So my Adaptive Cruise Module is faulty and is interfering with the Can Systems for my 2004 XJR. This has been diagnosed by my Main Dealer and an Indi, both say the same $5100 plus fitting for a new one $2500 for a rebuild if they can get it done or you could try a second hand unit that may or may not work but they are so rare you probably won't find one.Both say they do not know if there is a way to bypass the system so that I don't have Cruise but car will drive without the risk of limp home or Restricted Performance. Can't believe that one box that I never use can turn my car into a possible parts car! Does anyone have any ideas don't think I can justify spending nearly $6000 for a car I paid $12000 for. Other than this fault my car is mechanically sound and looks stunning. Really quite annoyed at the moment.

 

Could a hard reset cause a problem with the ACC as this started when I disconnected the battery?

 

The ACC can be bypassed, I looked into it as a retrofit for my XJR, need to get at my laptop, tomorrow. If you can wait?

Another option is the dealer tries to reflash the ACC module.

 

Robert,

It looks like I may be in the same boat that you are. I bought a 2004 XJR 3 weeks ago. Everything (cruise, distance warning system, etc.) worked fine until I took it home. The next day an amber light and "Cruise Not Available" message showed up on my dash. I have not taken it to the dealer yet for diagnosis, but am fearing the worst. If this pristine, low mileage Jag requires any repair that you wrote about, I just lost my butt on this car purchase. The former owner told me that he recently had to replace the battery due to low voltage. I tried a "hard reset", but it only seemed to reset my trip computer. Do you or anyone else have any ideas before I pay at least $120 for Jaguar's verdict?

 

Hi Cambo, of course I can wait I am not going anywhere, if you can work out how to take the ACC out of the loop you will of answered my prayers. Can't believe that one box that I never use can cause all this crap. XJR trooper watch this space and I am sorry that you are having problems, I would still get your car checked as apparently there are lots of causes of a ACC can fault I was hoping mine would be a switch or bulb or fuse but no mine was confirmed as a failing unit. Apparently this is not a new issue but I did not flag it before purchasing my car, now I know.

 

Robert,

I will continue to monitor this post. I know that without a proper diagnosis, my post may have been premature. I like to review all available information before taking a step. I was hoping that I could do something simple and the light would go away. Thank you everyone in advance!

 

Anyone know the correct unit part number as I read threads it seems that the unit numbers are a 2W93 number but my dealer says the unit part is C2C23960. Another member has found a part which is supposed to fit my 2004 XJR ending vin G33676 the part number is 2W93-9AA12-BE for Jaguar XJ G26026 thro G34526. There seems to be some confusion on numbers can anyone clarify.

 

You can disable the ACC using the SDD/Mongoose

Set it to ACC "Not Fitted". This will bypass the ACC module
Scans will still find it tough so you may need to take the plug out of the module and radar

This will take you back to STD cruise control

Cheers
34by151

 

Thanks 34by151 believe it or not I think I found a brand new unit ACC for sale in the UK for $700 and my relatives there are trying to buy it for me. If this does not work I will try that fix. I am sure that you are right the main dealers says my car will still not work, but I was told that it may be policy that they do not do it so would see if my indi with an auto logic could do it.

 

C2C23960 is the part number on Jaguar's price list. The code starting 2W93 is what will actually be on the unit so they are both right.

I have been driving with the forward alert switched on on my XKR but having seen this thread and the price of the unit I have just switched it off!!

 

I'd have to check but I that part number looks like the steering wheel switch

From JTIS
Adaptive Speed Control Failure
"If a fault occurs during any adaptive speed control operation the adaptive speed control system will be deactivated and will remain in this state until the fault is rectified. The message center will display 'CRUISE NOT AVAILABLE'. "

A module fail should generate "CRUISE NOT AVAILABLE" and one or more of these codes P1571, P0567, P0570, P0569, P0566, P1697, P1696

FYI you can use the switch, radar and module from the latter S type and all but the switch from the last of the X's

All the revised part numbers are all the same
I research3ed this some time ago as I had to replace the radar. Aussie roads being Aussie roads it rattled loose and fell off. There are bugger all XJ's here and I had prices like those quoted. I eventually purchased and fitted one from the Stype

OH re retrofit yes it can be done. As sated you need to the radar, module, switch fot the steering wheel, trip computer switchpack (for the fwd alert)
I think earlier model had the alert switch on the switchpack with the heated seats though

Get most of these parts these from a late model S type. these are fare easier to find a generally cheaper as well. Once they are connected you need to enable the ACC option in the SDD

