P0071 Outside air temperature sensor: reading or operation not right

By: Diagno editorial team · Updated: 2026-10-15

P0071 means: Outside air temperature sensor: reading or operation not right. A temperature sensor tells the computer the temperature of the air, coolant, fuel or oil. Drive gently and have the car checked soon. The repair usually costs about €30–200 in Estonia. The most common cause: faulty sensor.

What it means

A temperature sensor tells the computer the temperature of the air, coolant, fuel or oil. With a wrong reading the computer gets the mixture and the fan wrong. There is a signal, but the reading or operation isn't plausible. The cause may be the part itself or a real mechanical fault.

What you may notice

• Engine light on
• Hard cold starts
• The fan may run all the time
• Higher fuel consumption

What could be wrong

1. 1Faulty sensor
2. 2Corroded or loose connector
3. 3Broken or chafed wire
4. 4Engine computer fault (rare)

Repair difficulty: Easy

What you can check yourself

Check the sensor connector and make sure it is clipped in. On a cold engine, compare the reading with the outside temperature. You can do the simpler checks yourself.

How we fix it

1. We read the sensor on the diagnostic tool and compare it with other sensors
2. We check the connector, supply and ground
3. We repair the wiring or replace the sensor

Standard SAE description: Ambient Air Temperature Sensor Range/Performance