P0071

Ambient Air Temperature Sensor Circuit A Range/Performance

Ambient air temperature Generic OBD-II Low

What it means

P0071 means the ambient (outside) air temperature sensor is reporting a value the ECM judges to be implausible or slow to change. This sensor mainly drives the outside-temperature display and some climate-control and minor fuel calculations, so its real-world impact is small — the engine runs normally and the car will still start. The usual cause is a failing sensor, poor wiring, or a sensor location picking up stray heat.

Low

Can I keep driving? Yes — this sensor mainly feeds the temperature display and minor calculations; the car drives normally, though the outside-temp reading may be wrong.

Real-world scan data

Seen in

796

scans in the past year

Found in

0.1%

of scans

0.2%

of scans that found faults

Appears alongside · share of P0071 scans

P0111in 69.8% of scans

P0704in 69.5% of scans

P0421in 69.2% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on
Inaccurate outside-temperature reading on the dash
Climate control or defrost behaving oddly
Minor effect on fuel trim on some vehicles

Common causes

Most likely first

Failed or drifting ambient air temperature sensor (most common)Likely
Sensor exposed to engine or road heat giving false readingsCommon
Damaged wiring or corroded connector at the sensorCommon
Failed ECM or HVAC module (rare)Less often

How to diagnose & fix

Work through it in order

Compare the sensor's reported temperature to actual outside temperature with a scan tool.
Inspect the sensor connector and wiring for damage or corrosion.
Check the sensor's resistance against a temperature-resistance chart.
Replace the ambient air temperature sensor if out of spec.
Clear the code and confirm the reading is realistic.

FAQ

Quick answers

Is it safe to drive with P0071?+

Yes. This sensor doesn't affect how the engine runs — at most you'll see a wrong outside-temperature display and quirky climate control.

Can I just clear P0071?+

It will return if the sensor reading stays implausible. Confirm the sensor and wiring are good, then clear.

Read & clear P0071 yourself

Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.

▶ Get it on Google Play

✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX