P0072
Ambient Air Temperature Sensor Circuit A Low
Ambient air temperature sensor
Generic OBD-II
Low
What it means
P0072 means the ambient (outside) air temperature sensor circuit is reading a lower voltage than expected, usually pointing to a short to ground or a failed sensor. This sensor feeds the outside-temperature display and climate-control logic rather than core engine management, so the engine runs normally and the practical impact is minor — but the check-engine light stays on until it's fixed.
Low
Can I keep driving? Safe to drive — the engine runs normally; this sensor mainly feeds the outside-temperature display and climate control, so the impact is minor.
Common symptoms
What you'll notice
- Check-engine light on
- Outside-temperature display reads incorrectly (often stuck very low)
- Climate control or auto-defog behaving oddly
- Usually no change in how the engine drives
Common causes
Most likely first
- Short to ground in the ambient air temperature sensor wiringLikely
- Failed ambient air temperature sensor reading out of range lowCommon
- Corroded or damaged connector at the sensorCommon
- Faulty engine control module (ECM), rarelyLess often
How to diagnose & fix
Work through it in order
- Locate the ambient air temperature sensor (usually behind the front grille or bumper).
- Inspect its connector and wiring for a short to ground, corrosion, or damage.
- Compare the sensor's live reading to the actual outside temperature; a stuck-low value confirms the fault.
- Repair the wiring or replace the sensor if it reads out of range.
- Clear the code and confirm the temperature reading is realistic.
FAQ
Quick answers
Is it safe to drive with P0072?+
Yes. The ambient air temperature sensor feeds the temperature display and climate system, not core engine control, so the car drives normally. It's low priority but still worth fixing to clear the light.
Can I just clear P0072?+
It will return if the wiring short or failed sensor is still present, since the ECM keeps monitoring the circuit.
Related codes
Often seen with P0072
Read & clear P0072 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX