hello, post getting an oil/filters change and ac evac (which turned into the place saying car needed $8k In suspension work lol, don't worry I know they're full of it)

I should preface this by saying the car battery voltage is good, tested good, battery voltage has been the cause of nearly all issues prior but not this.

the car immediately started having issues, alarm would go off every 20 minutes or so like clockwork, tried many things, battery disconnect for half an hour and reconnect couple times, isolated issue to onboard because when battery removed on key fob it would still continue to go off, at this point i know neighbors were preparing weapons so I just had to disconnect the negative terminal, I noticed on screen it said "alarm triggered by start attempt", finally figured out a semi solution which was to put the key fob in the car, lock it with manual key, the car detects key fob is inboard I guess and doesn't go off, car still locks externally with manual key.

took the car back, they looked at it with a big scanner, said they couldn't look further without doing further diagnosis with the super tech, and this couldn't be looked at for a few weeks due to holidays. he mentioned something about not fully being able to reset the car, needing the tech and higher level diagnostic tool (one he had was already like a mini briefcase size), and he did say something about seeing a push button start issue but he did not elaborate and said it could be anything else as well as there were a handful of codes on more advanced reader.

I would have been fine waiting with my temporary solution, however I woke up at 4am about half an hour ago to look out the window and see all the front orange peanut bulbs were on, and the rear brake lights were on, I went out to shut it off, stalk did nothing, no affect on the lights trying to turn them off, I disconnected battery and came inside to write this. battery no doubt near death, will put it on a charger, at a loss right now. this is dads daily driver and has had no significant issues apart from blower motor resistor, however it should be noted that the time I received an icarsoft LR2.0 for our 2 dailies, several months ago, I tested it on the XK, it did the methodical idling diagnosis, however the next morning dad was going to take it to work, the car did not start, I disconnected battery for 20 minutes, reconnected and it started again. I know they had plugged in a scanner for this work, towards the very end before picking up car, and I think that caused the issues, no idea the solution, help would be greatly appreciated.

canbus issue or something? please advice, should I try touching negative to positive terminals? that seems sketchy but some people have recommended it.

2008 XK NA 4.2

 

Your Public Profile shows that you're in Jacksonville, Florida, where the current temperature is 25°F. You said that you park outside. Your battery was already weak, and it was further damaged by the unusually cold weather. Even if you recharge it, it's been compromised by being fully discharged. You need a new battery.

New batteries can sit on a retailer's shelf for months discharging, so make sure your new battery is fully charged before you install it.

 

thanks for response, are you implying the rapid temperature change being the issue and not the overall temperature as a whole? just curious because i see so many people daily driving their XKs in the snow and I know we didn't get the worst of it, I also know my voltage was testing fine about a day ago, although I really wouldn't be surprised if this was battery related as you said either, although dad did say once he saw the lights on yesterday in a parking lot and went to turn it off before it stayed on long, but that could be chalked up to leaving it on the on setting by mistake and not auto. hoping a charge helps it and doesn't need replacement, but if it does it does, meanwhile I will try touching terminals soon to see if i can reset modules.

 

What's the on-load battery voltage (engine off)?

 

13.8/9
engine started 14.3/4 yesterday
I have not checked it since 4am when it did all that, I know without a doubt it sustained wear from the lights turning on whenever they did at night, i only looked out curious how it was outside and noticed it at that hour.
i'm going to grab voltmeter and check

 

??? Although it's Unusually Cold for Jack's Town, it isn't unusually cold for anywhere else.
Anyway, I don't seen anything about a Hard Reset. Although disconnected for periods, it MAY still help. Other than that, I have zero ideas.
Also, what's that "Intrusion/tilt" thing? I've not seen that before.

 

Your car is speaking to you. This is what it is saying:” HELP!!! My battery is very sick. It simply is not putting our enough voltage and as you can see, several of my systems are going berserk. Please charge the battery FULLY. I know tgat you won’t believe this but when my battery is dying I sound the horn, I flash my lights…it is a desperate attempt to get you to pay attention…PLEASE”.

