Mk1 Technical : Parking sensors not working

I checked all the sensors and even brushed them with a toothbrush to remove any dirt. Still had a a continuous beep. No error messages on the ODB port.

In my case, the control module also *looked* dry But you can carefully open it once unplugged. There is 4 tabs you need to push in and pull at the same time which is fiddly. I used matchsticks in each slot to open it wide enough to pull to check.

What I found is that condensation had got in and looking carefully at the inside the plastic box where it slides in I could see some green corrosion from the PCB board even through the PCB looked fine. Strangely a spray of WD40 across it and it worked for again for 5 minutes But at least proved it was the problem.

I found a low mileage replacement part and swapped it out and it works fine.

I am not entirely sure But to be on the safe side, you can see the software and hardware version printed on the module so you should get one thats identical since its married to the computer.

If I get a chance I might run some silicon around the box edges to seal it properly.

Overall, it seems these boxes are very sensitive to moisture and its just time until you get condensation in it. I didn't even bother asking a Ford dealer for a price since even the used prices started at a 100 GBP given these are in high demand.