Ambient Air Temperature Sensor Range/Performance
The P0071 code means the vehicle's onboard diagnostic system has detected: Ambient Air Temperature Sensor Range/Performance. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- easy
- Estimated cost
- $30 - $180 (parts and labor)
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What Are the Symptoms of P0071?
- Check Engine Light on
- Incorrect ambient temperature reading on dashboard
- Minor fuel trim adjustments
- Automatic climate control may behave erratically
What Causes P0071? (Most Likely First)
- Ambient air temperature sensor reading out of range Very High
- Sensor contaminated with road debris or oil High
- Poor sensor ground connection Moderate
- PCM software calibration issue Low
Can I Still Drive with P0071?
Yes, but fix soon. P0071 is rated low severity. It is not an immediate stop-driving fault, but it will not clear itself — book the repair rather than ignoring the light.
Frequently Asked Questions
Is P0071 a serious code?
No, P0071 is a low-severity code. It indicates the ambient air temperature sensor is reading outside the expected range but does not significantly affect driveability.
What causes the ambient air temp sensor to read incorrectly?
The most common cause is a contaminated or failing sensor. Road salt, debris, and age can degrade the sensor element over time.
Will this code affect my emissions test?
Yes, any illuminated Check Engine Light will cause an emissions inspection failure, even for a low-severity code like P0071.
Mechanics Guide Step-by-step diagnosis
How Do You Diagnose P0071?
-
Read ambient air temp PID with scan tool and compare to a known accurate thermometer reading.
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Inspect sensor for physical contamination, road debris, or oil film that could insulate the sensing element.
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Check sensor ground circuit for resistance. Should be less than 0.5 ohms to ground.
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If sensor reads correctly at room temp, monitor the value during a drive to check for intermittent range faults.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Which Vehicles Commonly Get P0071?
- 2010-2020 Chevrolet Equinox
- 2012-2019 Ford Escape
- 2008-2018 Honda CR-V
- 2011-2020 Toyota RAV4
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