For several years, I had unreliable front parking sensors. They beeped randomly at slow (parking) speeds and were particularly annoying in the wet. I tried all the simpler diagnostics/fixes in the forum, even removing the front bumper to check the wiring for corrosion. After a couple of years, the “parking sensor off” switch broke (from over-use) and I had to dismantle my overhead console to fix that!

I eventually asked an Auto Electrician if he might be able to sort out the problem, and he asked “do you have chromed number plate surrounds?”. Um... Yes...

The car is a Japanese used import and was supplied with a front plate plinth that’s narrower than NZ number plates. The front parking sensors are “upset” by the reflections they “see” from the sides/edges of the front plate (particularly if it’s fitted with a chromed surround).

Solution 1: Not wanting a “naked” front plate, I glued rubber strips to the sides of the plate surround: problem 90% solved.

Final Solution: I bought a wider, number plate plinth on Ebay and fitted this to the front of the car (an original Jaguar part, but I’m not sure which market it was originally supplied for). It’s a bit wider than the NZ plates but looks better than the original (slightly too narrow) item, particularly since I could get rid of the rubber strips. The best part is that the front sensors now work 100% as expected, they were ok all along!

 

Glad you found the problem - also to keep in mind, since you have front park aid, I have seen issues where the license plate bracket is too far to one side, setting off park aid. If for some reason in near future you need to replace it, keep that in mind.

 

Any chance of a photo David? My front sensors go off occasionally so I'm interested in your fix.

 

As requested:
The first photo shows the old, narrow, Japanese market plinth.
The second photo shows the new one fitted to the car.

The new plinth shields the plate itself from the parking sensors. The rough plastic surface of the plinth obviously damps or disperses the sensor signals enough not to register.

P.s. Yes, I know the plate looks a bit scruffy, but I’ve had in on four different cars over nearly 20 years.

 

Ideal. Thanks and will keep an eye out for one.