No know problems. Think of these def tank level sensors like a fuel level sender. They operate almost identical to each other. What does the dash gauge read compared to the level of the tank? Is the new sender open or shorted? Seen it happen. What's the DTC its setting.
Just to be sure there is no confusion, it is the ad-blue tank that is setting the dtc and the car won't start when the tank is empty. It is a colleague of mine that asked me about this one. I will get the code tomorrow and any extra info.
Ok. To clear up this mess;) I talked to the Tech today.
The car does start, shows 46 km left of ad-blue. No Level indicator in cluster exept the Km till you have to fill. After that the car goes into limp mode.
When the car came in it had a fault code for the nox sensor after the nox trap. This went away when they reprogrammed the PCM.
So now there is no dtc, but the car fails to run the self test of the ad-blue\nox system on startup.
The level sensor is a 5 wire sensor with no moving parts. Probably a segment sensor with different levels of shorting points.
We have very little info on this system, and running a little lost on where to start.