New (2005) Sprinter problems: fuel rail, fuel solenoid, Codes P008, P2601

marcusbest

Active member
After months of searching, I finally bought a Sprinter. The price was right, one owner, 153K miles. 2005 140 cargo van. I drove from Taos to Phoenix on my motorcycle, bought it, loaded up the motorcycle, and headed back to Taos. I took a bit of a risk with the purchase. The Sprinter was in limp mode, couldn't get over 60mph, and I was told the codes read "high and low fuel pressure". But the price was low enough that I was ready to spend a few thousand on repairs and still feel like I got a good deal. Driving back to Taos, I almost made it to Santa Fe (60 miles from home) and after refueling, the van wouldn't start. AAA tow truck to Santa Fe, in the hands of competent mechanics (I believe). They ran tests and made recommendations, resulting in: serpentine belt replacement, replaced all glow plugs, new fuel pump. Now the sprinter runs, but still in limp mode. After diagnosis and other testing ($$$), codes P0088 (high fuel pressure at the fuel rail) and P2601 (low pressure at the fuel soledoid) show up. These are probably the codes that have been there for a while. Also, they found a failing turbo resonator (boost pressure leak). They are quoting $1630 parts and labor to replace the rail and solenoid :cry:. I have already bought a Dorman turbo resonator replacement already. I was prepared to sink some cash into this sprinter, and I want it to be tip top mechanically before I start converting it into a camper, but am I on the right path here? Or is this a rabbit hole that may empty my bank account?
 

Midwestdrifter

Engineer In Residence
Are you DIY savvy? If so the T1N is not bad to work on. I would suggest getting the basic tools to do the work yourself.

What tool was used to get those codes? 0088 does not show in the official fault code guide, and 2601 shows as a TCM power supply fault.

HP pump failures are rare. High and low pressure codes usually point to a failing injector, or bad rail solenoid.

Replacing the rail assembly is not technically challenging, and good used units can be had. millionmilesprinter sells used and new parts, and ebay has them sometimes.

If you own a T1N the first thing you need is a good scan tool that is sprinter compatible. Autel MD802 or 808, MBII are good. They will pay for themselves.


Various manuals and guides are here. This includes the fault code guide, and the troubleshooting guide which will list many of the faults, and detailed steps to fix.
http://diysprinter.co.uk/reference/

The good news is that your van likely only has a minor fuel system problem. The engine and trans are likely in great shape. With good maintenance you can expect to get another 150k from the drivetrain.
 
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marcusbest

Active member
Are you DIY savvy? If so the T1N is not bad to work on. I would suggest getting the basic tools to do the work yourself..
I am a pretty good DIYer, and this project would be a good start to familiarize myself with the mechanics of the van. I'll do some more research on parts and the work required. I think I read on this forum that the rail solenoid should not be replaced separate from the rail because it is tuned in the factory to the rail, so they should be replaced together. I got a mopar part from the mechanic that seems to be only the rail (5137290AA). Is there a separate part number for the solenoid or a part number for the matched pair?

What tool was used to get those codes? 0088 does not show in the official fault code guide, and 2601 shows as a TCM power supply fault.


If you own a T1N the first thing you need is a good scan tool that is sprinter compatible. Autel MD802 or 808, MBII are good. They will pay for themselves.
I don't know what tool was used, but I can find out, and I am planning on getting a scan tool myself.
 

marcusbest

Active member
I just looked on millionmilesprinter and they have the fuel rail (sensor included) for $476.94, WAY less than anything else I've found. Thanks for the advice Midwestdrifter!
 

Midwestdrifter

Engineer In Residence
From what I understand, the unit is always sold as complete. So rail always comes with solenoid.

I hope you asked for your old fuel pump back. That would be a good spare, seeing as they probably shotgunned some parts at it on your dime...

You will find that many shops don't even bother logging live data, they just read the codes and swap the most likely parts. This is not very effective on Common Rail diesels, as they have a very tightly controlled interconnected control scheme.
 

OffRoadRy

Member
I had a similar issue recently, although my code was P0090. As midwest mentioned, the autel MD802 is what I used to diagnose. You will need a scanner like this, I have an '05 2500 and it's already paid for itself. I think it cost me $160 on eBay.

