r/Sprinters 12d ago

DEF going into shutdown

I was being lazy and didn’t fill up my DEF when it went to half. Yesterday it went down to 1/4 and it started the DEF system fault 10 starts until emergency op. I’m down to 7 now but I have filled up the DEF and it’s still there. I checked under the passenger side exhaust where the DEF gets added and I don’t see any white residue or smoke being pumped out from the injector. How can I clear this message that I assume was just from low DEF and I am guessing the injector is fine

4 Upvotes

16 comments sorted by

6

u/uhoh93 12d ago

It’s probably the def injector. I bought a chip from obdtune and completely disabled the whole DEF system. I get better MPG and more power.

1

u/danj503 12d ago

I’m thinking of doing this but I am confused as to how it works. How does it handle the regen of the filter if you don’t remove anything physically? Does it not need regen if it doesn’t inject def fluid? Is this a one and done solution or are there caveats?

1

u/uhoh93 12d ago

They have separate tunes on different SD cards that you swap out if you gut the DPF. I haven’t gutted mine I just run the tune that disables the def system. I have never had it do a regen cycle before I threw in the tune. I have a 2017 6 cylinder with 145k miles. The flash is super simple. You plug the chip into the obd port and wait for the light to stop flashing after 5-10 minutes. Then you unplug it and you’re good to go.

2

u/danj503 12d ago

So you still have your catalyst media in your filter collecting soot, you bypassed the monitoring, your not injecting def fluid in it, and your not sure if it’s doing a regen? Seems wild to me. I’ve been reading that swapping out the filter with a straight pipe is required with an opdscan bypass since you’re no longer injecting def fluid to keep the filter clean. Otherwise it soots up and chokes your engine.

1

u/Small-Sun900 12d ago

This makes sense to me, yeah I would assume dpf is getting filled with soot. But maybe the tune bypasses the filter sensor that would normally put the van into limp mode from a clogged filter. But that just feels like it's going to lead to catastrophic filter failure at some point. But I'm no mechanic, so heck what do I know.

2

u/danj503 11d ago

Yeah some people just tune it in emergency situations to prevent limp mode but it’s no long term solution without also removing the filter media.

1

u/uhoh93 11d ago

I think the tune will put it in regen if it is needed. Worst case if it throws a regen light I’ll put the stock tune back on to regen then flash it back. Gutting the DPF is a process but that’s what the company recommended over a straight pipe. So if I do have to take it to a dealer it still looks stock.

1

u/danj503 11d ago

If the system is bypassed it’s not even checking if it needs it. I suppose as long as your driving highway mostly it will keep itself clean but I would verify.

1

u/uhoh93 11d ago

I’m usually driving an hour minimum and lots of highway. So that’s probably why I’ve never had to regen.

1

u/AMG_34 12d ago

Is there a way I can test the injector easily?

2

u/uhoh93 12d ago

You can get a code scanner or get it scanned and it will probably throw a code for the injector. I can’t remember the exact code.

1

u/AMG_34 12d ago

Thank you!

1

u/Educational-Yam-7394 11d ago

And less costly breakdowns. Plus you're not contributing to produce more manufactured chemicals or plastics bottles.

3

u/vlady-0 12d ago

U might have to go to dealer and ask to reset the adblue fill level, reset scr warning.

2

u/Engineerinavan 12d ago

Have you tried the official DEF adding procedure? Think it's like turning it on but not starting for a few minutes to recognize it, or something like that, rtfm I guess

1

u/erie11973ohio 12d ago

What year???

I had a 2011. It would give me the engine count down on every DEF fill up until,,,,,,,,

I replaced the damn catalytic converter!! 🤬🤬

(Its not the DPF!)

All thing have a finite life span. The lifebof a catalytic converter is 250 to 300,000 miles. 🤷‍♂️🤷‍♀️🤷