G'day Mates!

I have a "new" 99 XJ-8 VDP.

The drivers (only) window does not operate properly nor does the sunroof.

The window will not go up/down although I hear the "click" when I push the button. The sunroof opens but then closes itself after 15 seconds. Same thing when tilted.

I "rebooted" by disconnecting the battery for 30 minutes and all was fine. It did not last long though, within a few hours I was back to the same issues.

I'm hoping someone has some insight into this problem.

Thanks and Cheers!

Tom
tomtomterrific
Jaguar Conservationist LI NY
currently own (2) 99 XJ-8 VDP's

 

Try the "Hard Boot"...

My windows were confused too a few weeks ago. Following Brutal's advise here's what I did.

Disconnect ground cable (- side) from the battery and then touch it to the Positive Post on the battery and hold it there for a few seconds.

Nothing is going to fry and there won't be a spark. This will clear any bad memories by completely depleting voltage in capacitors within the modules.

It worked perfectly for me.

Ken Wolkens

 

Thanks for posting this fix.
I was ready to order new module, window motor switch for sunroof.

This took about 2 minutes and fixed the window and the sunroof.

Thanks
Mark in Destin
99 XJ8

 

I was told by my dealer that the sun roof rails were bent and they would have to order from the Uk after I asked my bank manager for a loan .... ha ha. This did not make any sense to me so I stripped the door panel and removed the window computer. When I saw the warning that this part is programmable the "light" went on. I disconected the contacts, reconected did a hard boot and its been working justfine for the last year or so.
Regards
Gareth
South Africa

 

Hello and this is my first post. I have to say that this forum is really inspirational for self-helpers.

My question is about the "hard boot". Once you disconnect the negative cable from the battery and then hold that same cable to the positive post on the battery (for a few seconds), does this action remove all the prior programming to EVERYTHING? Are there any side-effects to doing this? Do I have to reprogram the memory in the radio, the seats?

Thanks!

 

You will not have any side effects. You are not crossing the poles of the battery. You are grounding the positive post to the frame of the car.

I did it on my 99 xj8 cleared the fault and windows and roof work great. Saved me about 350!!

 

HI Tempest

This will only require the code for your radio to be entered.
Regards

 

Thanks misham64 & garethww for that clarification!

I'll do some more research on the radio code issue as this is a used vehicle with limited documentation.

Cheers!

 

I'm looking forward to trying your solution as I have the same window/sunroof problem. Only hitch is: how do I retrieve the radio codes before I wipe the memory?

 

Quick call to your local Jag agent - parts dept. Give him the last 6 digits of your VIN number and he will give you the code.

 

Thanks for the reply. Unfortunately my closest Jag dealer, besides being 45 min. away, is not as friendly as they are across the pond. They want me to set up a service appointment just to retrieve the code. And to add insult to injury thats a minimum of $121 USD, just to come in and show them my title and let them look up the vin. I'm already quite frustrated with them for when I had to get another key for it. Seems the service manager double booked me and when I went in for the programming I had to wait an hour and a half past my scheduled appointment before they even pulled my car in! Needless to say, I'm really not interested in doing any more business with them if I can help it. Jaguar service has left a real foul taste in my mouth, I don't care how nice their waiting room is.
So, as you can see, I would prefer another solution.

 

thank you all for the great disscustion on this. I was resetting but I'll try the hard way, tonight.

 

If you didn't talk to the parts counter, you will get the response you just stated. If you don't get satisfaction from that dealer, call one of the dealers that participate on the forum. It doesn't matter where you live, this can be done over the phone.

 

Thats a shame about your dealer -- the one I use in NJ is very nice. The parts guys are very helpful.

And the sunroof will reverse if it is not lubed or the wrong lubed is used - the motor has force control.


I still would be afraid to touch that ground to the battery

Some of that stuff still says Lukas

 

If you have a problem that matches others on the forum. It is the same fix. Window & sunroof problem at same time. Not a coincidence. Computer ties both together. Do the simple hard boot and problem will go away.

This car is not your grandmothers Buick. If te sunroof opens then closes after a few seconds it is a computer problem not mechanical.

Many have done the hard boot and fixed the problem.

Save yourself time & $$ try the fix you read about here 1st. If that doesn't fix it then look at other options.

Hope this helps.
Mark in Destin

 

Just got a chance to try the hard boot and it worked for me. Didn't have a problem with the radio either. Never did get a chance to try the dealer again for those codes. I've been busy replacing the upper chain tensioners. Glad thats done. I just figured I'd give the "boot" a try and it worked great. Thanks, guys!

 

Thank You (all) for this information - this repair worked like a champ! CB3 for my 1999 XJ8L

 

Thank you for an easy fix. I followed the advise to touch the ground to the + pole on the battery and like magic the window and the sunroof now work on my 99 XJ8.
Mike

 

I'm lost on hard boot idea. Is (+)positive side still connected during this procedure. please wxplain

 

I'm glad you asked BEFORE you tried it and got something wrong. While it is very easy to do, getting the connections wrong can have catastrophic/dangerous results, so here is how it's done safely.

1. Turn Key OFF
2. Remove Negative Battery Terminal from the Negative Battery Post (10mm Wrench)
3. Turn Key ON
4. Touch Negative Terminal End to Positive Terminal End and hold there for 15 'ish seconds (Positive Terminal will still be connected to Positive Battery Post)
5. Turn Key OFF
6. Reconnect Negative Battery Terminal back to Negative Battery Post

NOTICE: On First Start after the Hard Reset, let the car idle for a minute or two without touching throttle. This allows the computers to recalculate the throttle position, etc... Also, the car may drive differently for an hour or so while it's relearning your driving habits.

See Attached Photo showing Correct Short for Hard Reset
NOTICE: NOTHING CONNECTED TO NEGATIVE TERMINAL


PS: My window stopped two days ago, so I knew I had to do this anyways, and thought I'd post a photo for clarification. Window works fine now.