I'm having an odd problem with my 2004 XJ8. Frequently the locks will stop responding to the remote. If I unlock the trunk with the key then the remote will work again. When this happens the light on the dash for the alarm has also stopped blinking.

In addition to the above there also appears to be a slow battery drain where if I don't drive it every day the battery will go dead. The battery is not necessarily dead, however, when the above problem happens so the above problem isn't just a function of the battery being dead.

Any clue what could be going on?

Thanks

 

My first suggestion would be to have the battery tested. These cars are sensitive to low voltage and your battery may be the heart of your problem. Get it tested first.

 

Thanks. Already done that and a brand new battery did not solve the problem.

 

Have you modified the car in any way electrically?

 

None what so ever

 

Do you know how to do a cold reset?

 

Slow battery drains can be tough to find. Somewhere I remember seeing that SOMETIMES this can be caused by a glovebox light staying on. You might have something entirely different, but try putting a video camera (maybe on your cellphone) in the glovebox & close it. Check the video to make sure the light went off. For that matter, you might try it in your trunk as well, to make sure the trunk light is going off. Good luck.

 

Are you locking the car ? They don't go to sleep unless locked.
Here's a pdf on quiescent current testing

 

I do not know how to do a cold reset.
I am certain it isn't the trunk or glovebox light staying on and, yes,
I am locking the doors.

Thanks for all of the replies.

 

Disconnect ground lead from battery
Touch disconnected lead to battery +ve for a few seconds
Reconnect ground lead.

 

O.K I've tried the cold reset. Is it supposed to set the alarm off when I reconnect the ground? If so I did as you said and I guess I'll have to wait and see if that solves it.

thanks again.

 

The theory behind the reset is to get everything on a clean slate. If your alarm went off I am not sure it was supposed to do that but for now let’s see what takes place. I would not attempt to do any troubleshooting until you know that you still have a problem.

 

I posted a few articles on the same issue a while back, e.g., "1: article headed something to this effect: could my LED parking lights globes be causing battery leak..." + another: "parking lights come on when I unlock the car" + another: "car satellite tracking device interference with electronics etc". Bottom line, check and ensure that:
1. your battery is not old and needs replacement
2. Your security satellite tracking device's internal battery is not dead therefore slaving off your car's main battery power
3. Your parklights don't do funny stories like mine where they'd come on even if the switch is on the off position when I unlock my car. This looks like there is an electrical short-circuiting going on which I'm still battling to solve to date. My lights go on by themselves even when the car's door is opened and or the car is shaken! Imagine what happens after dark when no one is watching my car and the spooks and aliens start dancing at parking lights that come on all by themselves!

I'll soon be booking in my old lady for an annual check up and service, and I can bet my bottom line dollar that the Jag garage service workshop will cost me an arm, a leg and some sanity.

Good luck

 

How do I check to make sure my security satellite tracking device's internal battery is not dead therefore slaving off your car's main battery power

 

At least one of two ways:
1. If the tracking device is older than 5 years, then it's more likely that its internal rechargeable battery no longer rechrages when your engine starts running. Remember the device is always on sending signals to your security company's central tracking tower, whether or not your car is in use. It has its own battery to power it up and to allow the car to be tracked evenif your car's main battery is dead. It then gets charged by your car's main power battery when it reaches a certain level. It acts like backup power.
2. If in doubt, go back to your installer and ask them to confirm that your tracking device that's hidden somewhere in your car is not broken and or battery dead.

Good luck

 

Call me dense but my installer is the jaguar factory as the only security system I have is the factory installed alarm. This sounds like something aftermarket of which I have none.

 

I too, was perhaps wrong in assuming that tracking devices are mandatory where you are. In my country, theft of cars is so rife that if you want your insurance premiums lowered significantly, the car wouldn't leave a dealership without having installed a Jag approved satellite security tracking device. Do you not have such a device installed? It has its own fob which allows you to either set it on or keep with you so as to send signals to the box in the car which in turn sends signals to the control tower.

If you don't have this, your issue could be due to something else. I had a similar problem, replaced batteries and the problem persisted until we checked this device.

 

You will need to measure current drain using a meter as described in the pdf.

 

+1

 

O.K., since my last post I've done the cold reset and that didn't work so I took it to the dealer and they tested it and said I had a fuse box the had a cellenoid sticking so they replaced that. Still no luck. Back to the dealer. They tested it again and said I had a bad battery (even though it was a brand new battery) so they replaced that (plus the 4+ hours of testing) and....wait for it.....stil njo luck. Their brand new battery still died. So now I'm at a loss. The other odd thing that happens is once in a while I'll go out and the remote won't open the doors. However, once I unlock the car with the key the remote will work fine. This is leading me to believe something goofy is going on with the alarm that is causing both issues.