I suspect all cars a prewired as it was an option here in OZ that nobody really purchased. All were fitted by the dealer on delivery

That was certainly the case with my XJR

BTW I drive all the time on ACC. If you have the bumper off fit a tin plate to the offside of the radar. Extend the plate out as far as you can to the bumper. This blocks the radar beam on that side. You can adjust the angle to site. This stops the false triggers from the side and corners by blocking dome of the beam. IE making it narrower on one side

Cheers
3by151

 

So got new Unit for $700! Still trying to work out why this fault would cause restricted performance, been told that the can loop includes Transmission and ECU throttle response ETC so I cannot leave unfixed and just don't have cruise that I don't use anyway. Can anyone enlighten me to the reason why my car is held hostage by this stupid feature. Really don't want to drive around awaiting the Limp home message!

 

Rob the answers you seek are in the JTIS, no big secret

The STD cruise is handled by the ECU
The ACC is done the same way but also has the ACC module that feeds the ECU
This module process data from the radar, traction control and ECU.
It then feeds data back to the ECU emulating the STD cruise functions plus additional info for the TC and ECU

That is why a fault in the ACC module can send the ECU in to limp mode
Depending on the Fault a code is produced these codes can trigger
Red, amber and no engine lights with this light you will get one of
"Engine Systems Fault", "Restricted Performance", "Cruise Override, "Diver Intervene" or "Cruise Not Avaliable"

Its all in the JTIS section if you don’t have JTIS PM me for a link

Disabling ACC using SDD/Mongoose will take it back to STD cruise but you also need to unplug the ACC module

Cheers
34by151

 

Thanks 34, a million to 1 shot got me a brand new unit to fit so I should be ok, I agree with you that you should be able to bypass the ACC but why have the main dealer, an India shop and a couple of techs on here said that it is not possible? I thank you for thank you for the offer of the JTIS link I have tried it before but have MAC computers and it does not seem to work. I have owned Ronnie for 8 months and have Driven 1900 miles he has had new sway bar bushings a complete Transmission service, header tank,various other repairs and now a new ACC replacement, I decided this morning that when he has been repaired, enough and will be looking to sell even though it kills me to to it. My wife has an XK so I will have to be content with that.

 

As a fellow Lunux user I feel your WinDoze pain
Yep a mac is Linux, just open your terminal

To get around Windowze I use a WinDoze virtual machine. For Mac the free options are vmplayer and virtualbox. I'd recommend virtualbox.
Paid option is parallels. The cool thing with that is you can put Windoze apps on your desktop and run them from the mac gui just like an osx app

Re the ACC you gotta remember the dealers just follow the replace this abd pay me thinking. Do you really think they check out the SDD options and the electrical diagram?

If you check out the electrical manual page 36 section 03.4
You will find the Std cruise control has just the steering wheel switches.. These connect directly to the ECU

The ACC is on page 43 section 05.4
The steering wheel control still connects to the ECU but has the extra acc buttons enabled
The ACC module is connected to the ECU, Instrument cluster, Stability control and Trans via the CAN bus

The Enable ACC tells these modules to talk to the ACC module and the ECU to expect the extra switch

So when the module fails all the other generate faults giving your problem

So turning off the ACC enable stops them trying to talk to the ACC and no more faults
You need to unplug the module from the CAN bus to stop SDD detecting it

So looking at it in revers those that want to do the reto fit its all in section 05.4 of the electrical manual

Also if what the dealer told you was correct how is it that mt ACC was dealer fitted?
Is that not a retrofit?
If the dealer is correct and you cant disable as I describe how come my car was not in limp mode from the factory.
Well the simple answer is it was delivered with the ACC option off in the SDD

The dealer fitted the steering wheel switch, swapped trip unit (alert switch) added the acc module and radar then turned on ACC in the SDD

Cheers
34by151

 

It took me a while to get the laptop going, but I see 34by151 has pretty much covered it all!

 

Thanks all the amazing help as always, I am sure that this thread will be of great help to desperate owners in the future.

 

Good luck with locating one. There dont seem to be any on ebay at the moment...

 

I found a used one. Different part number but within my VIN range. When I install it I'll report back. Jag should be slapped for selling a rebuilt unit for $2700 but that's how capitalism works. Great way to generate repeat customers eh?

rcode

 

Used unit was damaged so I bit the bullet and got it from Jag. I installed it in < 15 minutes and of course had to have them program it. Couldn't stand resetting the warning screen all the time. Total cost $2570. Yes, I'm pissed!