and by "out" I mean they don't seem to be working at all.

01 XJR, about 183,000 miles on it. Car sat for a period when I had an oil cooler problem, finally got it sorted and have been daily driving it for about a month. Recently noticed that the backup sensors don't make a peep anymore, found it out the hard way by backing into a very large rock, no damage fortunately. At the same time, I've also noticed that the alarm no longer chirps when I arm or disarm it, door locks still lock and unlock as they should, but no sound. Wondering if these two things might be related, can't say for sure if they did or did not fail at the same time. Fuse, relay, some module buried lord knows under how many layers?

Thoughts?

Thanks!

 

The module for the parking sensors is in the boot fuse box and easily replaced as post 2000 the unit used was the same one they used on other Jaguar models. The beeper for them is mounted on the rear window pillar from memory.

The alarm chirp comes from a sounder mounted under the bonnet, it’s likely aged out or something.

 

The sounder is under the rear parcel shelf.

 

So last night backing out of my in-laws driveway which has a little culvert ditch that always has set off my backup alarm. Son of a gun, the backup alarm sounded when my back wheels went into the ditch, which points my bumper at the road surface. So maybe I'm looking at one or more failed or disconnected sensors.

 

My sounder is too low. My fix was to add a wifi camera that works with the Garmin nav.

 

Unlikely. If the control unit detects a failed or disconnected sensor you get a 5sec beep when putting the car in reverse, which is why I keep meaning to unplug the control unit in my car but never remember too as the 5 sec beep is annoying.