F10 520d (2014, N47) – SCR / AdBlue issue, stuck countdown at 50 km

[ovidiumuntean2006]

Hello everyone,

I’m having an issue with the SCR/AdBlue system on my 2014 BMW F10 520d (N47, xDrive).
Symptoms:

• On the dashboard (KOMBI) it shows: “Refill AdBlue in 50 km” → this warning is frozen, it never decreases.
  
• On the iDrive/head unit, it shows: AdBlue level ~17L and range ~700 km (which decreases normally as I drive).
  
• I’ve already driven ~110 km since the warning appeared, but the dashboard still shows 50 km fixed.
  

ISTA results / error codes:

• 29FB00 – SCR system, warning and shutdown scenario: Warning level 1
  
• 29FC00 – SCR system, warning and shutdown scenario: Warning stage 2
  
• 805256 – Active tank SCR fluid level sensor: Echo recognised as faulty
  

What I did so far:

• Emptied and cleaned the AdBlue tank, refilled with 14L fresh BMW AdBlue.
  
• Replaced the tank cap (the old one had a broken seal).
  
• Ran ISTA 4.39.20:
  • Cleared DDE & SCR fault memory multiple times.
    
  • Tried Reset adaptations and SCR adjustments/adaptations (active tank + “AdBlue replaced” reset).
    
  • Attempted Initialization of SCR tank system several times → procedure always aborts (doesn’t complete filling/draining/pressure build-up).
    
• After resets and sleep cycles, faults 29FB00/29FC00 always come back.
  

The problem:

• Dashboard warning is frozen at 50 km (not counting down, even after driving more than 100 km).
  
• iDrive shows AdBlue range correctly and decreasing.
  
• Initialization in ISTA always fails.
  

Question:

• Has anyone seen this mismatch before (frozen KOMBI countdown, but iDrive range working)?
  
• Is this definitely pointing to a failing active AdBlue tank module (pump/level/quality sensor unit), or is there another reset procedure (e.g. Tool32 job, E-Sys) that could clear the 29FB00/29FC00 shutdown stages?
  

Any advice or experience would be greatly appreciated.

Thanks in advance!

[ek1978]

No easy fix for such problems , you need new Adblue Tank which has the pump and the level sensor inside , expensive fix unfortunately .

in order to avoid such problems in the future , always use some Anti-Crystal Additive like LIQUI MOLY SCR 21898 for example.

[Dafoff]

805256 – Active tank SCR fluid level sensor: Echo recognised as faulty

Come ONLY with tank adblue
Amazing price)))

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in order to avoid such problems in the future , always use some Anti-Crystal Additive like LIQUI MOLY SCR 21898 for example.

No
Every +/- 2-3 years, depend motorhours , need New tank
This sensor very bad QUALITY and BMW know this
It is ultrasonic. It calculates the level by the liquid surface mirror

That's why I use Mercedes V12 bitubo)))

BMW, my first car which I bought at 18,
20 years ago
I bought this car from a gypsy baron in Moldova (plate number SR - Soroca (city), BN = baron

Evacuator - every month, this is normal
And in 2005 year, with car Parts for 740 you can have very big brainstorm. Neded wait 1 week and price not 1000 eur.... 2-3-4
But this car had a big plus. Number plates . Not a single policeman or bandit touched me







The last straw was a 2 year old F07, 7 years ago. Where I also changed this AdBlue tank. And if my memory serves me right, the 3.0D has 2 of them.

And now I've been driving a Mercedes for 7 years and I don't have a headache