P2279 code meaning
Intake Air System Leak (Bank 1)
Powertrain system Generic code P22xx codes Check engine light
What P2279 means
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.
P2279 at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P2279
- Malfunction indicator lamp on
- Whistling at idle, unstable or high idle speed
- Limp mode on some engines
Common causes of P2279
- Most likelyLeaking crankcase breather or PCV pressure-regulating valve
- PossibleLeak at intake manifold, hoses or seals after the air mass sensor
- Less likelyCamshaft timing offset
- Less likelyECM calibration needing an update
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Intake manifoldPcv valveCrankcase breatherCharge air pipeMass air flow sensor
What each part of P2279 means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 2 | Area: fuel and air metering (injector circuit). |
| 79 | The exact fault in that area. |
What to do next
- Note P2279 and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P2279
What does P2279 mean?
P2279 means "Intake Air System Leak (Bank 1)". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P2279?
Drive gently and only to a workshop. With P2279 the car can go into limp mode (reduced power) to protect itself.
Will P2279 fail an emissions test?
Yes, it can. P2279 is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P2279 to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P2279 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.