So, the issue I had recently was a no start issue. It would crank but not start. I was driving on the interstate when it suddenly stalled. Wouldn't restart. It was towed and assessed by mechanics at nearby shop. Their code reader was not hinting at the real problem. But after I got the autel 802 I was able to pull the code and the guys on this forum pointed me in the right direction. In the end, it was the fuel rail solenoid. As mentioned, with this year sprinter you have to buy a whole new fuel rail and replace it - if that is indeed your problem. I got a used fuel rail for my model year on eBay for $180. Replacing it took about 1 hour. BUT, I do feel like if it was your fuel rail solenoid you would not have limp mode - it just wouldn't start. Replacing the fuel rail isn't too bad if you you're mechanically inclined. You will need a set of metric sockets and wrenches, and the e torx sockets for the crazy mercedes bolt heads. I replaced the hose clips on fuel rail with hose clamps and that was easy and worked great.

After replacing the fuel rail (with solenoid at the rear, which was the actual problem) the DTC went away. BUT, it still wouldn't start. Then I noticed fuel leaking and pooling under engine. The rear of the injector gallery in the head has a hose that drains to the ground. I did not properly tighten one of the fuel lines to injector 2 or 3, which caused fuel to leak during cranking. Once that was tightened up the engine fired right up and it's been running great since.
 
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Midwestdrifter

Engineer In Residence
The failure mode on the rail solenoid can cause different symptoms. If the seal deteriorates badly, the rail won't be able to build pressure at all (no start). If its marginal, or sticking, it can result in erratic pressure, causing high and/or low pressure codes, as the ECM tries desperately to get the pressuring in spec.

An injector that is sticking, and not injecting regularly can cause erratic fuel pressure as well. Usually this will result in poor running, and rough idle.
 

autostaretx

Erratic Member
The "couldn't go over 60 mph" screams "leaky resonator" at me. (been there, had that).

Pop in the Dorman (2 bolts, one hose clamp and 30 minutes .. move the old turbo-side O-ring to the Dorman or get a new one) and see if that symptom disappears.

Next step: buy a ScanGauge II (or similar) ... it will give you live readouts of stuff like MAP (manifold absolute pressure) ... what the turbo system is producing. It will report IAT (intake air temperature... the temperature *after* turbo and intercooler ... the temperature of the air that's actually going into the cylinders (and whose sensor fails at times) ... normal values are about up to 40 F higher than ambient temps.
It can also read the P-codes of OBD-recognized faults.

good luck
--dick
 

marcusbest

Active member
What tool was used to get those codes? 0088 does not show in the official fault code guide, and 2601 shows as a TCM power supply fault.
They used a Maximus 2.0



I hope you asked for your old fuel pump back. That would be a good spare, seeing as they probably shotgunned some parts at it on your dime....
The mechanics told me they tested the fuel pump and that it was showing signs of wear and not creating ideal pressure. But they still have the part and I'll keep it as a spare. I'm guessing it could've gone many many more miles before replacement was necessary.

So, the issue I had recently was a no start issue. It would crank but not start. I was driving on the interstate when it suddenly stalled. Wouldn't restart. It was towed and assessed by mechanics at nearby shop. Their code reader was not hinting at the real problem. But after I got the autel 802 I was able to pull the code and the guys on this forum pointed me in the right direction. In the end, it was the fuel rail solenoid. As mentioned, with this year sprinter you have to buy a whole new fuel rail and replace it - if that is indeed your problem. I got a used fuel rail for my model year on eBay for $180. Replacing it took about 1 hour. BUT, I do feel like if it was your fuel rail solenoid you would not have limp mode - it just wouldn't start.
The van was on limp mode for 450 miles. Then I stopped at a gas station, and it cranked fine but wouldn't start after that. After the work the mechanics did (not touching the resonator or the fuel rail) it runs again, but still on limp mode.

An injector that is sticking, and not injecting regularly can cause erratic fuel pressure as well. Usually this will result in poor running, and rough idle.
The mechanics were fairly confident that the injectors are fine. The engine is smooth running at idle and through acceleration.

The "couldn't go over 60 mph" screams "leaky resonator" at me. (been there, had that).

Pop in the Dorman (2 bolts, one hose clamp and 30 minutes .. move the old turbo-side O-ring to the Dorman or get a new one) and see if that symptom disappears.

Next step: buy a ScanGauge II (or similar) ...
--dick
I get the Sprinter back early next week and will start by installing the Dorman resonator and ordering a scanner (either a Scanguage II or autel md802).

Then if necessary, order a fuel rail and install it.

I'm really looking forward to getting to know my new Sprinter and also really looking forward to spending lots of time on this forum picking your brains and learning from all of you. You've already been a huge help. Thank you!
 

DRTDEVL

Active member
I bought a Sprinter in PHX with similar issues. P0088 was the cause for the LHM.

