Jon's first drivability issue - EGR System Related DTC

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jdcaples

Not Suitable w/220v Gen
I thought about putting this in NCV3 Write-Ups, but I thought it was worth putting it in "NCV3 Talk" since we can all talk about it.

This posting is about my first EGR System-related Diagnostic Trouble Code: 2511 in the Engine Control Module (ECM).

Highlights:
• Less than normal power
• Definitely not “Limp Home Mode”
• The Check Engine Light never illuminated
• Stopped Engine, Started Engine, Problem Fixed
• DTC Stored – System Tested – No Problem Found

Mileage: 23,400 miles
Year: 2007
Model: 2500 144" WB Cargo - 3L V6 diesel

The attached PDF details my driving experience, my thoughts, me snooping around with StarMOBILE using the Desktop Client and WiTECH, running the EGR System Test and my conclusion which is:

If you have an issue where you can't get past a certain engine speed, try parking, stopping the engine and after a few minutes, start up and continue on your way. There might not be anything that you can fix with economic or emotional reason.


View attachment Jon's First Drivability-EGR System-Issue.pdf

Key words: Power Loss, poor acceleration, restart fix it, EGR Positioning Error, DTC 2511


Comments welcomed. If I got something wrong, if I made a mistake, please let me know so we all learn. I ask some questions in the PDF regarding the EGR system test and what 5%, 10%, 50% and 80% mean..... If you know the answer, please post!


-Jon

PS: I don't think this is "Limp Home Mode," because I could drive faster and beyond 3rd gear than Limp Home Mode typically restricts.... but I could be wrong on this.....
 

72chevy4x4

Well-known member
I found in my suburban and some previous autos such as a 300zx, the tranny would not shift into OD until a certain temperature is achieved (which I think was time dependent NOT temp dependent).

does the Sprinter have such a feature?
 

qualityair

'09 144" Cargo
At first blush, I see a non-linear change in the mass air flow when the valve is at 80% or 50% compared to 0%.


Charles,
 

jdcaples

Not Suitable w/220v Gen
I found in my suburban and some previous autos such as a 300zx, the tranny would not shift into OD until a certain temperature is achieved (which I think was time dependent NOT temp dependent).

does the Sprinter have such a feature?
I don't know if the Sprinter has such a feature. I can say that I can hit all five forward gears at any temperature, at any time, under normal circumstances, and even today.... I felt the shifts from first - fifth.... just at "my normal RPM" driving range, not my attempts to drive like a normal person (2800+ RPMs).


-Jon
 
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jdcaples

Not Suitable w/220v Gen
At first blush, I see a non-linear change in the mass air flow when the valve is at 80% or 50% compared to 0%.


Charles,

After reviewing the screenshots, yeah, I see what you mean.

Is that releated to the mass air flow sensor reading? I wasn't watching that metric.

-Jon
 

folzag

Member
Jon, given you only noticed this DTC when driving unusually hard for yourself and given it went away after an ignition cycle, is it possible this has happened previously and you've never noticed? :)
 

jdcaples

Not Suitable w/220v Gen
Jon, given you only noticed this DTC when driving unusually hard for yourself and given it went away after an ignition cycle, is it possible this has happened previously and you've never noticed? :)
If it has happened before, it was recent. I scan it every 10 or 14 days just to keep an eye on things like my regeneration frequency, looking for DTCs that don't light up the dash board warning lamps.

-Jon
 

jdcaples

Not Suitable w/220v Gen
Jon,
I'm quite certain there are different levels of LHM available to the ECM. Just because all the gears are still in play doesn't mean that the computer hasn't selected some level of LHM.

I mentioned it in the LHM causes thread.
https://sprinter-source.com/forums/showpost.php?p=66366&postcount=11

FWIW. (I could be wrong.) AP/vic

I thought Limp was restricted access to 2nd gear or third gear and a top speed of 40. This morning, I got to 60... my RPM revs were just limited in rate of increase and at the top to 2200 RPMs or so.

Oh, and I have hit 75 before.... once or twice in the last couple of years.

