Troubles going bact to stock with a P249D

[rcr1978]

I'm having troubles with a P249D code after returning everything back to stock after changing emission tables, I'm not sure if it's related but this code is there right after clearing it even before a engine start. The only way I can get rid of it is turning the SCR system off. Anyone have a clue what causes this one, I guess H&S had troubles with this one to ?

[RADustin]

Is there a master reset to reset all the on-board controllers?

Maybe unhook the battery and let it sit for a while?

Maybe some other module has an SCR fault stuck in its memory so when you aren't suppressing the code it is showing up.

[rcr1978]

Tried the batteries already, only way of clearing codes on my end is what efi offers.

[RADustin]

is the injector dirty or line clogged from it being off?

P249D- Closed Loop Reductant Injection Control at Limit- Flow too Low.


That's all I can find on mitchell. Might need a tech2 to reset maybe? Is it throwing a poor quality message in the dash?

[rcr1978]

Well that's what I thought, took the injector out, hooked water to it, pressurized it and pulsed it on with a battery and it seems to work fine. I have got the quality message but it has since gone away on it's own, It's weird I can clear the code and then start the engine and within a second it's right back even before the urea pump even tries to build pressure.

[RADustin]

could the line or tank be clogged? that shit crystallizes into a rock...

[rcr1978]

No it all works, I unplugged the line from the injector and went for a drive watched the pump come on in the scan tool and the thing pissed all over under the truck. I've been noticing my NOX sensor #2 seems a little lazy it drifts around and goes over a 1000 then negative sometimes plus I heard they a pretty common to be junk so I'm going to try one off my buddies new truck before I buy one, they are expensive as hell just to try out without knowing for sure $370, probably could be found cheaper but that was dealer pricing.

[RADustin]

I had one on mine screw up. And I had a harness issue.

I don't see the NOx sensor as a possible problem to cause P249D though.

[rcr1978]

Well after a couple of weeks fighting this P249D it has now been gone for 3-4 days and everything seems to be back to normal, I have had the EGR and urea off for quite some time with the stock exhaust in place and I'm thinking the SCR just took a while to clean the NOX out of it or something or I have maybe even hurt it a little but it acts normal now. I guess it's probably not a good idea to run without the diesel exhaust fluid system functional while keeping the dpf/scr in place.

[Mitco39]

I have this same issue on a returned to stock truck. Did you just let it work itself out and the code finally cleared itself? Its not a huge deal for myself because the customer is removing his exhaust this week and it was flashed back to stock just so he could drive it in the mean time. Its an annoyance tho.

[rcr1978]

It took a long time to go away like 1000+ miles if I'm remembering, there was never a limp mode associated with the particular code but other problems would come up like def quality ect... I would just clear it every time I drove the truck and the check engine light would stay off until the next key cycle. And one day it was gone for good and has been since probably logged another 1000 miles afterwards stock with no problems.

[Mitco39]

Weird, I guess thats something to be aware of when doing deletes. This was the first truck I flashed back to stock and it was the first time I saw this issue. I hope its not an overly common one. Thanks for the info!

[Mitco39]

One weird thing I cam across.

So I flash this 14 LML with a deleted tune (still has that damn error message, but thats another story). His wife is driving it home to him so to be on the safe side I load up the 100% stock tune and flash it in just so that there are no issues. He gets the exhaust cut off while he is at work and then drives it around 1.5-2 hours with no limp mode (but def speed limited message that never happens). I know for a fact that a deleted truck with no tune will limp virtually instantly, so it seems to me like the stock tune does not fully recover the ECM from the deleted flash. Dunno if this is the case, just what I experienced last night.

[rcr1978]

I was wondering if all the modules just are not getting reset, I don't have a Tech 2 or any other scan tool to try and clear everything with.

[Mitco39]

hard to say for sure, Im not even sure what the tech 2 would be able to tell you. I plan on getting one of them in the near future.