Hello Guys,


I have been reading your comments and I consider myself lucky to be admitted into this exclusive club. Thanks for your help in advance. The car is a new acquisition so I don't know much about its history, but I do know that she was well equipped from the factory. Here is the issue I am having with this 2003 Jaguar XKR:

The message "cruise control not available" shows up on the dash. The car is equipped with an adaptive cruise control unit (audible chime switch on the left side of the steering wheel on the dash and the "+" and "-" signs on the right side of the steering wheel). My friendly local parts dealer quoted me around $2000 for the part - there are 4 different part numbers for '97-'06 models. BBA remanufacturing (who successfully repaired my ABS module) also quoted me around $1500 to "try" to repair the adaptive cruise control module.

Has anyone here been able to repair one of these modules? I know you can easily fix the seat control module by soldering a wire to reconnect 2 parts of a circuit interrupted by the board being tightly wrapped in its plastic box. Is there a similar fix for the speed control module? At the moment I am held back by the fact that I understand it sits behind the front bumper so the front bumper has to come off to get to it.


Please let me know if you can help,

Valentin Cristea

 

I have no idea if you can repair it, but I do know that if you place in a new one you should also again re-calibrate the system to do it right, and that according to my local Jaguar dealer could cost a couple of hours as well, so that needs to be added to the costs.

So if you can’t repair it, then the only way to get rid of it is a painful one. This is something your dealer could do, but it requires to get a new vid block from Jaguar (iirc 50 gbp), which you need to use to re-program about 5 modules iirc in your car (ECU, TCM, Instrument Cluster, Stability control and probably Body processing unit). You also have to do this in a specific order otherwise there will still be a unit complaining it misses the ACC. That’s all I know about, it requires some patience and WDS/IDS skills to do so, and there are not many dealers who want to, or know how to do this.

 

Not tackled this one myself but if you really want to give it a go, then you will need either a real IDS/WDS system (dealer scan tool) or one of the Chinese knock offs.

That will let you read the actual codes from the ACC system and also do it's calibration once you have it fixed.

It's hard to say what might be wrong with it without having any of the error codes, and unfortunately the display on the dash tells little more than "it doesn't work!".

The knock off dealer scan tools can be had pretty cheaply and there is a very thorough and often visited thread about them:
https://www.jaguarforums.com/forum/g...-66558/page22/

 

I always try to fix any and all issues I find in a car. However, this one looks to be untouchable to me. I was hoping it would be something I could fix. It looks like even if I hit the lottery and do manage to save some € by fixing it myself, there is no way I could re-calibrate it. I am pretty sure the local dealership SAs are not even trained to do that, but I can ask them today just to confirm. Speaking of patience, it requires that on my part too, when they charge me $110/hr of labor :-) A few hours of labor with no results to show would be a quick way for me to throw in the towel :-(

Now I can see why this option was so rare on these Jaguar XK8/XKR cars...

Thank you for taking the time to respond.

Valentin Cristea

 

Thank you for your help Charlie. I think my mechanic scanned it with a SNAP-ON tool. I will ask him today what error code was put out by the scanner.

Sincerely,

Valentin Cristea

 

With the bonnet up there is a metal box on the passenger side, that is the ACC module.

It is somewhat awkward to get to but the bumper doesn't have to come off. Putting the bonnet in the service position should help though.

It's basically a radar and the calibration is mainly to set the right-left sweep so that it doesn't pick up road signs and the like. If you managed to get it working the error message should go away, even without the calibration.

The module sits out in all the weather, so you might inspect the harness running to it and clean the connectors just to see. It never hurts to clean things, and it's free.

There are wiring diagrams linked in the sticky, which are handy to have.

Codes will point you more in the right direction, but you can at least cover the basics like whether the +V and ground are good.

 

The BBA reman in the UK quoted me Ł600 to repair, but I managed to buy a used one off eBay and it just plugged in and worked, all the lights, messages disappeared, I also opened up the faulty one, looks like something out of NASA, by the way, it took me 18months to find the used one, good luck.

