Rear parking sensors-intermittent fault

[XK8Dundee]

My rear sensors periodically just decide to give a constant beep when I select reverse, no rhyme or reason, rain or sunny, smooth or bumpy road . Car has been on. Jaguar diagnostic machine and nothing shows. Done the "ticking" test and all 4 sound the same so wondering best way to resolve. Don't have facilities etc to do myself so has to be a garage job. Typically the bolts at each corner are seized as I did try to loosen them. The guy at my local paint shop offered to remove/replace them as common issue on these cars and is prepared to remove bumper as well. I was thinking of getting 4 new sensors, getting him to spray match them and replace all 4 in one go (overkill I know but may be easier than removing bumper 3 or 4 times ). I assume the corner sensors are angled and centre ones straight but was wondering if something like the set on e-bay (hopefully link below works) would do the job as much cheaper than Jaguar originals.

Car is 2004 XJ6 (X350) 3.0 petrol.

http://www.ebay.co.uk/ulk/itm/331578426438

Cheers. Walter

[J44EAG]

Just got a 350R in the last couple of weeks myself with similar issues although the situation has improved with use. However...

With Barry and Paul hot on my tail about grounding points, my front sensor operation improved when I cleaned up the front earth tags. Remove the six plastic X head clips from the slam panel and set the clips and panel aside. Look to the rear of the outside headlights and on the vertical metal panels just to the rear, attached to the cross member you will find each side a 13mm black coated nut and two black coloured cables which are grounded to the panels. Remove the nuts, clean up any ring terminal corrosion, lightly smear with Vasaline NOT copper grease, then reassemble.

There are ground points similar to the fronts in the wheel well in the boot. One by the battery with also a long black extension cable on the OS. Similar exists on the NS. Clean up, smear Vasaline and reassemble. That might help.

Another issue is the connectors on the back of the sensors which corrode also. Often just pulling them off and putting back on again cures but as Paul told me, its really a bumper cover off job to get to the connectors.

Suggest you by genuine parts for the sensors. No need to buy new. Phone Eurojag who advertise in our magazine. Quote your Vin No which are the last alpha numeric figures seen in the black panel on the NS of the windscreen just below where the old tax disc used to be fixed. Vin No will be something like G33305. (My car)

Paint new sensors yourself with no more than three coats of thin paint from an aerosol and save money. Look on the NS A post in the door shut for a silver stick on manufacturers plate which will give you the paint code. Example MDZ which is Platinum Silver. Go to Halfords who for around £16 will make you up an aerosol spray can to exactly the right colour.

Mike K

[ptjs1]

Walter,

A couple of thoughts:

Are you sure it's the rear causing the problem? Is the sound coming from the rear speakers? It could be a front sensor causing the problem even if you're in reverse.

Do all the sensors tick when you actually have the problem?

Try unplugging and spray cleaning the p!ug on the PDC module.

Don't buy any parts until you know which sensor or other part is the problem. If they are ticking, they are working, is the basic principle.

Apparently you might be able to get to the rear corner sensor via the inside of the light cluster. Rob says you can, but I've not tried it!

Good luck

Paul

[XK8Dundee]

Hi Guys, thanks for swift responses, I only have rear parking sensors so can't be the front ones lol. Think I'll go first for having it all stripped out, cleaned and put back. Never know that may solve it, if not I'll be back for more advice.

Cheers

Walter

[ptjs1]

Walter,

As you know a strip-out means bumper off etc. Just try the plug connection first. It could save you a lot of time and money!

Good luck anyway.

Paul

[J44EAG]

The clean up is a very easy and quick job, Walter.

If you have an adjustable spanner, a small brass wire brush. some fine abrasive paper and some Vasaline, this can be very much a DIY job. About five minutes work for each connection unless the cable lug connectors need replacing.
This is the front off side connection point with the black nut that is removed to allow connections to be cleaned.

This is the same connection point with the nut removed. Slide the connectors off the stud. clean of corrosion and then reassemble with a little Vasaline. Repeat the procedure for other connection points on the car. Job then done.

Mike

[jeff1954]

I don't know if the 350 is the same, but on my 2004 SType there is a black plastic valance on the bottom edge of the rear bumper cover. This pulls off and you can reach the two inner sensors from underneath.

Jeff