Hello
i have ml 350 bluetec 2011 and i have the error code
11C300 The upper limit value of component B4/6 rail pressure sensor has been exceeded. I have already replaced the pressure sensor injectors fuel pump but nothing.
fuel pump crack at 1500 rmp
help please

my problem is that my car has check engine light on and my high fuel pump start rattling when i try to accelerate.
also when i pull out the cable from the rail sensor everything is ok the rattling noise stop .

this car is making me crazy

I would first test the high pressure pump output with mb star. Its a short test, rpms are increased till certain pressure and the car runs for about a min and shows how steady the pressure output is.

Regulating the rail pressure is the job of pressure regulator.
Don't see it addressed?
Got to love members who drop couple grands in parts, before asking for advice.

i have changed rail sensor couple of times still hearing that noise after 40 sec engine start

I have y74 pressure sensor below normal Can this couse rattling to fuel pump ?
hello

Why do people tend to blame the sensor? The sensor is telling you that there is a problem with fuel pressure. We say "don't shoot the messenger!"

please what do you suggest?

I suggested you run this test.

Judging from the screen language (Italian ?) - English is not OP 1st language and I see now that some misunderstanding might be due to that.
1st the test calls for full engine operating temperature, what was not met during the test.
Now I see the fuel pressure is too low, when "exceeded" in original post suggest it as too high.
Than as Honda suggest - focus on high pressure test, not on general test.

yes the temperature is not correct because test was in the morning 3 min after car started.
i will do the HP pump test and share here the results
thanks a lot