[bmw335d]

Hey Guys,

Need some help.

So here is the situation. Yesterday I got the def warning light which I get every so often indicating to refill the def.

I got the warning No start in 1600kms, which is what I normally get.

So I filled up the def with some fluid I had left over from summer, and I noticed it only filled a bit, about 3 liters or so, normally its 5-6 liters.

Anyhow after that I drove a bit and the warning went away.

Then today after about 80kms of driving I get a No start in 300kms in red this time!

Why did it jump down so many kms, after scanning with ISTA/D I get the error:

SCR System: System error and poor urea / water mixture quality detected.

So could this be cuz of the old def I used from June? Does Def go bad? What should I do, I got no warranty and now it says only 300kms left.

Could it be crystallization in the line? Should I drain the current def and refill first.

Appreciate suggestions!

Thanks

[floydarogers]

Read this thread (another forum). There are also threads here IIRC, but the link is much more compact.

http://www.bimmerfest.com/forums/sho...d.php?t=984485

[Yozh]

Urea has 6 months shelf life. Increased temperature makes it worse. 200mi/300km warning is a bad Urea warning. System detects it whether you pee or put water in your tanks. Drain tanks, flush with distilled water. Refill with fresh urea. Check date of manufacture before you buy. At the same time, clean your urea nozzle. Easy and practical.

[bmw335d]

After I clean the nozzle and replace the fluid, I need to reset something with ISTA software then run the car.

Do I need an ICOM to do the reset or can I just do it with regular d-Kcan cable + ista?

These are the errors I am getting in ISTA:

41F9 - SCR System: System error and poor urea/water mixture quality detected
4748 - SCR System, warning and deactivation scenario: Warning Stage 2
474C - SCR System, warning and deactivation scenario: Warning Level 1


Also I got 4D16 intermittently over the last couple weeks but it never threw a check engine light, it was just stored.

[alex sol]

i had similar issues and instead of replacing nox sensors and cleaning the nozzles, i made a bee line to jr in oakville and tuned out all the emissions problems... after 5 months, no issues. except... i am only making 12 psi boost so will look into this problem.. suspect dirty dpf or clogged scr and maybe vacuum leak

[bmw335d]

I ended up getting the tune, feeling better now

[cubismy]

similar issue !!!! HELP!!! Can you tell me how to fix it ? @bmw335d & @alex . thank you so much !!!!

[Yozh]

Several things to try. Flush your tanks. Full with good fresh urea. Make sure your urea metering valve/spray nozzle is not clogged. Make sure your motor runs at proper temperature 86-88C. Failed thermostats and motor running cold will throw SCR efficiency for a loop. After all of this, you may be looking at new/used NOx sensors.

[bmw335d]

I too ended up going to JR to get a tune. For my issue it looked like it was one or both of the n0x sensors and it was cheaper to get a tune, i did an EGR / SCR delete with a JR tune, no regrets, and no more need to fill urea.