I purchased a 2007 XKR convertible last September. It ran well during the winter on a weekly 50 mile run but has given problems since the spring with greater usage.

The problem seems to be stemming from a large, intermittent, power drain which depletes the battery and stops the ignition process. The tail lights come on and stay on and I can't get ignition. I have been assisted by a local Jaguar specialist who has had the vehicle for short periods. Boosting the battery and clearing the faults on the fault diagnosis computer has allowed the car to start and run perfectly. I then run the car for around a week and then the fault seems to recur and I can't get ignition again. During the periods that the car was at the workshop (after being started at home and driven there) no specific power drain was identified, suggesting an intermittent fault. After the last workshop period I ran the car faultlessly once again for a week then the problem occurred again. Today the battery boost and fault clearing did not work so presumably the fault/power drain is "in operation". The mechanic has taken away some fault computer output and is giving some thought to the issue. Does anyone know if there is a common 2007 XKR convertible fault that causes this problem or does anyone have advice as to how best to identify the source of the power drain?
Many thanks
ALLEN68

 

Your symptoms sound like the battery is toast, too low voltage/amperage to run the electronics properly. If you do a "search" on this forum you'll see pages upon pages of similar electronic gremlins that arise when this happens. Get yourself a new battery, preferably an AGM, then make sure to put that on a good quality charger or maintainer to bring it up to 100% capacity (no new batteries are not at 100%), clean the battery terminals well, and yo should have no further problems. The majority of people here believe that a battery charger (Ctek or Deltrans Battery Tender) are a wise investment, I am in that camp as well.

Even if your battery is newer if it has been discharged to a low point there is likely damage done to the cells such that it cannot be brought back to a level enough to work properly in this car, if it is an older battery consider this preventative maintenance and likely the cure to your issues

 

Yes, it is a faulty battery, not a faulty car. New battery, fully charged will cure this problem but unless you use the car very regularly and for runs of a decent length, you should invest in a CTEK battery maintainer.

 

Agree with all advice given. Replace your battery. Get a maintainer and use it. Do you have to plug it in daily? NO! but I do and have not had an issue since. These cars must have a battery at 101% charge at all times.

 

Yes, my vote is a new battery and a CTEK maintainer.....

 

Allen68 - Got your new battery and CTek yet? If so, what are the results? By the way make sure you charge the new battery as most new batteries are delivered only with a partial charge.

 

Many thanks to all who have responded to my posting. The problem is still ongoing but here is a bit of a status report:

As suggested in the posts, a bad battery was indeed an original thought. However, prior to my original posting on August 1st, I had already installed a new battery and purchased a CTEK MXS 10 Battery Conditioner. All was well for one week before the ignition problem struck again. The problem occurred after the CTEC had been on over night and was steady in phase 7. Prior to taking the car out I opened the boot to disconnect the CTEK and the tail lights came on. This always precedes the problem and is indicates a low battery I am told. I was not surprised that I could not start the car when I tried.

My Jag specialist came out and was unable to start the car with the new battery fully charged and his 'industrial' CTEK in is supply mode....and with a battery booster pack connected. The diagnostic computer indicated that the voltage available was 13V.

He brought in an electrical specialist yesterday when I was away and managed to get the car started. They believe they have tracked the problem to a "fault in the dash pod"....That was the message my wife relayed to me. I'm not sure what the dash pod is, but they have taken the car and will feed back after some more work.

I am still feeling that there is an intermittent fault or failing part that soaks up enough power to cause the system to turn on the side lights, stops the ignition cycle and cuts power to things like the head lights, windows, indicators, etc.

I will hopefully be able to report on a more descriptive, and hopefully a more permanent, fix in the near future!!
Regards and thanks again.
ALLEN68

 

I still have the spurious ignition problem three years on and there appears to be no sound diagnosis. Periodically the side light come on when I unlock the car and the ignition sequence will not activate. I now cure the problem by beating on the top of the instrument panel. The instruments flicker and the car will start. All stored date (MPG, Trip Miles, Clock, etc.) go to there default settings. There are generally a few fault messages which disappear after a few driving and shut down cycles. Occasionally the fault occurs while I am driving. Speedo an Tacho freeze, indicators and lights don't work, CATS system fails and many other issues.....but the car drives normally. A tap on the dashboard revives things! Clearly there is some sort of electrical fault but my mechanic (a jaguar trained specialist) is stumped. I just thought I'd add an update to this string just incase anyone has any new ideas.

 

Maybe a bad connector or dry joint (i.e. dry solder joint).

If it causes enough hassle go hunting.

 

If hitting the top of the instrument cluster seems to give a temporary fix, I would pull the cluster, (which is very simple to do) and check all the connectors for any corrosion, bent or broken pins, pinched wires, connectors locked in place correctly, ect. Also might look into what a used cluster would cost you through eBay or salvage yard, assuming you can have it programmed to your car. Some of the guys that know more about programming could chime in to let you know if that is an option or not.

 

hey that's how my dad fixed the reception on our old Admiral TV! Seriously though, when you say bang on the instrument cluster, are you referring to the area right above the gauge cluster or above the center console. Might narrow down where to look. Guessing it's the former...

Also there must have been some codes or clearing it wouldn't have had an impact.

 

The cluster is the brains of the chassis and is VIN locked to the engine ECU so swapping isn't a viable troubleshooting technique. I popped a spare in and got a VIN mismatch error on the cluster screen. As said above, pop the cluster out. There are two multi connectors that plug in securely. Inspect them and pull the cluster apart (little torx bits if memory serves). I have pics in my build thread from changing the gauge faces. 99% sure your problem is with the cluster or connections.

 

As per Ranchero but also look at the wiring diagrams How-to sticky post #3 and locate the ground/earth points that feed the cluster. Most of the ground points are on the magnesium alloy dash structure that corrodes over time.

 

Bad grounds are a very common issue with older cars. You can spend a lot of time chasing and cleaning the various ground connections throughout the car. Better, cheaper and easier just to add a new ground wire to the offending component/area.
My understanding is that Jaguars have a parasitic electrical draw from various capacitors; and that one should not only lock the car when leaving, but also push the lock button twice to reduce this draw.
The old fashioned way to isolate an open circuit is to first measure battery draw down, and then remove various fuses. to isolate the bad circuit. Once the circuit is isolated, then start unplugging electrical connectors in that circuit, once again observing battery draw down. Usually, a fault is not in a printed circuit or a break in wires, but rather at a connection point. Jaguars have benefited greatly from Ford, and its electrical components are now as good as any mfg. But, in time connections can loose connectivity through air-borne corrosion, particularly near salt water. Sometimes, a wire at a connector is a bit loose.

 

Earlier this year I blew probably twelve fuses on my multimeter doing current draw testing on my F150. The battery would get perilously low over three or more days inactivity.
The trickiest part is setting up cables and such to get the meter leads between the battery post and battery cable when disconnecting the two, without losing power to the vehicle. Then of course when you pull certain relays and then reinsert them, power comes back regardless.... and *POP*. There goes another fuse.
I got tired of it and got myself an inductive pickup ammeter that clamps around the battery cable. MUCH EASIER!!! A bit more $$$ than a typical meter, but well worth the $80+ price just to save the aggravation.
There is also the "Voltage Drop" troubleshooting technique, testing the millivolts between both posts of each fuse and reference a chart to see which fuses are carrying what amount of current.