Hyundai Tucson Oil level warning no longer goes out

Hello, I currently have a problem with the Hyundai Tucson 2.0 crdi 4wd Diesel Automatik The car started with the oil level warning lamp, oil replenished and I thought well. Push cake, the lamp remained on. I rolled the BA the next day and then found the point where the manual reset is described, unfortunately the was unsuccessful, even after the described 50-100km no change. We then preferred the next service a bit and the car among other things to change oil into the (free )Workshop where he has been standing for a week now because they can’t get out of the lamp either. Oil level sensor was of course immediately changed but unsuccessful. Now yesterday the workshop master called me to explain that the fault is produced by the LIMA and he wants to exchange it now for a good 700€…. I have forbidden him the exchange now and decided for me that I prefer to look for oil more often and then the lamp stops because it only remains a Note is, if it gets arg goes on anyway the oil pressure warning lamp. Besides, I don’t believe that that’s really right on request if he tried the manual reset he answered not satisfactory and 50-100km he certainly hasn’t driven with the new sensor yet, so I have the feeling the lamp will soon start on its own. Is here perhaps someone who can explain to me how the alternator can produce a fault over the LIN bus which then ensures that the oil level ensor plays crazy?????