SCR System Efficiency Code
 

My X5D throw a code 4D16 SCR system efficiency.

I erased it a few days and about 100 miles gone by but it is back.

What could be the issue here?
It has about 112K miles and it's an 2010.
TIA.

Bad NOx sensors or urea dosing module. Just guesses but both are the subject of a 10 year or 120k miles extended warranty for certain diesel X5s. Worth getting it checked out but do your research and get a copy of the BMW NA letter first. Unless your dealer and service advisor are good and will put in the time to get this done for you. Left to their own devices they'll just charge you for the repair and parts.

Thanks for the response.
My dealer SA is very clueless, but I've got them to replaced my active tank for free about 6 months ago.

I will be bring it in to the same dealer and I will make sure the work is done with my consent.

Any update on this, as I am now dealing with the same issue. NOX Sensor and SCR Tank have been replaced. Dealer now saying SCR Catalyst needss replacement for $3500. BMW Canada says no warranty on SCR Catalyst. Any help would be appreciated.

The urea dosing module is also covered. That's what I insisted be changed when the dealership wanted to replace the SCR itself.

did you ever fix this???

Both NOx sensors replaced? Did they reset the NOx sensor adaption or just drop in new parts and send you on your way?

I haven't brought it to the dealer. I don't feel like arguing with them. I have been reset it once awhile.

The error seems to show up after a long highway runs. (2-3 hours on the highway). Then 5 minutes later on local traffic stop and go the code will show up.

I will keep reset it until the price of NOx sensor is below 200 bucks. :)

That's how mine behaved but stop and go traffic might do it also. Seemed warmer days made it more likely. Usually it would clear itself a few days later.