-Jon
 

sprintguy

16+ yrs Master Commercial technician
Jon : here is a kinda cool test for the 2511 ; go into DATA DIAPLAY find sensor readings for : EGR cooler Temp, MAF (reading mg/stk) EGR valve %, O2 volts, and EGR throttle valve %. Now toggle rows so all reading are lined up, then go for a drive. Monitor this data, and report. What should happen is, as EGR % increases Mass air flow should decrease, Temp should decrease, and O2 readings should change (I believe increase). Another value to keep an eye on is the EGR throttle valve, that should change as EGR % changes. To much percentage on the EGR throttle valve is a good indication of the EGR valve is not opening to desired positon.

Carl
 

itasca2008

New member
Hi Jon

You pretty much experienced LHM for the first time in your Sprinter life! The vehicle shifts through all the gears but it has no power because turbo boost is shut off and the engine is not revving the way you are used too. If you have a ScanGauge II you can see this right away if you have MAP on display (what I always have, excellent indication how the engine is performing). If the engine is ok MAP goes up to about 35 or more psi if you stomp on it, the pedal I mean. If turbo boost is shut off MAP goes hardly up to 15 psi.

And another note: Besides of wearing out the EGR prematurely because of too much movement every time you shut your engine off the recall H44 is nonsense. I still have not done it but I clean my EGR every 10,000 miles. Works great I'm over 35,000 miles now. And in the near future I will follow Carl's recommendations and clean the whole EGR system.

Hope this helps.

Marcel in AB
08NJ
 
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cedarsanctum

re: Member
I could believe there are several stages of limp available to the engine. When mine did it, there was no light, but i could not accelerate and it wouldn't shift correctly. Turning it off did correct the limp mode, but not the cause. That was corrected by replacing the EGR valve. The trouble code i got was the same one.
Jef
 

jdcaples

Not Suitable w/220v Gen
First I want to thank everyone for taking the time to respond with thoughts.

For now, I'm going to retain the record of the DTC and not make any changes to the system or my habits. One event isn't enough to justify surgery, even with all the postings in the NCV3 area. I just don't think it's prudent of me to react just yet.

Further, I can't say that I'm all that interested in gathering the metrics Carl's cited,

  • EGR cooler Temp,
  • MAF (reading mg/stk)
  • EGR valve %,
  • O2 volts
and watching those metrics for an
  • EGR %cooler temp increase
  • Mass air flow and EGR cooler decrease with commensurate
  • O2 voltage changes

but my disinterest is rooted in laziness. I suspect another 2511 event, or any other EGR system code, would be motivating.

Monitoring the the EGR throttle valve deltas in contrast to EGR valve % changes seems like low hanging fruit.

I'll probably configure a StarMOBILE desktop client view with at least those two attributes, though, and report back if it happens again.

For those that have had EGR system parts replacement, or perform the procedures, what are the latest/greatest part number for valve, cooler and sensor?


-Jon
 

220629

Well-known member
I thought Limp was restricted access to 2nd gear or third gear and a top speed of 40. This morning, I got to 60... my RPM revs were just limited in rate of increase and at the top to 2200 RPMs or so.

Oh, and I have hit 75 before.... once or twice in the last couple of years.

-Jon
Jon,
Jon,
Here's some examples of the text from the post we started about LHM which made me conclude there are levels available to the ECM. Most are quotes from Doktor A. I think the sum of them indicate there are levels of limping.

https://sprinter-source.com/forums/showthread.php?t=7173

Transmission Sensor Readings

"First a few words regarding limp-home/shut down modes. Some (minor)
DTCs(failure codes) will allow the trans to resume business as usual
when problems go away on their own. More serious anomalies will shut
down all the internal solenoids and default to whatever gear you
happen to be in at the time. After you cycle the ign. key (or shift
into park) it will then go into a limp-home mode which is (usually)
2nd gear and reverse and a shut off of the TCC(torque converter
clutch). Typically a max. of about 3 cycles of the key will allow a
"temporary reset" to quasi-normal operation and after that, limp-home
will be permanent until the dealer clears the codes. Some failures
will not shut down all internal control solenoids. If internal
slippage is detected it may default to 3rd gear operation(in
limp-home). The transmission can even become totally disabled by
defaulting to neutral(!)."

