OM651 P2779 fault 2012 C250 cdi

[Tonygw]

Hi Guys

My 2012 C250 CDI threw and engine light today, diagnosed as code P2779

Any clues or common failures I can start to look at? I think its some kind of air intake leak or something?

Cheers
Tony

 

[Marcbennett]

Hi, 651 engine has a problem with bolt snapping on intake manifold. That could possibly be your fault, can you hear any leaks when driving on boost?


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[Tonygw]

thanks for the reply, yes a slight hiss but difficult to tell. Car is down on power significantly

Is it a big job to fix? I havent had chance to investigate due to being at work all day.

But any common areas to check would be helpful!

 

[CowleyStJames]

Are you sure it's not P2279?
That indicates an air leak has occurred on the "metered" side of the intake manifold. There is more air entering the intake manifold than the mass airflow or MAP (manifold absolute pressure) sensor would suggest.
If it really is P2779, then that's a transmission downshift switch fault.
That allows you to manually change down the transmission gear using either the manual shift gate on the gear shift, or the paddle shifters located behind the steering wheel. If the downshift switch is not performing according to the preset parameters, a P2779 will be thrown

 

[Tonygw]

It was P2779 not P2279? But yes thats the code its throwing.
So it could be the transmissoin switch? mmm the mystery continues. I have bitten the bullet and booked it inot the MB specialist tomorrow. I dont have the time to investigate at the moment due to other commitments. I'll keep you posted as to what they find. Just hoping it isnt going to be to costly given the time of year it is and payday being in a galaxy far far away....

 

[CowleyStJames]

Do you have manual gearchange, ie, steering wheel paddles?
Be worth seeing if the car still changes gear manually, up and down.
Keep us informed. All adds to knowledge [emoji106]

 

[Tonygw]

Yes its a 7 speed auto with paddle shift. I left it in auto the morning when it threw the engine light. Also noticable down on power.
cheers

 

[Tonygw]

Hi guys sincere apologies the correct code was p2279 I think I was having an off day when I posted this originally. Anyway car is back from the Indy garage. Fault was a large split in the intercooler pipe. This was replaced and so far so good. Hope this helps anyone else suffering similar issues.. cheers

 

[Tonygw]

Are you sure it's not P2279?
That indicates an air leak has occurred on the "metered" side of the intake manifold. There is more air entering the intake manifold than the mass airflow or MAP (manifold absolute pressure) sensor would suggest.
If it really is P2779, then that's a transmission downshift switch fault.
That allows you to manually change down the transmission gear using either the manual shift gate on the gear shift, or the paddle shifters located behind the steering wheel. If the downshift switch is not performing according to the preset parameters, a P2779 will be thrown

Yep spot on p2279 cheers for noticing!!