Hello together. Since I found my problem in other forums, but still I don’t work with my Doblo, I’m addressing you. I have a rigid Ahk (brand Auto Hak) with specific 13pin cable set (brand Jaeger), so matching plugs, check control and PDC shut-down attached to my Doblo on the weekend. Everything is tested and works as it should. However, if I plug off the trailer, the PDC reports a permanent tone, although behind the Aut o nothing is located. (The trailer is pushed away and the car is horizontally on the asphalt) The fault here is the hook of the coupling. If it is disassembled, the PDC works as it should, the hook is attached to the permanent tone. I tested the sensors for function (tick if I keep my finger on it) I tried to adjust the sensors (doesn’t go there plastic with snap function) I checked all plugs and cable connections again, also those of the PDC since I have the S The pen in the connection box, which is responsible for the rear fog lamp and the PDC, has not been suspended either. I called my Fiat workshop and the problem is unknown. According to this workshop, the PDC is not reprogrammable or similar. Even the manufacturer of the Ahk is not aware of this. If I hold the two internal sensors with my finger, the continuous tone is gone, but the other sensors then also work. no more. I don’t know any more advice. Do you have any idea what else I could do? Thanks LG