bamaxrt

Greetings! My daughter has a 2012 C250 with a 1.8 L gasoline engine, "Blue Efficiency." She tells me that she had a difficult time getting it started recently, but after about five tries, it started-up. Now, the car has been parked for a day or two and when I put the key in the ignition, it says, "remove key from ignition." Initially, I thought she had a bad battery, so I hooked it up with jumper cables to a known good battery, and no change. Absolutely NOTHING happens when I turn the key. Thus, I got out the OBD reader, and I got two codes, P0002 - Fuel Volume Regulator Control Circuit Range/Performance -and- U0028 - Vehicle Communication Bus A. P0002 reports as "Confirmed." U0028 reports as "Permanent Confirmed" and a freeze frame gives the following additional information: Absolute Throttle Position 14.5%; Manifold Absolute Pressure 28.6 "Hg; Ignition Timing Advance 2.0 deg; Short Term Fuel Trim Bank 1 - 0%; Long Term Fuel Bank 1 - 0%; Short Term Secondary O2 Sensor Fuel Trim Bank 1 - 0%; Long Term Secondary O2 Sensor Fuel Trim Bank 1 - 3.1% (Considering Engine is Off, shouldn't this be 0%?); Absolute Fuel Rail Pressure 187.1 PSI; Relative Throttle Position 4.3%; Commanded Throttle Actuator Control 3.9%; Throttle Position B 14.1%; Accelerator Pedal Position D 5.5%; Accelerator Pedal Position E 5.5%; Commanded EVAP Purge - 0%; Commanded Equivalence Ratio (Rich/Lean) 0.999; Fuel Level Input 39.2%; Control Module Voltage 12.235 V. I was not pressing on the accelerator when I ran this check. I have checked all of the fuses associated with the fuel pump, and they are all in tact.

Is there one unifying problem that could cause all this? If so what? Is it a problem that an advanced amateur (i.e. me) can fix? Where are the pertinent parts located in this engine?

Thanks very much for any input!

ruinedw204

Hi bamaxrt,
I can tell you that the code P0002 is because of a failing High Pressure Fuel Pump. As for U0028, I am not familiar with this issue.
A remanufactured HPFP can run you $400-600, make sure you check all of the MB Parts websites as there are several that all look similar but with different prices.
I had mine changed two days ago and my issues finally went away. Labor can be expensive, the shop that did mine charged me for 2 hours because they didn't know what they were getting themselves into. It took them 5 hours. It's a difficult job because it's at the back of the engine, facing the driver. I suggest you take a look at the following threads: C250 - Accelerated and car suddenly lost power, C250 Fuel problem, and High Pressure Fuel Pump replacement.
The part numbers involved in the repair are the following:
"Here are the parts list as stated on the repair invoice. (part # : description)
271-070-37-01-80 : High-pressure pump core w/ charge
004-997-20-90 : Hose clamp
271-096-02-80 : Gasket
271-096-01-80 : Gasket" (member: newdrive, 12-31-2018 in the thread "C250 Fuel problem").
If anyone has any advice on U0028 please advise bamaxrt.

bamaxrt

Thank you so much for this really detailed reply! I was worried that might be the issue.

bamaxrt

So I can see where this pump is, but does anyone know of an online guide to changing it out? I'm daring!

bamaxrt

I keep coming up with more questions here...I read on one of the referenced threads that one needs to be sure the ECU and fuel pump software are up-to-date. Is there any way to know if this is the case?

onehighfocus

So did you ever get around to swapping out the HPFP? Im about to take it on but wasn't sure about the sprung clamp.
Per Ruinied's post, its 004-997-20-90 - Fuel Line Hose Clamp - 14.5-15.5 mm Range... Hopefully that's correct.

ruinedw204

Hey, I ended up having a shop replace the HPFP. Cost me around $350. I'm on a Stage 2+ E30 Tune pushing close to 260bhp. I replaced the HPFP back around April with a re manufactured HPFP. I have not had any P0002 issues since that day. I redline the car when I do pulls and drive the car moderately hard often.

Again, everyone is trying to avoid replacing their HPFP when they get P0002 because they think it's something else that's wrong with the car. Countless hours of research have been done on the subject, it is most certainly the HPFP.

onehighfocus

$350 just for install labor? That seems somewhat reasonable. Yeah, you would think with as many of these that have been swapped out, someone would have done a comprehensive DIY how to...

I actually just finished mine and got it done in just under 2 hours without removing the intake manifold. Dealing with that dang low pressure line Clic-R clamp is the main pain followed by lining up the drive dogs on the pump would be next.

I did remove the intake filter (T25)and the oil filter housings to make room to work. Getting everything unbolted and free is no problem...

I used a E10 with long extension to get the wire connector bracket off and an 8mm ratcheting open end wrench for the pump to block bolts. It's getting the low pressure line into position where you can get the clamp off is where you gotta turn on puzzle solving mode.

Good thing the low pressure line has some slack on it. With the high pressure hard line disconnected, you can tip, twist and turn the pump into a better position. I was able to get the rubber line to come under the fixed hard line (moving towards the oils filter) and up over the hard line which made dealing with the clamp much easier.The spring clamp is actually reusable if you have the proper tool to unlatch it and then re-latch when installing.Clic-R is the brand name and the pliers can be found on Amazon or ebay pretty cheap.

Once that Clic-R clamp is opened, I did struggle a bit pulling the hose off the nipple. Its just a tight space and hard to get a grasp on it. I guess you could just yank the pump up and away but I didn't want to risk ripping the line or disconnecting it from whatever it may be hooked to under the intake manifold.

Now just put everything back in exact reverse order, including having the pump in that same position it was in to get the clamp off. Slip the rubber line back under the hard line and tip, twist and turn the pump back into its resting position ready to engage.

*I waited until the pump was bolted to the block to tighten on the hard line.*

My OEM re-manufactured pump came with the black "Iron Cross" adapter stuck to the pump with some heavy grease. I opted to take it off the pump and stick it to the engine side with that heavy grease. Cant say for sure if its better either way.

Not sure what ItallianJoe1 meant by setting the crank to 57 degrees as my pulley is only marked up to 30. All I did was stick my finger in the hole (giggity) and turned the crank (27mm bolt) till it felt like it was in the right position. Perhaps if you have two people, you can have one hold the pump in position with another turns the crank until it drops in.

Then just tighten all the bolts back up (don't forget the high pressure hard line) and you're done.