Mercedes: c220 cdi sudden turn off, mercedes c class, tank pumps

Question
QUESTION: hello sir, i really need your help. i have mercedes  c-class
220cdi. i have a problem which the local dealer wasn't able
to find with the diagnostic tools. the suddenly turns off
(while driving and then it can't be turned on for 5 min al
least). i don't know if it has anything to do with it, but
sometimes it make strange noise while trying to start and
sometimes the screen shows "under voltage"

thanks in advance,
Omry Oz

ANSWER: Omry,
Questions to start....
What year model is this vehicle? 8, 6 or 4 cylinder? Automatic or strait drive? How many miles? When was the battery replaced last? Have you changed any components before the stoppage?
When were the fuses removed and or changed last?
Have you ever cleaned under the hood using water and cleaner?
When was the Oil last changed and what is the oil level?


---------- FOLLOW-UP ----------

QUESTION: first i want to thank you for the super fast reply.
it's a 2001 4 cylinder model, automatic drive. it use to be a taxi so it has 200K miles . the battery it's pretty new, the oil was changed in the last threatment and i can't recall a water under the hood cleaning.
some sensors were replaced like the Y5 and someother (i don't really know about it)

thanks again,
Omry

Answer
This sounds like some sort of electrical high resistance short. I suggest you begin by cleaning as many terminals as possible. The battery post. The fuse holders. If you are using the knife type fuses they are not as likely to have corrosion. If I has the ceramic cylinder bullet type, they are notorious for corrosion. There may also be an over voltage relay with a fuse in the top take it out.
If the vehicle has an in tank fuel pump, it can be over heating. In tank pumps need to me kept  submerged for cooling. If lots of time is spend below 1/8 tank then the pump can over heat and shut off.
There is also a fuel pump relay that can go bad.
When the vehicle quits, you can check to see if it is fuel or electrical by removing the air cleaner. Spray  a little car starting fluid into the intake. If it stars and stops almost immediately, then you have a fuel supply related problem. Bad pump, bad pump relay most probably.
If it does not fire off at all, then you may have an issue with ignition. Bad coil, etc.
Good luck
Rob