Hi there,
Maybe someone can help here.
My car, Mercedes E Class, W212, 2010, E250 diesel.
Suddenly stopped on te road and I got it towed to my mechanic.
After testing with the computer, we got P008700 error, low fuel pressure in the system.
After many weeks of testing injector, high pressure fuel pump, replacing fuel filter, fuel pump and the relay beside the fuel pump, and replacing the ECU, nothing worked.
It will run for 10 to 30 min, then stops.
When we checked the coltage on the fuel pump, it was down to 3.5V
As a test, we bypass the relay the powers the fuel pump, ( the one beside it, underneath the back seat) with separate power that its only on when the ignition is on, and that got the engine running, no problem.
Has power, runs smoothly without any issues.
But I have a feeling that it could cause issues in the long run.
Question is, what exactly control the voltage going to the fuel pump?
Has anyone come accross this issue?
Regards,
Louie
Maybe someone can help here.
My car, Mercedes E Class, W212, 2010, E250 diesel.
Suddenly stopped on te road and I got it towed to my mechanic.
After testing with the computer, we got P008700 error, low fuel pressure in the system.
After many weeks of testing injector, high pressure fuel pump, replacing fuel filter, fuel pump and the relay beside the fuel pump, and replacing the ECU, nothing worked.
It will run for 10 to 30 min, then stops.
When we checked the coltage on the fuel pump, it was down to 3.5V
As a test, we bypass the relay the powers the fuel pump, ( the one beside it, underneath the back seat) with separate power that its only on when the ignition is on, and that got the engine running, no problem.
Has power, runs smoothly without any issues.
But I have a feeling that it could cause issues in the long run.
Question is, what exactly control the voltage going to the fuel pump?
Has anyone come accross this issue?
Regards,
Louie
Quote:
Originally Posted by Plutoe
whats your VIN
This is the VIN number of the car
CaliBenzDriver
Out Of Control!!
close
Today
- Join DateApr 2019
- LocationSilicon Valley
- Posts:11,921
-
iTrader Positive Feedback0
-
iTrader Feedback Score(0)
- Vehicle(s) I driveW212 MY'14 M276-3.5NA @75kMi
-
Likes:7,016
-
Liked:6,769 Times in 4,760 Posts
Quote:
Maybe someone can help here.
My car, Mercedes E Class, W212, 2010, E250 diesel.
Suddenly stopped on te road and I got it towed to my mechanic.
After testing with the computer, we got P008700 error, low fuel pressure in the system.
After many weeks of testing injector, high pressure fuel pump, replacing fuel filter, fuel pump and the relay beside the fuel pump, and replacing the ECU, nothing worked.
It will run for 10 to 30 min, then stops.
When we checked the coltage on the fuel pump, it was down to 3.5V
As a test, we bypass the relay the powers the fuel pump, ( the one beside it, underneath the back seat) with separate power that its only on when the ignition is on, and that got the engine running, no problem.
Has power, runs smoothly without any issues.
But I have a feeling that it could cause issues in the long run.
Question is, what exactly control the voltage going to the fuel pump?
Has anyone come accross this issue?
Regards,
Louie
You have a Direct Injected diesel with fault for low fuel pressure.Originally Posted by Louie54
Hi there,Maybe someone can help here.
My car, Mercedes E Class, W212, 2010, E250 diesel.
Suddenly stopped on te road and I got it towed to my mechanic.
After testing with the computer, we got P008700 error, low fuel pressure in the system.
After many weeks of testing injector, high pressure fuel pump, replacing fuel filter, fuel pump and the relay beside the fuel pump, and replacing the ECU, nothing worked.
It will run for 10 to 30 min, then stops.
When we checked the coltage on the fuel pump, it was down to 3.5V
As a test, we bypass the relay the powers the fuel pump, ( the one beside it, underneath the back seat) with separate power that its only on when the ignition is on, and that got the engine running, no problem.
Has power, runs smoothly without any issues.
But I have a feeling that it could cause issues in the long run.
Question is, what exactly control the voltage going to the fuel pump?
Has anyone come accross this issue?
Regards,
Louie
AtoZ got replaced without improvement until the tank pump 03.5V got directly connected then everything works.
What low and high pressures are available?
What's the mileage?
Any other chassis faults that impact CAN-C?
I wonder if tank pump uses a 3-phase controller like GDI low-pressure feed. Is sensor shot ?
CaliBenzDriver
Out Of Control!!
close
Today
- Join DateApr 2019
- LocationSilicon Valley
- Posts:11,921
-
iTrader Positive Feedback0
-
iTrader Feedback Score(0)
- Vehicle(s) I driveW212 MY'14 M276-3.5NA @75kMi
-
Likes:7,016
-
Liked:6,769 Times in 4,760 Posts
This confirms the low pressure is from a 3xPhase AC pump...
