P code powertrain Medium severity

P0720 Output Speed Sensor Circuit Malfunction

The OBD2 code P0720 indicates a malfunction in the output speed sensor circuit, which measures the rotational speed of the transmission output shaft

Definition

The OBD2 code P0720 indicates a malfunction in the output speed sensor circuit, which measures the rotational speed of the transmission output shaft

Common causes

  • Faulty output speed sensor
  • Damaged wiring or connectors
  • Poor electrical connections
  • Malfunctioning transmission control module (TCM)
  • Issues with the vehicle's computer system
  • Low transmission fluid levels
  • Internal transmission problems
  • Corroded or shorted circuits

Common misdiagnoses

  • Transmission issues
  • Vehicle speed sensor failure
  • Engine control module (ECM) problems
  • Wiring or connector issues
  • Input speed sensor malfunction
  • Torque converter problems
  • Faulty transmission fluid level or condition
  • ABS sensor issues

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Codes related to the transmission or other sensors can provide additional context

  2. 2. Inspect the Output Speed Sensor

    Locate the output speed sensor (usually found on the transmission)

  3. 3. Check for physical damage, corrosion, or loose connections at the sensor and its wiring harness

  4. 4. Test the Sensor

    Use a multimeter to test the output speed sensor. Check for proper resistance and voltage output according to the manufacturer's specifications

  5. 5. If the sensor is faulty, replace it

  6. 6. Check Wiring and Connectors

    Inspect the wiring and connectors leading to the output speed sensor for any signs of wear, fraying, or damage

  7. 7. Ensure that all connections are secure and free of corrosion

  8. 8. Inspect the Transmission Fluid

    Check the transmission fluid level and condition. Low or dirty fluid can affect sensor performance

  9. 9. If the fluid is low, top it off or change it if it appears dirty or burnt

  10. 10. Test the Circuit

    Use a multimeter to check for continuity in the wiring between the output speed sensor and the ECM/TCM

  11. 11. Look for any shorts to ground or open circuits

  12. 12. Check for Mechanical Issues

    Inspect the transmission for any mechanical issues that could affect the output speed sensor's operation, such as a failing torque converter or internal transmission problems

  13. 13. Clear Codes and Test Drive

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

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

  15. 15. Seek Professional Help

    If the issue persists after performing these steps, consider seeking help from a professional mechanic or technician who has experience with transmission diagnostics. By following these troubleshooting steps, you can systematically identify and resolve the issue related to the P0720 code