floobydust2

My daughter has a 2013 C250 Sedan. She recently started getting some P0002 codes and the car basically looses power. I've looked at freeze frame data and throttle position is around 87%, RPM ~4400, vehicle speed showing 62MPH. The odd thing is the fuel pressure is showing at 1191 PSI. It's happened a few times now, so it's a concern.
I decided to do some tests on my 2014 C250 sedan... using a Kiwi3 and DashCmd. I setup a fuel pressure reading gauge. Oddly it fluctuates from under 700PSI to over 2000PSI depending on operating conditions. I'm not sure if this is realistic or perhaps a scaling error for the generic OBD-II codes. Any clues on this one?
As the error only happens when she's accelerating more briskly, I'm leaning towards a fuel flow delivery problem, possibly the fuel filter. The car has close to 75K miles, but as she travels a fair amount, she has to stop for fuel in various places around the state, so it's possible she's gotten some dirty fuel.
I've scanned multiple parts sources but none list a fuel filter for the C250. Is it possible this is integrated into the fuel pump assembly in the tank? I intend to replace the filter and check the tank for any debris in the bottom... but prefer to have a new filter in hand before pulling the rear seat and digging into it. Any help/insight would be helpful.
Regards, KM

michail71

Ah, the old P0002 code. It is a common problem. I doubt it is a case of bad fuel.

My car has been in the shop for 10 days for the same thing. It has been doing it the entire time I've owned the car but has gotten worse. They were never able to reproduce it in the service center until just out of warranty. The first time it happened they did a software flash but it didn't help.

So I'm trying to see if I can get coverage. They diagnosed it now as the high pressure fuel pump failing.

There are some YouTube threads on the problem as well. Many people complain of getting the fuel filter replaced, the HPFP and other fuel system components replaced and it not fixing the issue.

floobydust2

Thanks for the quick reply. Yes, I saw the very long thread around this problem and the fact that it seems to be an elusive fix.

Based on the fact that it only happens under harder acceleration, I would tend to lean towards a fuel flow capacity problem, i.e., if you can't get enough fuel to the high pressure pump on the rear of the engine, it won't develop enough fuel pressure to supply the required amount of fuel to the engine.

Now that I have some baseline data from my 2014 C250, I'll do the same data collection from the 2013 C250 and see what the differences are. I still find it very odd that the fuel pressure is showing such a high measurement of over 2000 PSI and the fact that it fluctuates wildly by over 1300 PSI.

I'll be sure to post additional findings here.

Regards, KM

michail71

That's odd floobydust2. I see your reply in an email but it's not on here. Let me know what you find out.

** Edit **
Ok, now it shows. The forum changes must be introducing some bugs.

floobydust2

Okay, update... first, the high fuel pressure being shown by the scan tool is normal. The new direct injection engines require high pressure. I found some description on the Mercedes site about it. So, I configured DashCmd for an extra gauge to measure fuel pressure with a range up to 2500 PSI. I took my 2014 C250 for a run and noticed pressures upwards of 2100 PSI. I pushed it quite hard as well... it easily goes past the 2000 marker with moderate acceleration and is quite consistent. When releasing the pedal completely, it drops below 700 for a bit, but is usually hovering around 1000 or higher around idle. Even when the pedal is floored, the pressure sticks around 2100 PSI and the car just goes.
Next, same test in my daughter's 2013 C250. Everything is the same, i.e., idling and moderate acceleration. However, as soon as you really push the accelerator and hold it, the car accelerates quickly but only briefly. The fuel pressure drops after a couple seconds from 2100, the ECU cuts off the high pressure pump, MIL turns on and the fuel pressure drops below 100 PSI. It stays this way until you cycle the engine off/on, then the high pressure pump is operating again. Bottom line, this is a flow problem. It's completely consistent, As soon as I push it too hard, it reacts normally, then drops off quickly as the flow can't feed the high pressure pump to keep up with demand.
I'm going to contact the dealer tomorrow for a fuel filter as that is the most logical cause. As the problem has happened over time and gotten worse, it makes sense that the fuel filter has been clogging up over time. I'll post again once I replace it and do some additional tests. I just can't see this being the high pressure pump as it can maintain 2000+ PSI consistently as long as the flow requirements aren't too high.

michail71

Got your post in an email again but nothing here. Perhaps my reply will trigger it to show.

michail71

Yup, some bugs going on with these forum changes.

michail71

I hope in my case it is the HPFP as I've already dropped $1K on getting that replaced.

