Understanding the P0073 OBD-II Trouble Code: A Comprehensive Guide for Vehicle Owners

Understanding the P0073 OBD-II Trouble Code: A Comprehensive Guide for Vehicle Owners

If you’ve ever seen your check engine light illuminate and had your vehicle scanned, you may have encountered the P0073 diagnostic trouble code. This code is related to the ambient air temperature sensor and can affect a wide range of vehicles. In this blog post, we’ll dive deep into what the P0073 code means, which vehicles are commonly affected, and how to diagnose and fix the issue.

What is the P0073 Code?

The P0073 code stands for “Ambient Air Temperature Sensor Circuit High Input.” This code indicates that the vehicle’s powertrain control module (PCM) has detected an unusually high voltage reading from the ambient air temperature sensor circuit. The ambient air temperature sensor measures the temperature of the outside air and is typically located in the front grille area of the vehicle.

Top 20 Vehicles Commonly Affected by P0073

While the P0073 code can appear in many different makes and models, here are 20 vehicles that frequently experience this issue:

  1. Ford F-150
  2. Chevrolet Silverado
  3. Dodge Ram
  4. Honda Civic
  5. Toyota Camry
  6. Nissan Altima
  7. Honda Accord
  8. Ford Explorer
  9. Jeep Grand Cherokee
  10. Chevrolet Malibu
  11. Toyota Corolla
  12. Ford Focus
  13. Hyundai Sonata
  14. Volkswagen Jetta
  15. BMW 3 Series
  16. Mercedes-Benz C-Class
  17. Audi A4
  18. Subaru Outback
  19. Mazda3
  20. Kia Optima

Implications for Vehicle Performance and Emissions

The P0073 code can have several impacts on your vehicle’s performance and comfort:

  • Climate Control Issues: The ambient air temperature sensor is crucial for the proper functioning of automatic climate control systems. A faulty sensor may lead to inaccurate temperature readings and improper climate control operation.
  • Fuel Efficiency: While not directly related to engine performance, inaccurate temperature readings could potentially affect the engine’s fuel mixture, leading to slightly reduced fuel efficiency.
  • Emissions: In most cases, this code doesn’t directly impact emissions. However, if it affects the engine’s fuel mixture, it could potentially lead to slightly increased emissions.
  • Comfort: An incorrect outside temperature display can be annoying for drivers who rely on this information.

Diagnosing and Fixing the P0073 Code

To diagnose and fix the P0073 code, follow these steps:

  1. Use an OBD-II Scanner: Confirm the P0073 code and check for any additional related codes.
  2. Visual Inspection: Check the ambient air temperature sensor and its wiring for visible damage or loose connections.
  3. Test the Sensor: Use a multimeter to test the sensor’s resistance. The resistance should change as the temperature changes.
  4. Check the Wiring: Inspect the wiring between the sensor and the PCM for any breaks or shorts.
  5. Verify Sensor Location: Ensure the sensor is properly shielded from direct sunlight and strong winds, as these can affect its readings.

Key Symptoms of P0073

  • Illuminated check engine light
  • Incorrect outside temperature display
  • Improper operation of automatic climate control system
  • In some cases, slight changes in fuel efficiency

Solutions for P0073

  • Replace the faulty ambient air temperature sensor
  • Repair or replace damaged wiring in the sensor circuit
  • Ensure proper placement and shielding of the sensor
  • In rare cases, update or replace the PCM if it’s determined to be faulty

Frequently Asked Questions

Q: Is it safe to drive with the P0073 code? A: Generally, it’s safe to drive with this code. However, you may experience discomfort due to improper climate control operation.

Q: How much does it cost to fix a P0073 code? A: Costs can vary, but replacing an ambient air temperature sensor typically ranges from $50 to $200, including parts and labor.

Q: How can I prevent the P0073 code from occurring? A: Regular maintenance is key. Keep electrical connections clean and secure, and address any engine performance issues promptly. Also, ensure the sensor is properly shielded and positioned.


While the P0073 code may not be as critical as some other OBD-II codes, it’s still important to address it promptly. Doing so will ensure your vehicle’s climate control system functions correctly, maintain accurate temperature readings, and potentially prevent any minor impacts on fuel efficiency. Remember, if you’re unsure about tackling the repairs yourself, it’s always best to consult with a qualified mechanic to ensure the problem is resolved correctly and safely.

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