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P code powertrain High severity

P0733 Gear 3 Incorrect ratio

The OBD2 code P0733 indicates that the transmission control module has detected an incorrect gear ratio in third gear, suggesting a potential issue with the transmission's performance or components

Definition

The OBD2 code P0733 indicates that the transmission control module has detected an incorrect gear ratio in third gear, suggesting a potential issue with the transmission's performance or components

Common causes

  • Low transmission fluid level
  • Faulty transmission fluid pump
  • Worn or damaged transmission components
  • Malfunctioning torque converter
  • Defective transmission control module (TCM)
  • Faulty speed sensors
  • Electrical issues or wiring problems
  • Incorrectly installed or damaged transmission filter
  • Software issues in the transmission control system

Common misdiagnoses

  • Transmission fluid issues
  • Faulty transmission control module (TCM)
  • Worn or damaged transmission components
  • Incorrectly calibrated speed sensors
  • Faulty engine control module (ECM)
  • Wiring or connector problems
  • Torque converter issues
  • Clutch problems in automatic transmissions
  • Incorrect gear ratio due to aftermarket modifications
  • Low battery voltage or electrical issues

Troubleshooting steps

  1. 1. Check Transmission Fluid Level and Condition

  2. 2. Ensure that the transmission fluid is at the correct level. Low fluid can cause shifting issues

  3. 3. Inspect the fluid for contamination, burning smell, or dark color. If the fluid is dirty or burnt, consider a transmission fluid change

  4. 4. Inspect for Leaks

  5. 5. Look for any signs of transmission fluid leaks around the transmission pan, seals, and hoses

  6. 6. Scan for Additional Codes

  7. 7. Use an OBD-II scanner to check for any other related trouble codes. This can provide more context for the issue

  8. 8. Check Transmission Range Sensor

  9. 9. The transmission range sensor (or neutral safety switch) can affect shifting. Ensure it is functioning correctly and is properly aligned

  10. 10. Inspect Wiring and Connectors

  11. 11. Check the wiring and connectors related to the transmission control module and sensors for any signs of damage, corrosion, or loose connections

  12. 12. Test the Input and Output Speed Sensors

  13. 13. The input and output speed sensors monitor the transmission's performance. If either sensor is faulty, it can lead to incorrect gear ratio readings. Test their resistance and output signals

  14. 14. Examine the Transmission Control Module (TCM)

  15. 15. Ensure that the TCM is functioning properly. If there are issues with the TCM, it may need to be reprogrammed or replaced

  16. 16. Check for Mechanical Issues

  17. 17. Inspect the transmission for internal mechanical problems, such as worn clutches, bands, or gears. This may require a professional transmission technician

  18. 18. Perform a Transmission Fluid Flush

  19. 19. If the fluid is contaminated, a complete flush may help improve performance. However, this should be done with caution, as it can sometimes exacerbate existing issues

  20. 20. Road Test the Vehicle

  21. 21. After performing the above checks, take the vehicle for a test drive to see if the code returns and to observe the transmission's behavior. 1

  22. 22. Consult a Professional

  23. 23. If the issue persists after performing these steps, it may be best to consult a professional mechanic or transmission specialist for further diagnosis and repair. By following these troubleshooting steps, you can identify the underlying cause of the P0733 code and take appropriate action to resolve the issue