When it doesn't start, try unplugging the pressure sensor on the front of the rail. Does it start now? It wil sound funny, but drive it. It should be able to reach 65 or so, just a hair faster than before. If so, its the same issue.

Mine turned out to be the fuel volume control solenoid on the injection pump. Simple enough, but damn near impossible to diagnose without Sprinter-specific knowledge. In chasing that down, I replaced the rail, the injectors, and the lift pump, but it was in limp mode for the first 4 months of ownership. I finally found a competent shop here in Las Cruces that worked on all the FedEx trucks, and he found the problem within minutes, since he had seen it before. I replaced the solenoid when it arrived, and the van has been running great ever since (aside from issues with the cheap re-man injectors that required a couple fixes along the way, the time the turbo blew, and the issues that arose after my driver hit a deer).
 

Woodythesprinter

New member
I'm really looking forward to getting to know my new Sprinter and also really looking forward to spending lots of time on this forum picking your brains and learning from all of you. You've already been a huge help. Thank you!
Thanks for posting ! Always good to learn stuff before it happens on the road .!
 

marcusbest

Active member
So I received a new fuel rail from MillionMileSprinter (thanks again for the excellent customer service Joel!) and prepared to install it. Before doing that, I did the injector leak off test that Joel described. I didn't know what to make of the results: no diesel in any of the tubes, but thought it could be indicative of a faulty fuel rail. After putting everything back to original, I tried DRTDEVL's recommendation and tried starting with no luck.
I bought a Sprinter in PHX with similar issues. P0088 was the cause for the LHM.

When it doesn't start, try unplugging the pressure sensor on the front of the rail. Does it start now?
So then I went ahead and replaced the fuel rail. Still will not start. I checked the fault codes and there were two new codes, P0341 Camshaft sensor, and P0193 Fuel Rail Pressure Sensor Circuit High. The original P0087 and P0088 were still there. I guessed that the P0341 Camshaft sensor fault came up because I had unplugged the sensor for the leak off test.

I then cleared the active trouble codes and tried to start again. Nothing.

A little more info:
I am using an inexpensive OBDII Wifi scanner and the OBD Fusion app. This may be the point that I should take the sprinter to a shop with a professional scanner and a professional mechanic, but I live in a small town, and the nearest mechanic with Mercedes diesel experience is 1.5 hours away, so I'm trying to do as much as I can with your help before going that route.

Thanks again to all!
 

Midwestdrifter

Engineer In Residence
MD802 or 808 from autel is a good sprinter compatible scanner. That will provide sprinter specific codes, which may be of more help. What is your fuel pressure when cranking now?
 

marcusbest

Active member
I ordered an Autel MD802, and it should arrive Friday, so I can post cranking fuel pressure readings then. OBD Fusion doesn't give me that info.
 

marcusbest

Active member
OK. I got my Autel MD802 in the mail. I have not updated the software yet (I am a Mac user and it's Windows only). I ran a generic OBDII scan and the scanner picked up the low fuel rail pressure DTC. And the FRP (Fuel Rail Pressure) reading during cranking was . . . . . . 62.4 psi. I'm not sure if I'm reading the thing right; I may need some time to work out the kinks. But my understanding is that this pressure should be at least 2500 psi to start and should really be around 3600 psi. I am guessing the next step should be a low pressure fuel pump test (14-4 in the service manual). Also came across this page that could be helpful.

Keep in mind that 100 miles ago, the shop I took my Sprinter to replaced the fuel filter and the fuel pump. I assume they replaced the low pressure pump because the high pressure pump looks like it's been there for about 14 years. I'll be giving them a call on Monday to clarify a few things. . .
 

DRTDEVL

Active member
I'm hoping someone will tell me I need to replace a $20 sensor to solve the problem.

anyone. . . ?
Nope. We need more info.

You have 64 psi when cranking, that's your low pressure (in-tank) pump at work. Where is the high-pressure feed going? This is where we need more info, like the results of a successful injector leak-down test.

Since you seem to have no pressure building in the high pressure pump, this is where I would eliminate any potential problems first.

I'm leaning toward a failed fuel volume control solenoid, but that's no guarantee (and it's MB, so it's not $20, either).
 

marcusbest

Active member
I did an injector leak-down test before I replaced the solenoid and there was no fuel in any of the tubes. This was before I had the Autel to indicate the fuel rail pressure, but I'm guessing the pressure was too low to produce a valid test. I'll do some research on the fuel quantity control solenoid you mentioned.
 

marcusbest

Active member
Hmmmm. According to this post, the fuel quantity control valve doesn't even come into play for the first 30 seconds after the engine starts.
 

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