Perhaps ItalianJoe1 might have something to offer. He seems to know this issue. Although my dealer seemed to indicate this is a rare problem. Much like every other thing I've had fail.

floobydust2

Yes, the forum seems to lag, perhaps because I'm a recent member.
So, I checked my local dealer parts guy... turns out the filter is part of an assembly for the C250 which includes a pump and sensor. P/N is 204-470-02-94. At least I should be able to rule out the tank pump, filter and sensor with a single assembly replacement.
One other side affect from yesterday's test. If I perform the fast acceleration test in succession (i.e., cycle the key and do it again), the fuel pressure and ECU shutdown happens quicker, which tends to reinforce the fact that fuel flow is being restricted, as it's taking time to get enough fuel pressure from the tank.

michail71

That's the part I had wanted to be what was failing. Much less expensive.

The dealer said my car will be ready tonight which really means tomorrow.

floobydust2

Update: I ordered a new pump assembly and had to do some travel, so I didn't get around to it until a couple weeks ago. In any case, I replaced the pump assembly in the tank which is located on the right side. Quite simple to get to overall and the job took about 40 minutes in all.
Old pump assembly has a very dirty filter sock and also found some grass clippings in the assembly. Who knew... in any case, did a test drive and the car was significantly better. Before it would pop an error code almost immediately on full throttle acceleration and was consistent. Now, it took multiple runs and several shifts and only managed to get a few error codes.
Next, ordered the filter assembly (which is on the left side of the tank). Note: the filter assembly also comes with the pressure sensor. To replace it, you have to remove the pump assembly as the lines from the filter cross the tank to the pump. Be sure to tie a cord to the lines before you pull them through... makes it a lot easier to get the new lines across... as they go through a narrow opening which is hard to see or reach.
Entire job was just under an hour including reinstalling the rear seat assembly. Pretty trivial in general.
Test drive time.... put about 40 miles on the car and ran it pretty hard (started to rain) but managed numerous acceleration runs with full RPM range past 6400 and into 4th gear. No error codes so far, but more testing will confirm the fix once the weather is better. For now, this seems to have resolved the problem.

Nike_mirtchev

Hi floobydust,
I have exactly the same problem with my 2013 C250. I almost got into an accident. The local shop diagnosed it and are 99% sure that is the HPFP.
They are sending me to the dealer for more thurogh diagnostic. My car has 104000 miles, it is my daily commuter.
I have read your last post and it seemed whatwver you did worked. Could you please confirm this issue has been completely fixed.

Thank you,
Nik

dol4er

For serious issues, it's always better to visit the dealer. They are better prepared than indie mechanics, they have a real STAR which shows more information than any ODB and most of all there is a chance to hold them responsible for mistakes. Indie mechanics... whatever goes wrong... it's always not their fault.

ezshift5

I have a C250 coupe........and so far only the selling MB dealer has serviced the car (two 10k complimentary service visits included via MBFS).

Would the fuel pressure issue be sensitive to high odometer readings (over 100,000 miles)?

