Park Brake

[J44EAG]

I believe that an ABS unit on a wheel bearing unit or a sensor on the ABS unit itself can cause some issues similar to those you describe.

The wheel ABS units connect to the unit via a short link cable fitted with a plug and socket. I was about to photograph one I have here, but it has wandered off somewhere. as soon as I can find it, I`ll post a pic. It is perhaps worth separating each wheel sensor plug and socket arrangements. Just a little corrosion could be the problem and a quick clean up might with luck clear the issue.

If that doesn`t work, then you may need to have the car scanned.

Mike

[clivelewis]

Thanks again fir your advice Mike - dicky sensors sound about right in the circumstances - when I have a few minutes after the pressures of another Six Nations weekend I will have a poke around and see where it gets me. In trouble probably!! Heigh Ho. Best regards.

[jeff1954]

Hi All.
MOT passed today (Thankfully) allthough I didn't get chance to ask the tester how he tested the parkbake ie without the rear wheels moving (re my previous post) Never mind, all is well now for another 12 months.

Jeff.

[J44EAG]

Found a pic of the sensor lead. Still can`t find the lead itself which has gone walk about!

Mike

Right, found it. The lead has two bright metal male prong connectors in the large round plug end. . The lead would appear to have a light two wire central core but the other end of the lead is perhaps best described as a hall effect type sensor which plugs into the ABS/wheel bearing cartridge . The lead is exactly one metre in length with four long rubber grommets used to secure the lead to suspension and body components.

The lead is marked FOVB-14A459 on the round plug end and 1404 on the cable. Sorry, no Jag reference number at this time.

[clivelewis]

Hi Mike and all....I mentioned a while ago that I had a reoccurrence of warning lights 'ABS Fault" and 'DSC not working", albeit intermittently. Well intermittent became every time the car went over thirty miles per hour! The lights would reset after ignition was turned off but came back on again every time we got rolling. I am sure those of you with a modicum of Jaguar engineering knowledge (which does not include me) will have guessed the problem by now. I took the car to an independent Jag specialist at Newton Abbot (they advertise in the club mag) and the diagnostics indicated that a drive shaft sensor had failed. Physical examination revealed that use of the car had resulted in damage requiring replacement of the drive shaft and sensor. As the old girl is due a service anyway, we are booked in next Monday for the remedial works, full service and gearbox oill change. Have already surrendered passport to bank in anticipation of their future reqirements. I'll let you lnow how we get on. it is quite difficult to find independent Jag specialists in this neck of the woods so it may be of interest to other members on how things go for us. So far, I have to say, so good. Watch this space.

[J44EAG]

You might be able to ease the financial pain by contacting Neville Anderson at North East Jag Spares or Eurojag and try to obtain a second hand shaft and bearing/sensor unit.

Prices are generally around one third of new and there are loads of quality used parts out there often with a half decent warranty.

Well worth a couple of phone calls to save a few quid.

Mike

[clivelewis]

Thanks Mike, Garage have already offered parts at 50% discount from normal which I thought was pretty good. I am keeping a list of the suppliers you have suggested to me for future use - I'm sure I will be needing them !! Hope to meet up at one of the events this year?
Best wishes, Clive.

[J44EAG]

Hello Clive,

I shall be at Weston Park on the forums stand. Perhaps we can hook up then?

Mike

[clivelewis]

Hi Mike and all.......At last an update on the warning light sagas......The ABS Fault and DSC not available warning lights were finally pinned down to a faulty ABS speed sensor on one of the rear wheels. This was found and confirmed thanks to an independent Jaguar Garage with the right equipment as I outlined earlier. Unfortunately, and here is a word of advice to those who suffer anyintermittent fault lights , the continued use of the car with the faulty sensor caused damage to one of the drive shafts. This had to be replaced (over 400 quids at retail I understand - although this garage fitted a second hand unit for 170). This does sort of reinforce the message that if a fault light continues to illuminate - albeit intermittently - it is worth getting the fault scanned to prevent any additional damage being caused unknowingly. Coupled with an 80,000 service, two new rear discs and pads, I have had to hide the bill from SWMBO again!! Apparently the rear flxible brake pipes are also showing some signs of rust and will need attending to probably before MOT time next Jan. AND the air con is not functioning after having leaked out all its wassisname. (during the winter I had not really noticed this as the heater side is working). So have to arrange for a regas to find out where the leak is (probably near the pump) and see what the prospective damage will be. I hope there will be enough wheels left on the wagon to make to Weston Park!! Therefore hope to see you there..........
Regards, Clive.

[J44EAG]

Pretty normal then!

I`ve a bust window regulator, no air con and the drivers door won`t unlock when you switch off, the air bag light is on, the fag lighter has lost its ground connection and I`m still rolling along!!

Mike

[jeff1954]

Have I missed something here, how can a faulty sensor cause damage to a drive shaft.

Jeff.

[J44EAG]

I missed that completely.

I agree. We have two units that tie together mechanically, but a sensor just senses rotational velocity and has no physical link with the mechanical aspect of the drive train. I can`t see the logic that a failed sensor would cause a new drive shaft to be fitted.

Mike

[clivelewis]

Hi Mike and all, Sorry- if you've seen any of my previous ramblings you will know that I have the in depth mechanical knoweledge of a duck billed platypus. That does not alter the fact that I love the car to bits and I certainly do wield a mean chamois and polishimg cloth. Concerning the drive shaft etc - I have only served to pass on my own confusion with added value. It may well be the other way round - the drive shaft running without oil and bu***r**g up the sensor? I distinctly remember the words running in oil, so when it fails it also affects......... Suffice to say that the old girl is now running well again, no warning lights (touch wood) no transmission judder under cornering/acceleration etc. The point I was trying to make (evidently badly) was that it may pay to have intermittent warning lights checked sooner rather than later, and not to assume the cause is an electronic glitch because of the inconsisterncy. Will try harder.

[J44EAG]

Thanks for the update, Clive.

The part you describe running "in oil" would only be the short output differential stub shafts which terminates in a drive flange, one on either side of the car. Oil is retained in the diff by an oil seals. Drive from the diff goes to the two rear wheels via shafts about two and a half feet long. They both terminate in a constant velocity joint unit which has the reluctor or sensor ring built onto the outside of the joint casing and a further stub shaft upon which the hub to which a rear wheel is bolted. Sometimes the reluctors break and a new or secondhand joint is required to get things going again.

The joints are located inboard of a vertical hub carrier unit which also houses a large rear wheel bearing unit on both sides of the car. The rear wheels are nutted to a drive flange which is nutted in turn to the stub shaft on the joint unit.

The CVJ (Constant velocity joint) units are usually packed with grease only and require no attention during their service life. They do not run in oil so I`m a tad confused as to just what work has occurred on your car.

Mike

[clivelewis]

Wow. Great swahili Mike - (I did warn you !!) I'll speak to the garage again and try to take a bit more detailed notice !! Hopefully, if you can bear it, I'll try and make things more understandable to someone who knows what they are talking about !! Clive.