Powertrain, generic (extended)

P2279 Intake Air System Leak (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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.

Likely causes

Leaking crankcase breather or PCV pressure-regulating valve
Leak at intake manifold, hoses or seals after the air mass sensor
Camshaft timing offset
ECM calibration needing an update

Symptoms

  • Malfunction indicator lamp on
  • Whistling at idle, unstable or high idle speed
  • Limp mode on some engines

Repair estimate

DifficultyMediumDIY possible
Parts and labour€20–600
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

intake manifoldpcv valvecrankcase breathercharge air pipemass air flow sensor

Related codes

P0507P2187P0171P2073P0101

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov.