I have a 2011 XJ Supercharged and I'm getting the "Parking Aid Not Available" and long beep when I drop into reverse. Strange thing is, it normally works fine in the rain. One of my sensors seems to be loose in its housing. Can anyone explain how to get to these rear parking sensors?

Crawshaws, unfortunately, you need to remove the rear bumper cover to access the sensors. Not that hard. Just takes a little bit of time (about 30 minutes to get off, 30 to get on). Then the sensors just snap into place and have a single electrical connector to the sensor. You should be able to get an idea of which sensor it is by putting your ear next to the sensors and you should hear a high pitch chirp/squeak. The one that is not doing it, that is your bad sensor.

I had a sensor go bad in the front and when parking the front sensor display would come up and it would display the front sensors, but the bad sensor area was not illuminated. Hope I explained it well enough. Now I have a 2013 and am not sure that the major update to the electronics would make a difference.

Thank you Thermo - that's what I needed to know. I don't mind removing the bumper, I just just didn't want to do so only to find out I should have gone in from the inside, hahaha. Thank you for the guidance!

Thank you XJsss - I'm getting no specific sensor indication on the display - just a "Parking Aid Failure" warning. It is an intermittent fault and it often works if I wet my rear sensor #2! That sensor also seems to be loose in it's socket. Anyway, I'll be going to remove the bumper to take a look and replace sensor(s) over the next couple of weeks. Thanks for the reply!