Skip the auto shop - Our mechanics make house calls
  1. Home
  2. Articles
  3. P0071 OBD-II Trouble Code: Ambient Air Temperature Sensor Range/Performance

P0071 OBD-II Trouble Code: Ambient Air Temperature Sensor Range/Performance

Check Engine Light

P0071 code definition

Ambient Air Temperature Sensor Range/Performance Issue

Depending on the type of vehicle these are some related OBD-II Diagnostic Trouble Codes:

  • P0070: Ambient Air Temperature Sensor Circuit
  • P0072: Ambient Air Temperature Sensor Circuit Low Input
  • P0073: Ambient Air Temperature Sensor Circuit High Input

What the P0071 code means

The ambient air temperature sensor provides the Power Control Module (PCM) with information that is necessary to monitor the ambient air temperature and intake air temperature. When the ambient air temperature to intake air temperature ratio is abnormal, this triggers the P0071 trouble code, causing the Check Engine Light to come on.

What causes the P0071 code?

The following are known causes for the P0071 trouble code:

  • Failed or faulty ambient air temperature sensor
  • A short in wires or broken wires
  • An open or shorted ambient air temperature harness
  • Corroded electrical circuitry and/or connectors
  • Sensor covered by foreign objects

What are the symptoms of the P0071 code?

A Check Engine Light is the most common symptom of the P0071 trouble code. It is also possible that the climate control system (heat and/or air condition controls) will stop working as it should, indicating that there is a fault in the ambient air temperature sensor.

How does a mechanic diagnose the P0071 code?

  • Recording the freeze frame data and diagnostic trouble codes present is the first step in diagnosing the P0071 trouble code. This can be done by using an OBD-II scanner.

  • After receiving the P0071 trouble code from the OBD-II scanner, the wiring and connectors going to the ambient air temperature sensor should be inspected for shorts, breaks, and corrosion in the circuitry and/or connector. It is also a good idea to make sure that there isn’t anything covering the sensor, which could cause the P0071 code to be triggered.

  • After inspecting these components and repairing and/or replacing as needed, the trouble code should be cleared and the vehicle test driven. This part of the diagnostic process will ensure that the ambient air temperature sensor issue has been resolved and that there are no other problems attributing to the P0071 trouble code.

  • The ambient air temperature sensor will need to be replaced if the P0071 diagnostic trouble code quickly returns during the test drive. If the P0071 diagnostic trouble code returns, but the return is not immediate, an intermittent problem has been indicated and further diagnosis of the voltage going to the PCM would be required.

  • In very rare instances, when all of the above diagnostic measures do not resolve the ambient air temperature sensor issue, this could indicate that there is a problem with the Power Control Module (PCM). This is unusual, but is still a possibility.

Common mistakes when diagnosing the P0071 code

It is important to check the ambient air temperature sensor wiring and connector before replacing the sensor itself. Too often, the ambient air temperature sensor is replaced when a defect in the wiring and/or connector could have resolved the P0071 trouble code.

How serious is the P0071 code?

The ambient air temperature sensor could affect the climate control system (heat and/or air condition controls), which could cause uncomfortable driving conditions. The P0071 trouble code would not be classified as a serious one because it does not interfere with the vehicle's drivability function or prevent the car from running properly.

What repairs can fix the P0071 code?

  • Repairing or replacing wires with shorts and/or breaks
  • Cleaning corrosion in the electric circuitry and/or connector
  • Replacing the faulty ambient air temperature sensor

Additional comments for consideration regarding the P0071 code

Although the most common solution to resolving the P0071 diagnostic trouble code will be to replace the ambient air temperature sensor, the wiring, connector, and harness need to first be excluded as the problem.

Need help with a P0071 code?

YourMechanic offers certified mechanics who will come to your home or office to diagnose and repair your vehicle. Get a quote and book an appointment online or speak to a service advisor at 1-800-701-6230.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.


More related articles

How to Get a Louisiana Driver's Permit
s licensing program. The first step in this program is to obtain...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP)...

Related questions

Q: Check engine light - one shop told me it was a knock sensor, and another place told me oxygen sensor 1995 Toyota 4Runner

Hello - it is possible there are differences between the 2 scanners (i.e. software levels, etc.). It is also possible that one code or the other was a transient, or temporary, code, and was not present when the 2nd test...

Q: Q: What is causing the engine misfires?

It is usually best to change all the coils when chasing a misfire with engines of this age and mileage. If one is weak, they are likely all weak. When you changed the plugs, was there oil in the spark...

Q: Failed emission test, code P0071

Hi. There could be a problem with the sensor that was replace being faulty or defective causing you not to pass emission. There are also are drive cycles that the Pcm has to go through to properly clear the memory...