This TSB applies to all 2008-2013 VW vehicles. Rough running, engine noise or MIL on with DTCs P0300, P0301, P0302, P0303, P0304, P2279, P1297, P1093 or P2187 stored in the ECM. A faulty PCV valve will allow pressurized intake air back into the valve cover/crankcase. This pressurized air can blow out of several openings. The oil filler cap, air filter and dipstick should first be checked for evidence of oil blowout.

P0300: Ransom/multiple cylinder misfire detected

P0301: Cylinder 1 misfire detected

P0302: Cylinder 2 misfire detected

P0303: Cylinder 3 misfire detected

P0304: Cylinder 4 misfire detected

P2279: Intake air system leak

P1297: Charger throttle connection, drop in pressure

P1093: Bank 1 fuel measuring system 2 malfunction

P2187: System too lean at idle, bank 1

-          With the engine off, remove the engine cover and locate the hose connecting the intake manifold to the crankcase. Disconnect the hose from the intake manifold side and clean off any residue with a cloth. Blow into the hose. If there is some air resistance, the check valve is operating properly. If there is no resistance, the PCV valve must be replaced.

-          With the engine running, disconnect the hose from the valve cover. Plug the hose and check idle quality. If the idle quality improves, replace the PCV valve.

-          With the engine running, remove the dipstick. If idle quality improves, replace the PCV valve.

-          Remove the cap from the oil filler hole on the valve cover. Place a stiff piece of paper over the opening. The paper should be sucked against the hole within a couple of seconds if the PCV valve is operating properly.


The best measurable way to ensure the functionality of the system is fuel trim read8ings in MVB32. If faults pertaining to this part are found, do not erase the faults. Proceed with the steps outlined in this bulletin prior to following the GFF test plan to avoid erasing fuel trim readings.

  1. Using the VAS tester, read current fuel trim level in MVB32 field (idle fuel trim) and 2 (part throttle). Normal values are 0 +/- 3 in both fields.
  2. Replace the original PCV valve with a known good valve.
  3. Make sure that no additional loads are turned on during the test, such as A/C, heated seats, etc.
  4. If the noise goes away or if the engine is no longer running rough, replace the PCV valve.
  5. Using the VAS tester, run basic settings 32 for at least 5 minutes.
  6. While running basic settings 32 for 5 minutes, we can monitor fields 1 and 2 for fuel trim readings.
  7. If fuel trim values improve and move closer to 0, replace the PCV valve.
  8. If values do not improve, re-install the original PCV valve. Use of the GFF is permitted at this point.
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