P2279Intake Air System Leak (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2279 means the ECM has concluded that air enters the engine without being measured or expected, for example because the air mass sensor, manifold pressure and throttle position no longer agree with its air model. Volkswagen and Audi use it widely. On the 2013 to 2016 Audi A6, A7 and A8 4.0 TFSI, a leaking pressure-regulating valve in the crankcase breather module set P2279 with P0507 and a metallic whistle at warm idle; a fabric-reinforced membrane fixed it. On 2.0 TFSI engines (BPY, CCTA and others) a check valve that did not seal under boost let pressure into the crankcase, logging P2279, P2187 and P1297 with oil leaking at the filler cap. For the 2.5 litre five-cylinder Volkswagen advises checking cam timing first, since a timing offset changes the air the engine draws. Diesels set it too: the Mercedes OM651 2.2 in the international Jeep Compass and Patriot logged it with limp mode and got a new air filter and software.
- What you may notice
- Malfunction indicator lamp on
- Whistling at idle, unstable or high idle speed
- Limp mode on some engines
- Likely causes
- LikelyLeaking crankcase breather or PCV pressure-regulating valve
- PossibleLeak at intake manifold, hoses or seals after the air mass sensor
- RareCamshaft timing offset
- RareECM calibration needing an update
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.