I really don't get how it can run on 12Volts DC??
Mercedes fuel Pumps were legendary for burnt connections from high currents - Double check for good measure in addition to priors.
I really don't get how it can run on 12Volts DC??
Mercedes fuel Pumps were legendary for burnt connections from high currents - Double check for good measure in addition to priors.
Quote:
AtoZ got replaced without improvement until the tank pump 03.5V got directly connected then everything works.
What low and high pressures are available?
What's the mileage?
Any other chassis faults that impact CAN-C?
I wonder if tank pump uses a 3-phase controller like GDI low-pressure feed. Is sensor shot ?
I don’t remember as it sat in the garage for 4 months looking for the fault. Originally Posted by CaliBenzDriver
You have a Direct Injected diesel with fault for low fuel pressure.AtoZ got replaced without improvement until the tank pump 03.5V got directly connected then everything works.
What low and high pressures are available?
What's the mileage?
Any other chassis faults that impact CAN-C?
I wonder if tank pump uses a 3-phase controller like GDI low-pressure feed. Is sensor shot ?
direct wire to the fuel pump worked but I have a feeling it’s not the right thing
Quote:
I already replaced that unit under the back seat, on the right hand side. Originally Posted by Plutoe
look to MB wiring diagram PE47.40P-2101DAC the 651.911 fuel pump is controlled by N118 fuel pump control mod---first remove all the BS wires you attached then check B4/7 fuel pressure switch then front SAM fuse f34 and rear SAM fuse f42 if ok then you have a faulty N118 fuel pump control mod(under R rear seat)----fyi there is no relay in the 651 fuel system----forget all the other HS
That's the feed I bypassed with direct current.
for the last 4 months, we checked and rechecked everything.
We are just missing something stupid
We are just missing something stupid
CaliBenzDriver
Out Of Control!!
close
Today
- Join DateApr 2019
- LocationSilicon Valley
- Posts:11,921
-
iTrader Positive Feedback0
-
iTrader Feedback Score(0)
- Vehicle(s) I driveW212 MY'14 M276-3.5NA @75kMi
-
Likes:7,016
-
Liked:6,769 Times in 4,760 Posts
Quote:
We are just missing something stupid
I think you're right:Originally Posted by Louie54
for the last 4 months, we checked and rechecked everything.We are just missing something stupid
hooking up an AC pump on DC is not the way forward.
Hook up a compatible scanner to troubleshoot what's wrong will help you stop replacing good parts for no progress.
Let us know when you're ready
MB World Stories
The Best of Mercedes & AMG
Explore
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
S-Prihadi
MBWorld Fanatic!
close
Today
- Join DateMay 2018
- LocationJakarta-Indonesia
- Posts:6,598
-
iTrader Positive Feedback0
-
iTrader Feedback Score(0)
- Vehicle(s) I drive2014 - W212.065 - E400 ( M276.820, 3 liter Turbo) RWD not Hybrid
-
Likes:1,465
-
Liked:6,543 Times in 3,952 Posts
This engine , its fuel pump at the tank is not 3 phase unit as per the diagram PE47.40P-2101DAC
It is a 2 wire pump. So traditional simple pump, with speed control PWM probably.
Attached N118 wiring
Need a proper scanner to see what is the fuel pressure ( B4/7 sensor ) as seen by N118.
The amperage and voltage of duty cycle of the fuel pump as read by N118 should be available if using Xentry .
Sorry, me have no experience with diesel fuel pump and not a 3-phase pump.
It is a 2 wire pump. So traditional simple pump, with speed control PWM probably.
Attached N118 wiring
Need a proper scanner to see what is the fuel pressure ( B4/7 sensor ) as seen by N118.
The amperage and voltage of duty cycle of the fuel pump as read by N118 should be available if using Xentry .
Sorry, me have no experience with diesel fuel pump and not a 3-phase pump.
Quote:
I dont have a scanner, my mechanic did all that.Originally Posted by Plutoe
There is something very wrong with you or your mechanics thinking----you used xentry to get the fault----all you had to do is double click the fault and you would see three very simple electrical tests to locate the faulty part--is it the sensor, fuses, fuel pump control module or the pump----what did you do!!!!
And I got desperate, after waitting for 4 months, and when I got a chance to get it to work, I took it, as I need to do the NCT (4 months waitting list) and it passed with flying colors
I know is not the right thing to do, the reason I am here asking experts, because I want to get to the bottom of it.
As far as I know, the mechanic changed the fuel rail line and the sensor.
