Down Timeout

The OBD2 code C1738 indicates a malfunction in the air suspension system, specifically that the right rear corner of the suspension has not reached the desired height within the expected time frame, suggesting a...

Definition

The OBD2 code C1738 indicates a malfunction in the air suspension system, specifically that the right rear corner of the suspension has not reached the desired height within the expected time frame, suggesting a potential issue with the air spring, compressor, or related components

Common causes

  • Faulty air suspension compressor
  • Leaking air spring or bag
  • Blocked or damaged air lines
  • Defective height sensor
  • Electrical connection issues (wiring or connectors)
  • Malfunctioning air suspension control module
  • Low air pressure in the system
  • Faulty relay or fuse related to the air suspension system

Common misdiagnoses

  • Faulty air suspension compressor
  • Leaking air bags or lines
  • Defective height sensors
  • Wiring issues or short circuits
  • Malfunctioning control module
  • Incorrectly calibrated suspension system
  • Tire pressure issues
  • Suspension control valve problems

Troubleshooting steps

  1. 1. Visual Inspection

  2. 2. Check for any visible damage to the air suspension components, including the air spring, air lines, and fittings

  3. 3. Inspect the right rear corner for any signs of leaks or wear

  4. 4. Check for Air Leaks

  5. 5. Use soapy water to check for air leaks in the air spring and associated lines. Bubbles will form at the site of any leaks

  6. 6. If leaks are found, repair or replace the affected components

  7. 7. Inspect the Air Compressor

  8. 8. Ensure that the air compressor is functioning properly. Listen for unusual noises or lack of operation

  9. 9. Check the compressor relay and fuse to ensure they are working correctly

  10. 10. Check the Height Sensors

  11. 11. Inspect the height sensor for the right rear corner. Ensure it is properly connected and not damaged

  12. 12. Test the height sensor for proper operation using a multimeter or scan tool

  13. 13. Scan for Additional Codes

  14. 14. Use an OBD-II scanner to check for any additional trouble codes that may provide more context to the issue

  15. 15. Address any other codes that may be present, as they could be related

  16. 16. Test the Air Suspension Control Module

  17. 17. If all other components appear to be functioning correctly, the issue may lie with the air suspension control module itself

  18. 18. Check for proper connections and any signs of corrosion or damage

  19. 19. Check the Vehicle's Battery and Charging System

  20. 20. Ensure that the vehicle's battery is fully charged and that the charging system is functioning properly. Low voltage can affect the operation of the air suspension system

  21. 21. Reset the System

  22. 22. After addressing any issues found, clear the trouble codes using a scan tool and perform a system reset. Monitor the system to see if the code returns

  23. 23. Professional Diagnosis

  24. 24. If the issue persists after performing the above steps, consider seeking assistance from a professional mechanic or a dealership with experience in air suspension systems. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the C1738 code. Always refer to the vehicle's service manual for specific procedures and specifications related to your make and model