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P226321 - Lag in Acceleration - 2012 CLS550 W218/M278
P226321 (P2263) - ECM - "The boost pressure deviates from the specified value. The signal amplitude is less than the minimal amplitude."
2012 CLS550 W218 M278 Engine
Hey everyone,
So I noticed recently an intermittent issue where while driving and pushing down on the gas peddle, where I would normally expect a downshift by 2 gears (especially in S mode) and aggressive acceleration, I am not getting the oomph anymore and/or I get a delayed lag/reaction where it seems to go limp before beginning to accelerate. Recently, after pulling a U-turn, coasting at about 15mph and then going full throttle, I noticed a long 1-1.5 second pause and hesitation where nothing was happening and then finally some acceleration kicked in and my CEL immediately came on. A scan with my Creader Elite shows a P226321 with no other real associated messages:
After scouring the internet I came across a few sources pointing to the vacuum solenoid check valve, I completed the following fix but it did NOT solve my problem. After resetting my CEL codes, I went on a test drive, first 10 minutes or so, seemed like everything was back to normal but once engine was heated up, the lagging and soft acceleration started to occur again and shortly after I got the CEL and the same message on my scanner shows up.
So now I am wondering where to look next. I am fearful that the issues may lie directly with one of my 2 turbochargers. Other reading I did online is also pointing to a possible hose somewhere in the system being compromised or cracked etc but not sure where to begin looking as I think there are hoses connected to the associated system from front to back of the engine.
Also worth mentioning, I have a Stage 1 ECU boost from OE Tuning running on 91 Octane selection.
I've now moved on to the boost pressure solenoid and am testing it for failure. I have found a replacement online but am wondering what this subtle difference is even though the part numbers seem to match:
My original one with a box apparatus over the side The replacement without...
The replacement solenoid I ordered was NOT as pictured in my latter photo, it did resemble the original design but unfortunately it was a chinese part and not OEM as they depicted (even though they charged OEM prices) so I sent it back and am awaiting another part from another dealer.
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