Hi and thanks for commenting. It's good to hear from the one who did it successfully
I did not know that the sensors could be connected in a wrong way. Is there something specific that could be done wrong when connecting them? Can the sensors be connected upside down, or in some way that the magnets don't function as they should?
The mechanic was completely puzzled by them not working and said it seemed straight forward to replace them. He checked the wiring and the sensors and all have voltage passing through them from the sensor to the panel, he said.
I did not see the sensors myself, as he ordered the ones you listed directly from his supplier (for a rather low cost of around 13 EUR each).
I will try disconnecting the panel, as you suggest and resetting the system.
He said some of the old sensors were corroded and some had their plastic housing cracked.
About the bypass, hopefully he will do that next week for me. I live in the Netherlands and the one VW camper dealer that has diagnostic equipment to hunt down what error 1000 means can't see me until the end of July