I know this is a crappy picture,,,,I don’t talk about BMW diesel enough,,,,so here we go,,,,this is a picture of a E70 left front lower bumper grill removed,,,,that is the SCR active tank,,,,customer came in with check engine light on,,,,fault was SCR temp senor incorrect ,,,,the SCR no temp sensor should be about the same as the ambient temp sensor,,,,that’s wasn’t the case here the SCR tank temp sensor was reading -4C while the ambient temp sensor was reading 26C,,,,big difference. You can not just replace temp sensor,,,,you have to replace the whole tank which comes with a new temp sensor,,,,You will have to removed the left front tire and wheel well liner to gain access to the SCR tank,,,,you can see the big metal bracket which holds it in place,,,,you first have to disconnect all the electrical connectors and hoses from the front bumper grill access opening and from the rear wheel well access ,,,,you will remove the tank and bracket both together.,,,,then you can swap over the bracket on to the new tank. Here’s the new tank,,,,now that white thing on top of the tank will have to be swapped over also,,,,that is the SCR pump which pumps the fluid from the tank into the exhaust system.,,,once you complete the replacement just fill up the tank with new diesel fluid,,,,good news no programming or calibration needed.,,,just old school change the part.