Engine - MIL ON/Rough Idle/ DTC's P0507/P2279/P2187
01 MIL on, engine stalls or idles erratically immediately after cold start in extremely cold weather (below 20锟斤拷F)
17 09 16
2021443/2
December 1, 2009
Affected Vehicles
126
Condition
Weather is extremely cold (below 20锟斤拷F or -6.7锟斤拷C), and one of the following conditions is present:
^ MIL on. Possible DTCs (P0507, P2279, or P2187).
^ Uneven idle or engine immediately stalls prior to shifting out of Park at first cold start. Engine operation normal after warm-up.
Technical Background
It is normal for condensed water to accumulate in the engine oil during extended periods of cold weather (below freezing) and excessive vehicle
short-trip operation. This water usually evaporates when the engine reaches operating temperature and exits through the crankcase ventilation
system.
However, if the vehicle is mainly used for short trips and the engine does not reach operating temperature, an excessive amount of condensed water
may collect in the crankcase pressure regulating valve and freeze over night (Figure 1). This could lead to a temporary malfunction of the crankcase
pressure regulating valve on cold engine start and result in a rough idle or engine stall until warm crankcase gases melt the ice.
A special winter pressure regulating valve is available for vehicles in cold weather regions operated under extended short trip conditions and
exhibiting the above symptoms.
Tip: This condition only occurs when ambient air temperatures fall below freezing and allow residual water buildup in the crankcase pressure
regulating valve to freeze.
Production Solution
Service
1. Remove the oil filler cap and check for moisture.
If the oil filler cap is heavily coated with grey or white foam, a large amount of water is present in the engine oil.
2. Remove the crankcase pressure regulating valve and check for presence of ice or excessive moisture buildup.
3. Check the part number of the crankcase pressure regulating valve. If the part number of the crankcase pressure regulating valve is 06F 129 101E,
replace with 06F 129 101M.
Note:
Install part number 06F 129 101M only if the removed part number is 06F 129 101E. Damage could occur.
4. Replace the engine oil and filter.
5. Erase any DTCs, if present.
127
6. Perform test drive and verify repair.
Warranty
Required Parts and Tools
Required Tool:
VAS 5051B/5052
Additional Information
All parts and service references provided in this TSB are subject to change and/or removal. Always check with your Parts Department and service
manuals for the latest information.
