Front parking sensors

[GeoffH]

The front parking sensors have stopped working - I just get the warning triangle every time I start the car. It's been to the dealers but they cannot find a fault using their diagnostics tool nor by visibly checking the wiring and fuses. They are now proposing taking off the front bumper - needless to say this is at vast expense. Anyone had anything similar?

[crockers]

Does the car not have a warranty? If not I’d go to an auto electrician.