Overheated Fuel

"The ECM will reduce engine power (limp) to prevent overheating of fuel."

The EGR Back Pressure Sensor

"To prevent damage to the turbocharger from overheating and/or overspeeding, the ECM monitors the exhaust pressure upstream of the turbocharger. At high exhaust backpressures, the speed of the turbocharger drops and consequently the boost pressure drops. The ECM adjusts the guide vanes in the turbocharger to regulate the boost pressure.
WARNING: If the exhaust back pressure is too high, the ECM switches to limp-in mode to protect the turbocharger. The limp-in mode can only be reset by restarting the engine."

BOOST PRESSURE SENSOR

"If the boost pressure sensor fails, the ECM records a DTC into memory and continues to operate the engine in one of the three limp-in modes."

Hope this does some good. vic
 
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abittenbinder

Doktor A (864-623-9110)
Don't confuse TCM limp home modes with ECM limp home modes.

For example, a particular TCM default shuts off all the solenoids on the valve body which allows only drive in 2nd gear and reverse. ECM default mode will essentially eliminate turbo boost.

There are other TCM defaults which eliminate all drive (can't really call that one a 'default', can you) and a slippage fault which will allow for 3rd gear only.

The ECM can also reduce power by reducing high pump output and revs. Engine torque reduction can be requested by ASR or ESP. Doktor A
 

220629

Well-known member
Doktor A,
Ah, the teaching continues. I didn't think to differentiate between the two computers having their own LHM capabilities. Needless to say I have figured out that all reduced power operation is not necessarily a computer requested LHM. It can be just a plain old mechanical or electrical failure.

That really makes me wonder why they didn't include a separate dash light or code to set the MIL and record when any LHM operation is set. It sure would make things easier for the poor operator to know what's going on. Think of Brucetheparishiltonfan driving on without knowing because he had no other experience of expected engine performance to draw upon. Overall at the least it seems kinda inconsiderate on the part of the MB designers/marketers. Maybe I expect too much.

As simple as they are to operate, these darn Sprinters really can be complicated beasts. (so said Captain Obvious). Thanks for helping to set me on the right track yet again. AP/vic
 

jdcaples

Not Suitable w/220v Gen
I hate to admit it, but my Sprinter's misbehavior actually crept into my dreams last night.

Logically I know that there's no evidence to suggest that I need to do anything. To support my "no action required at this time," idea this morning, I ran the same loop, driving like a normal person after having allowed the Sprinter to sit for more than 10 hours idle over night.... I can't replicate the problem.

I scanned the Sprinter when I got to work. No DTC (no surprise there).

I configured a WiTECH 10.01.22 template to watch the metrics Carl cited....

So I took some time during lunch and reviewed the DTC-based diagnosis and the non-DTC t-shooting stuff on Techauthority (attached).

There are two sections in the Techauthority content for DTC-based diagnosis that have info on 2511.

At first blush, they look identical. Maybe they are... I just wanted to cut-n-paste the info into a doc and make it a PDF. Each one makes references to other sections of the service manual content: DTC based diags, pre-diagnosis work, what to do if it's "intermittent." I figure my situation qualifies as intermittent for now....

So this coming weekend, if the weather doesn't threaten to soak me, I figure I'll start on page 18 of the attached PDF (Intermittent DTC) next Saturday just for the experience and to feel less, I don't know, passive about it.

All thoughts are welcomed....

-Jon
 

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Chandlerazman

Active member
Jon, I know the feeling of having the Sprinter creeping into dream territory. I was so distraught by the idea that my new van was rusting that I too have had it in my dreams. What a bugger it was. It had turned out to be "rail dust" rusting on the surface of the hood and horizontal surfaces. Stay positive. These complex machines will have a hiccup or two every so often :smilewink:
 
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