DEF Warning light and no momentum after filling

[Sprintersaurus]

My wife and I just bought a used 2014 Sprinter 170X with 58K miles on it. I got it home to Melbourne from Miami without a problem. But 2 weeks later, it starts up, but upon pressing the gas, the vehicle moves forward, but immediately loses momentum and begins creeping along at 1MPH. The dealership where we bought it told me the yellow "Engine" warning light was on because of upgraded headlights. I figured I would look into that since it sounded pretty lame. The "DEF" warning light came on during the drive from Miami, but it took me a while to figure out what it was. I only drove it a few miles (<10) during the 2 weeks before it stopped working. The Dash message reads ("Idle").

I am not a mechanic and not familiar with diesel engines, but I got some DEF fluid and put a gallon in the filler and it was full. That surprised me, because I expected it to be empty and thought that filling it up would fix the problem. I would like to try to resolve this myself. Any ideas on where to look for answers? Should I drain the DEF tank? Is that something I can do at home?

 

[Sprintersaurus]

I am exploring the possibility of it being the Exhaust Pressure Sensor, but am having trouble locating where it is! Newby problem!

 

[Sprintersaurus]

Okay. Finally found the sensor attached to the front of the Air intake under the hood. Thanks YouTube!!
I ordered a new sensor, but still do not know if this will work or not. Any suggestions. ( I feel like I am talking to myself so far! : )

 

[Hooligan2]

Probably need a Mercedes or Freightliner Sprinter shop to read the codes... Sounds like you are in "limp" mode, can have a number of causes, engine systems or DEF. Usually too many possibilities to just guess at cause or parts.. requires a MB capable scanner. Check engine light can also have many causes. Your 2014 Owners manual is available here. 2014 Sprinter

 

[sailquik]

Sprintersauras,
Is your Sprinter a 4 cylinder (OM-651 + 7G-Tronic transmission) or a V6 (OM-642 + 5G-Tronic/NAG-1 transmission).
As Hooligan2 suggests, you need to find an authorized Mercedes Benz Sprinter or Freightliner Sprinter dealer with the
full MB capable diagnostics.
They can run the full diagnostics and probably determine what sensors or emissions devices are causing your issues.
Not something you can DIY.
They will be able to determine exactly which genuine Mercedes Benz Sprinter sensors need to be replaced from
from the VIN # of your Sprinter.
They can also see if the bad sensor/device has been upgraded.
Hope this helps,
Roger

 

[Sprintersaurus]

Sprintersauras,
Is your Sprinter a 4 cylinder (OM-651 + 7G-Tronic transmission) or a V6 (OM-642 + 5G-Tronic/NAG-1 transmission).
As Hooligan2 suggests, you need to find an authorized Mercedes Benz Sprinter or Freightliner Sprinter dealer with the
full MB capable diagnostics.
They can run the full diagnostics and probably determine what sensors or emissions devices are causing your issues.
Not something you can DIY.
They will be able to determine exactly which genuine Mercedes Benz Sprinter sensors need to be replaced from
from the VIN # of your Sprinter.
They can also see if the bad sensor/device has been upgraded.
Hope this helps,
Roger

It is a V6 Engine. I just ordered a diagnostic reader and should have it in a couple days. I also found and downloaded what I think are the error codes. The reader is blue tooth and it will tell me the error code and list potential problems and then links to potential solutions. Not perfect, but it gets me a pointer. I am going to try the computer and see how far it gets me, but in the end, I will take your advice and take it to the Dealer for a full diagnostic. I was just hoping to drive it the 10 miles instead of having it towed.

Thank you VERY much for your advice! Sailquik and Hooligan2!!

jon

 

[sailquik]

Sprintersaurus,
If your Sprinter only has 58K miles on it, there may be some of the 100K Emissions Warranty left.
Since the problem seems to be with the SCR (Selective Catalyst Reduction) system that should be under the emissions warranty to
100k miles.
The "dealer" that told you the yellow light was something to do with the headlights should pay for the tow to the MB Sprinter
(Make sure it's an authorized Sprinter dealer, not just a Mercedes Benz Car dealer) shop.
I wouldn't buy any more parts based on what your bluetooth diagnostics tells you as they almost for sure do not have the
full MB diagnostic capability.
By the time you buy a few parts that don't fix the issue, you could easily pay for the diagnostics and the repair.
Hope this helps,
Roger

