[capt_slow]

Was filling up my DEF a while ago and usually do this with ISTA open. Back then, I noticed the passive tank progress bar was erratically jumping from 0 to actual level. Didnt think much of it.

What I'm seeing now using ISTA ECU diagnosis is the passive tank is reading 0% one day and actual/full other times. I think the level and temp sensors are integrated into one unit on the tank, and temp reads normal. I visually inspected the sensor from the outside and it looks fine, no damage nor signs of DEF leaks. No codes either and active tank is fine. Could I be looking at a new tank in my future?