I was having some trouble with my reversing sensors in that they seemed to decide when they were going to work and when they weren't.

I told the dealer, who said there was a replacement ECU available. I think that they replaced it.

It's still a bit finicky but I've worked it out. The sensors activate but not until the park brake is released. Furthermore, it must be released manually. If you start reversing and let the park brake automatically disengage, the sensors don't activate.

Just thought I let any affected owners benefit from this minor experience of mine. Otherwsie they might reverse to close to the garage door and leave a dent in it......not that this has necessarily happened to me... or that I'd admit it anyway...