OBD-II code · Powertrain (generic)

P009A Intake Air Temperature/Ambient Air Temperature Correlation

Intake air temperature and ambient air temperature readings deviate beyond plausible limits — at engine off both should match within tolerance.

Is it safe to drive with P009A?

Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.

Common causes

  • Most likelyOne sensor drifted

Repair at a glance

Difficulty
Easy
DIY friendly
Often, with basic tools
Typical labour
0.3–1.5 h
Emissions test
Likely to fail
After the fix
A drive cycle is needed before the light stays off
Parts involved
Iat Sensor, Ambient Air Temp Sensor

Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.