 

Just a thought - is it definitely the ACC module that is faulty?

I've frequently read that a dud brake switch can cause this fault with normal cruise, and since (according to JTIS) an ACC system is similarly fed with a cancel signal from the brake switch combo it could be a fault there that is triggering the error.

It's possible to check the switch with a multimeter, and it's a much cheaper item than the ACC module. You can do a home repair if you're handy with a soldering iron as the switches themselves are standard pcb mounting microswitches. Dead easy to remove from the car but a real pain to refit..

Mike

 

I had the same issue with my 2005 XKR "cruise not available" & no Fwd Alert when i first bought the car. The issue always came about after the car had been sat all night, but was OK after a 20 mile drive....the fix....New battery !! I've had the car 3yrs now
and it's never returned.

 

Interesting - and even easier to check. Out of curiosity, did the windows lose their memory at the same time? Or perhaps the ACC is even more sensitive to voltage drop.

Mike

 

When my brake switch gave out it also came with a "Check Rear Lights" message in addition to the cruise not available.

Don't suppose you also are getting that message?


Also a very good point, questionable batteries cause all manner of strange behavior in these cars.

 

I was having the classic problems with this message and shift sticking in park until I R&Red the switch. After the dealer changed a tail bulb at the last service it's now on permanent display. I also have a fine collection of spare bulbs that didn't resolve the problem

My car doesn't have cruise, but I understand the two switches work in tandem and if one fails, the ECM can't rationalise the signals so throws the "Cruise not available" message, among others..

 

No.....just the ACC was an issue. The strange thing was I would start the car 1st thing in the morning & the message "cruise not available" would be displayed if I tried to engage cruise, also the RED FWD alert LED would not light up.
After driving 2 or 3 miles I could turn off the ignition, restart the engine and all would be as normal, cruise worked OK. The same issue would return if the car was sat for some period of time.
My guess is the battery was "on the edge" & starting that V8 would take any guts it had left in it. TS

 

Thanks for the picture you provided Charlie. It sure makes it easier now to identify where it is. I will check it out as soon as I get the car back from the painter - it's got some dents and scratches I have to get resolved first.

 

Thank you for the picture you provided Charlie. That makes it a lot easier for me to identify it. I will check out all the connections to it as soon as I get the car back from the painter - I have some scratches and dents I need to repair...

 

I have replaced this brake switch once before on another XK8. It wasn't fun since it was hard to insert it in such a way as to fit in its intended holes. I gave up in the end but luckily my son made it happen
I don't remember why I had to replace it, but I know for sure the car didn't have adaptive cruise control. I think I was probably getting the message "Check Rear Lights" and the Jaguar SAs correctly informed that replacing the brake light switch would fix the problem. I know for sure that on this XKR, I am not getting the "Check Rear Lights" message at all.

 

A drained battery would be such an easy fix! I will connect the slow trickle charger to the battery as soon as I get the car back from the painter. I know the car sat for a while and at one point had to be jumped since it was "dead". When I picked it up from the mechanic it started out just fine though...

 

Do you suppose I should replace the brake switch even if I don't get the message "Check Rear Lights"?

 

The battery can be deceiving. I had an experience last year where I was getting Airbag Faults and other occasional odd behavior, but the car started and ran fine every time.

The telltale was when a Trans Fault started flashing briefly when cranking the car over (voltage droop).

I changed the battery an all of the problems magically went away. And the starter spins noticeably faster now too.

 

Bear in mind that your brake switch is two switches in one, so different errors may be thrown depending on which one is faulty.

I'd certainly go with smithtrevor's suggestion first, particularly if the car has stood for any length of time with the battery discharged.

As Charlie rightly says, weird stuff happens to our cars when the battery goes on the fritz. In my case, the only symptom was memory loss on the windows - the car started on the button and ran perfectly. Replace battery = no more window problems.