[cm335d]

Hey folks, I need some diagnostic help. I'm currently getting the 4BCD code related to the DEF system 'Reducing-agent passive-tank fill-level sensor plausibility'. I've read some references that mention the 'processing unit' part number 16197227394' is the culprit when this happens. The DEF tank was replaced under BMW's extended warranty about a year ago. This code isn't new, I've been chasing some others and finally got down to just his one left.
Anyhow, can anyone confirm that this 'processing unit' could be the problem? I searched the forum for a location of the part and the best I can tell is that it is here: https://photos.app.goo.gl/rRiutX1agE8Zwmzz6
Thanks very much for your help!

[cm335d]

I think I've found the location of the processing unit, but would like to know if anyone knows that this 'processing unit' can set the 4BCD code? I'm planning to order this from FCP Euro shortly.

[cm335d]

Allright folks, I am happy to report that I've found the problem causing my 4BCD code. It was, in fact, the dealer's fault when they replaced the DEF tank under extended warranty. They swapped the plugs on two of the tank connection points.
https://photos.app.goo.gl/7SeL66DmH3c4khNH6
https://photos.app.goo.gl/FFHgusxZWMj7FYjf8

My SES light is finally not illuminated! Yay!

[DougNBodie]

Thanks for the info....Got the same code