MAF Limp mode (P0101, 2011-1, 2011-2, 2633-1, 2624-1)
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Joined: Jul 2024
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W211 bluetec 2008
MAF Limp mode (P0101, 2011-1, 2011-2, 2633-1, 2624-1)
My 2008 w211 bluetec has this weird problem where it goes into limp mode, the only codes are the ones listed above in the title. It does it usually after a hard acceleration. I used a scanner to check live data and the MAF and IAT do both work but the intake air temp and boost pressure are just barely out of the parameters (1-5 degrees and units of boost). All though i did find a way to bypass limp mode completely. If i start the engine and then unplug both MAF’s while the car is running i can drive it as hard as i want without putting it into limp mode and it drives very good. If i start with MAF unplugged it goes into limp mode immediately and will go into limp mode with MAF connected after a hard acceleration. Ive checked all the hoses, wires, turbo, intake for any restrictions and cannot find anything out of the ordinary. I was planning on installing a switch on the ground wire of the MAF downstream of where they join so i can bypass limp mode without having to pop my hood every time i turn my engine on. Any advice or pointers would be appreciated.
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Joined: Aug 2025
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2008 E320 Bluetec
Update. I tried this modification with a twist. I cleared all the codes, started the car and disconnected the right, passenger side MAT/IAT sensor while running, The car runs perfectly although it does now show a ton of codes associated with that temporary hack. I do not need to repeat anything, just start and run. Runs perfectly and fuel economy is good. Bottom line no limp mode. Next step is to run or replace wires from connector to ECM or at least test them. My guess is that it is chafed wire in the loom (very intermittent) or the ECM itself. Just for reference the only two codes present were 2011-1 and 2011-2 and would cause limp mode after a short drive. I am told these codes mean an open or shorted wiring circuit and apply to either sensor (left or right).
Last edited by enright77; Aug 21, 2025 at 07:21 PM.