 

[Sprintersaurus]

Sprintersaurus,
If your Sprinter only has 58K miles on it, there may be some of the 100K Emissions Warranty left.
Since the problem seems to be with the SCR (Selective Catalyst Reduction) system that should be under the emissions warranty to
100k miles.
The "dealer" that told you the yellow light was something to do with the headlights should pay for the tow to the MB Sprinter
(Make sure it's an authorized Sprinter dealer, not just a Mercedes Benz Car dealer) shop.
I wouldn't buy any more parts based on what your bluetooth diagnostics tells you as they almost for sure do not have the
full MB diagnostic capability.
By the time you buy a few parts that don't fix the issue, you could easily pay for the diagnostics and the repair.
Hope this helps,
Roger

I ran the diagnostics and it tells me the following.

Under Confirmed Trouble Codes:
UD10E Lost Communication with Redundant Control Module
P2201 NOx Sensor Circuit Range/Performance Bank 1 Sensor 1

Pending Trouble Codes:
P2454 Particulate Filter Pressure Sensor "A" Circuit Low

Under Permanent Trouble Codes
UD10E Same
P2201 Same

I was trying to avoid a tow charge. Can I delete these with teh diagnostic computer and make a single 10mile trip over there? Or is that not a good idea?

 

[Mike DZ]

Deleting the codes won't necessarily change the way the vehicle is acting. If you delete the codes and make it to a dealer, one of the first things the tech will do is look for codes to help with diagnostics

 

[elemental]

My wife and I just bought a used 2014 Sprinter 170X with 58K miles on it. I got it home to Melbourne from Miami without a problem. But 2 weeks later, it starts up, but upon pressing the gas, the vehicle moves forward, but immediately loses momentum and begins creeping along at 1MPH. The dealership where we bought it told me the yellow "Engine" warning light was on because of upgraded headlights. I figured I would look into that since it sounded pretty lame. The "DEF" warning light came on during the drive from Miami, but it took me a while to figure out what it was. I only drove it a few miles (<10) during the 2 weeks before it stopped working. The Dash message reads ("Idle").

I am not a mechanic and not familiar with diesel engines, but I got some DEF fluid and put a gallon in the filler and it was full. That surprised me, because I expected it to be empty and thought that filling it up would fix the problem. I would like to try to resolve this myself. Any ideas on where to look for answers? Should I drain the DEF tank? Is that something I can do at home?

If you bought it used but at a dealer, and you have owned it only about a month, I would try calling the dealership and asking them what they are going to do about it.

With respect to the codes, are you sure it's not showing a U010E, "Lost communication with the reductant control module" (not redundant)? Reductant in this case refers to the Diesel Exhaust Fluid (DEF) which is used to reduce the nitrous oxide in the exhaust. The other message you are showing is calling out a fault with a NOx sensor, which is what measures the amount of NOx (nitrous oxides) in the exhaust to help control how much reductant (DEF) to use as part of the Selective Catalytic Reduction (SCR) system.

Those two messages together indicates the SCR/DEF system isn't happy, and although it's possible is just went *sprong* immediately after you bought it, it's also possible (perhaps even more likely) it was already faulting before they sold the van to you. If that system is still under warranty from MB (as part of the emissions system) then getting it repaired won't cost you. If the dealer who sold it to you has any kind of 30/60/90 day warranty on used vehicles it will make it even easier to get the dealer to look at it. Does Florida require limited warranties on used vehicles? Without warranty support from either the dealer or MB you might be looking at hundreds to thousands of dollars to repair (I am not an automotive technician, and I wouldn't try to guess the repair with this limited amount of information even if I was). It's not a terrible situation, but you might have to be assertive to get the repair covered.

 

[irvingj]

There have been numerous threads about pre-2016 V6 Sprinters having older version NOx sensors that have failed. Our 2015, for example, came with version 2 of these sensors; they failed and were replaced with version 5, apparently the current (and still working) version. In our case, this happened at 18K miles.

When they fail you will get various "LOW DEF" and "X STARTS REMAINING" messages. Limp Home mode (LHM) a definite possibility. Perhaps that's what's happening in your case. As soon as possible, you might ask to verify which version of these sensors your 2014 is equipped with.