WOMS
P code powertrain Medium severity

P0071 Ambient Air Temperature Sensor Range/Performance

The OBD2 code P0071 indicates that the ambient air temperature sensor is reporting a range or performance issue, suggesting that the sensor's readings are outside the expected parameters

Definition

The OBD2 code P0071 indicates that the ambient air temperature sensor is reporting a range or performance issue, suggesting that the sensor's readings are outside the expected parameters

Common causes

  • Faulty ambient air temperature sensor
  • Wiring issues (shorts, opens, or corrosion)
  • Poor electrical connections
  • Faulty engine control module (ECM)
  • Incorrect sensor calibration
  • Environmental factors (extreme temperatures)
  • Sensor placement issues (obstruction or damage)

Common misdiagnoses

  • Faulty Engine Coolant Temperature Sensor
  • Faulty Intake Air Temperature Sensor
  • Faulty Thermostat
  • Wiring Issues or Short Circuits
  • Faulty Engine Control Module (ECM)
  • Air Conditioning System Issues
  • Faulty Cabin Temperature Sensor
  • Incorrectly Installed or Damaged Ambient Air Temperature Sensor

Troubleshooting steps

  1. 1. Check the Code

    Use an OBD-II scanner to confirm the P0071 code and check for any additional codes that may provide more context about the issue

  2. 2. Inspect the Ambient Air Temperature Sensor

  3. 3. Locate the ambient air temperature sensor, which is usually mounted in the front of the vehicle, near the grille or in the air intake area

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

  5. 5. Test the Sensor

  6. 6. Disconnect the sensor and use a multimeter to measure its resistance. Compare the readings to the specifications provided in the vehicle's service manual

  7. 7. If the resistance is out of range, the sensor may need to be replaced

  8. 8. Check Wiring and Connectors

  9. 9. Inspect the wiring harness for any signs of wear, fraying, or damage

  10. 10. Ensure that all connectors are clean, secure, and free of corrosion

  11. 11. Check for Short Circuits or Open Circuits

  12. 12. Use a multimeter to check for continuity in the wiring between the sensor and the engine control module (ECM)

  13. 13. Look for any short circuits to ground or open circuits that could affect the sensor's performance

  14. 14. Inspect the ECM

  15. 15. In rare cases, the issue may be related to the engine control module itself. Check for any software updates or known issues with the ECM that could affect sensor readings

  16. 16. Clear the Code and Test Drive

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

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

  19. 19. Monitor Live Data

  20. 20. Use the OBD-II scanner to monitor live data from the ambient air temperature sensor while driving. Ensure that the readings are consistent with the actual ambient temperature

  21. 21. Consult Technical Service Bulletins (TSBs)

  22. 22. Check for any TSBs related to the P0071 code for your specific vehicle make and model. Manufacturers may have issued guidance or fixes for known issues

  23. 23. Seek Professional Help

  24. 24. If the problem persists after following these steps, consider consulting a professional mechanic for further diagnosis and repair. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the P0071 code