P0071: Ambient Air Temperature Sensor Circuit A Range/Performance
What to do
No driveability impact. If the displayed temperature is high after parking and falls once you drive, that pattern is worth reporting — it points at mounting or airflow rather than the sensor.
What this code means
The ambient temperature reading is electrically plausible but wrong — it does not agree with the other temperature sensors the module can see, or it fails to change when it should. A classic cause is heat soak: a sensor mounted where engine bay heat reaches it will read far too high after a stop, then slowly recover once moving. Check where the sensor is mounted before assuming it has failed.
Likely causes
Start here
Less common
- Debris blocking sensor airflow · easy
- Corroded or loose connector · easy
Symptoms
Components involved
Information, not instruction
CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.
Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.
Community experience
Be the first to write this up
Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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