P0071 — Ambient Air Temperature Sensor Range/Performance
Low severityWhat it means
P0071 is stored when the engine control unit sees a fault involving the ambient air temperature sensor circuit. The ambient air temperature sensor reports outside air temperature, which the control unit and climate system use for the display, fan strategy and some fuelling decisions. A “range/performance” fault means the value is present but implausible — it does not agree with other sensors or expected conditions.
Common symptoms
- Readings that drift or disagree with related sensors
- Wrong outside-temperature reading on the dash
- Climate control behaving oddly
- Usually only a check engine light
Likely causes
- Drifting, contaminated or aged sensor
- A mechanical issue skewing the reading
- A faulty ambient air temperature sensor
- A wiring or connector fault, often from front-end damage
What to check first
- Cross-check the reading against related sensors in live data on a cold start
- Compare the sensor reading with actual outside temperature in live data
- Inspect the sensor (usually behind the front bumper) and its wiring
Can you keep driving?
Safe to drive; it mainly affects the temperature display and climate control, so fix it at your convenience.
Frequently asked questions
What is the most common cause of P0071?
The most likely cause is: Drifting, contaminated or aged sensor. Several other faults can set P0071 as well, so confirm the real cause with live data and the checks above before replacing any parts.
Can I just clear P0071 and keep driving?
Clearing P0071 with an OBD2 scanner turns the warning light off, but if the underlying fault has not been repaired the code will usually come back within a few drive cycles. Fix the cause first, then clear the code to confirm the repair worked.
How serious is P0071?
P0071 is a low-severity code. It rarely affects how the car drives, but it is still worth fixing so the engine runs efficiently and passes an emissions test.
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