P0072 means Ambient Air Temperature Sensor Circuit Low. The outside air temperature sensor circuit voltage is lower than expected, which usually looks like a very hot reading. It is a generic OBD-II code, so the definition is the same on any make, but the most likely cause varies by engine; confirm with a scan tool and the service information for your vehicle before buying parts.
What P0072 means
Most engine sensors receive a 5-volt reference and return a signal between roughly 0 and 5 volts. Codes ending in circuit high or circuit low usually point to an electrical fault: an open circuit, a short or an unplugged connector. Range/performance codes mean a signal is present but disagrees with what the computer expects from the other sensors, which more often points to a dirty sensor, an air leak or a mechanical problem.
P0072 symptoms
- Wrong outside temperature on the dash
- Automatic climate control behaving oddly
- Check engine light on some vehicles
Common causes of P0072
- Damaged sensor, often behind the front bumper or grille
- Wiring damaged by road debris or a minor collision
- Corroded connector
How to diagnose P0072
- Compare the reading with actual outside temperature
- Inspect the sensor and wiring behind the bumper
- Check sensor resistance against specification
Can you drive with P0072?
Yes; it mainly affects climate control and the temperature display.
P0072 tips
Check the sensor behind the front bumper or grille for damage after a minor collision or debris strike.
Will P0072 clear itself?
If the fault stops, the computer turns off the check engine light by itself after several drive cycles without seeing it again, and the code stays in memory as history for a while. Clearing P0072 with a scan tool after a repair is fine, but if the cause is still there the code returns, sometimes within one drive. Disconnecting the battery also clears codes on most vehicles, but it erases learned fuel trims and idle settings as well.
Related codes
| Code | Meaning |
|---|---|
| P0071 | Ambient Air Temperature Sensor Range/Performance |
| P0073 | Ambient Air Temperature Sensor Circuit High |
| P0110 | Intake Air Temperature Sensor Circuit |
Guides that help
When it is more than a sensor
Sensor codes are usually fixed with a sensor, a connector, wiring or a leak repair rather than major parts. If testing turns up internal engine trouble instead, see how to tell if an engine is blown and compare engines by code on our engines page.
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