So far the beautiful little coupe has been without flaw (34000 miles).



ez

floobydust2

As of now, the problem has not come back.It's been driven at least 3-4K miles since the last post and no issues. I also checked the ECU for any codes recently and there none logged. In my view, it's fixed. With over 100K miles on the car, if the fuel filter has not been replaced, there's a good chance it's partially blocked and causing a flow restriction. Granted the fuel system on the W204 is a bit odd, but there's basically three parts to it: the fuel pump assembly (which has the sock filter on the bottom of the fuel pump), the fuel filter assembly (both of these are in the fuel tank) and the high pressure pump on the rear of the engine (driven from the intake camshaft). If you can't get enough fuel flow to the high pressure pump, you will get a failure under heavy acceleration, i.e., full throttle.
If you are experiencing the problem under moderate throttle settings, then you may indeed have a faulty high pressure fuel pump. Hopefully the Benz dealer can fully diagnose the problem accurately. good luck.

Regards, KM

USA 61

Turns out the high pressure fuel pump on my C250 is on backorder with mercedes USA and could take 3 months to replace the pump.

Car is under warranty and very frustrated.

Anyone else been told this?

Nike_mirtchev

Hi USA61,
I was able to order the High Pressure fuel pump from Fcpeuro.com. Shipped in 3 days.
The dealer told me the same thing, currently not available 6-9 months wait, lol.

Nik

USA 61

Nik:
Appreciate the response - the car is under warranty and MBZ can eat the cost - I am not buying a pump for the car. I wonder if there are superior parts to the stock part that the dealer can be pressured to purchase as an upgrade to this situation? I am not a car/engine guy so apologize for asking what might be a stupid question. These fuel pump parts appear available all over the internet as you say. Any idea where to find the upgrade so I can start becoming a very squeaky wheel at the dealer?

chilnviln

I've got a 2014 c250, 22K miles, broke down 300 miles from home back in Dec 2017. Still In the shop with the updated estimate of end of February for HPFP, and I'm driving their POS Chevy Cruze loaner car. Dealerships say if I have the car moved closer to home I will have to start the process over again because they will have to do their own diagnosis to find actual fault. If it ends up being the same issue the closer dealer will have to put in a new request for part and in turn be at the bottom of the queue. Any ideas on what can be done? Someone told be to get in touch with MBUSA to see if they can be of any help. Anyone have luck with that? Car is located in California if it helps.

Nike_mirtchev

Hi chilnviln,
Talk to the dealership if they buy the part from a different place or if you buy it and they reimburse you.
Www.fcpeuro.com has it for less then $700 with lifetime warranty. Or pelicanparts.com.
Worth to try.
Good luck!
Nik

FCPEuro

My stock is depleted as is every other vendor, to compound the issue they don't even have available stock in Germany

--Kyle

chilnviln

thanks for the update. I just pissed and hate making Mercedes payments and driving a chevy for my troubles....the 1.4 turbo doesn't even compare.
I know it's not strictly a Mercedes issue, but come on are the assembly lines only building 1 HPFP a day?

bullcharles1

I purchased a used 2013 C250 with 50k miles from Mercedes of Cary, NC on January 12. The check engine light came on and the car went in limp mode while merging onto the interstate literally 10 minutes after I took delivery. The vehicle has been at the dealer awaiting a new HPFP ever since. I just received an update that the part is on back order and may not be released until March. I don't know if this is the true date as they've sort of strung me along on the timing thus far. None the less extremely frustrating I've only been able to drive the car I purchased four weeks ago for one day.

bullcharles1

chilnviln

Still waiting....called this afternoon and the only two answers I can get from the service manager is "sometime in March" and "you need to talk to the MBUSA customer service."
Mind you my car has been at the dealership since December 10 and every time I inquired aboot an ETA I always received a different timeframe on when it would be there.

When talking with MBUSA customer service the only two answers I can get are "the dealer orders the parts so they should have an ETA" and "as a valued customer, call back when repairs are completed and
we'll look into a small gesture of goodwill for your troubles."

And as I write this I received a call from the service manager stating that he talked to the parts manager about the ETA with HPFPs and MB parts assist center says "ETA pending, will monitor order and advise
when parts begin shipping." I'm at a loss for words and ponder ever owning another Mercedes again....at this point I would gladly go back to Volvo.