Quote:
Originally Posted by frankenm
Decided I'm going to start a thread on this to hopefully help myself and others with the dreaded limp mode/engine malfunction that randomly happens
I've been getting a Engine Malfunction/Reduced power message every once in a while for no apparent reason, seems to usually happen on the highway during soft acceleration ...
I've replaced the following so far in an attempt to remedy this problem,
Bank 2 Injectors
Bank 1 & 2 HPFP's
All Crankcase vent lines
Spark Plugs
Coils
Bank 2 Turbo Diverter valve
Bank 1 & 2 Air Intakes
Probably a few other things I can't remember right now ...
My truck does not throw any kind of check engine light when this happens, just goes into limp mode and turning the truck off and on again makes it go away.
It only happens on the highway, usually when I'm going to pass or getting on the on-ramp and slowly accelerating ... It could be that the truck doesn't like to be driving slowly like this so it goes into limp mode as a way to get back!!??! 
I think this is a software issue with the car itself, I haven't hooked up my computer to the car yet when it goes into limp mode but I'm not even sure if it will register since it doesn't throw a CEL.
I know others have similar issues with this and hopefully we can come together and figure out what it is and help each other out here.
Just an FYI I have not had BMW diagnosis this and giving the only dealer in my area is a major crook and I DIY it is not worth it for me to waste my money on it for them to tell me everything is fine. |
I got this problem RIGHT after I got my exhaust done, like pulling out of the shops parking lot. That's the only reason I started my diagnosis there. Looked under the vehicle and noticed that the two rubber hoses for the valves from the stock muffler were just hanging. After plugging them up the problem was gone.
Granted, mine was flashing the warning on somewhat harder acceleration runs (by no means WOT). I also noticed that it would reduce the power but would not go into limp mode, per se. Warning would be gone upon restart, like yours.
If you have an aftermarket muffler, that's where I'd check next.
Hopes this helps, good luck.