The symptoms you describe are the classic signs in an XK of a failing battery. Yes, it seems counter-intuitive, but it is a proven fact.

 

you can yeah, for 10 to 30 seconds. nothing sketchy about it. not sure it will help, though.

 

Intrusion/tilt is the alarm that goes off if the car detects a tilt while locked such as tow truck trying to take it away. I believe letting positive terminal drain may have actually helped

 

I definitely believe you, seems 99% of the electrical issues are battery related, my battery was testing good prior to the lights turning on that night, at that point I knew for sure the battery was weak, I disconnected the positive terminal as well and charged the battery for a good while, I believe letting the positive terminal drain as well (until now I had only been disconnecting negative to get alarm to turn off) may have helped reset.

 

well, Merry Christmas everyone, seems car decided to channel its holiday spirit and stopped blaring the alarm after the final terminal disconnect for maybe 7 hours while I let the battery charge, I had only been disconnecting negative but I think disconnecting positive as well for a few hours made a difference, I kept waking up every hour or two last night to make sure lights weren't turned on, they have not yet, fob has also been inside the house since the car was used yesterday, battery did not appear to have a drain after charge/reset, although I did pull horn fuse, alarm did not seem to be going off, this is a huge change from the alarm going off every 20 minutes with fob in the house. I did order a push button start switch, and PCV valve which the car needed, I'll keep switch on hand and install to troubleshoot if the problem continues

 

I still can't help but see the glaring parallels between using diagnostic tools and security issues, like I said, months ago I used my icarsoft lr2.0(for the first and last time) on the XK just to have a look, next time car needed to be used it was immobilized, no start, had to disconnect battery for it to come back, has had no such issues again until immediately after they used the diagnostic tool on car before we picked it up, then the alarm started going off and car says "alarm triggered by start attempt" don't know what to make of it. I know the battery will be a year old this February, which is probably about the lifespan of batteries on our XKs, but the timing is just suspicious.

by the way, does anyone know if a new push to start cylinder switch needs to be programmed to the car? wonder if it could be related in some way.

 

These cars do have more battery problems than Midsomer has murders.
Are you charging the battery with a real charger of like 15 amps? My experience is a battery maintainer doesn’t do a good job for a full charging (they are fine to keep the battery topped off).
You might also double check ground points as they can get some corrosion. The ones in the front wheel wells are especially susceptible due to splash exposure. The attached diagram shows the ground points (g prefix) and there are lots of them!
Bon Chance!

 

No, the start/stop switch does not require any programming. It is a two minute job to remove the old one and fit the new one. Use some dental floss to grip the bezel of the old switch and just pull it out, disconnect, connect the old one, push it into place. Done. This is, however, not related to the problem you have been having. I think you will find that the battery is responsible for all the symptoms.
And modern Jaguars do not have more battery issues than other luxury cars. Every single luxury manufacturer sells the CTEK battery maintainer (at 3X the price) with its own logo on it, and they all do so for exactly the same reason: the electronic modules in modern cars need full battery voltage - and if they don’t have it, random, seemingly catastrophic symptoms crop up. This is not a Jaguar thing, but if it happens to YOUR Jaguar it can feed very nicely into the “Jaguar myth” that BMW owners love so much. On the other hand it can happen to your Mercedes, Maserati, Bugatti, Bentley, BMW, Ferrari or Rolls or…. And the appropriate CTEK maintainer with the pertinent marque logo is available for all of these. Much depends on how often the car is used and how far it is driven at speed (meaning not in stop and go traffic)..

 

.... Every single luxury manufacturer sells the CTEK battery maintainer (at 3X the price) with its own logo on it, and they all do so for exactly the same reason: the electronic modules in modern cars need full battery voltage - and if they don’t have it, random, seemingly catastrophic symptoms crop up. ... it can happen to your Mercedes, Maserati, Bugatti, Bentley, BMW, Ferrari or Rolls or…. And the appropriate CTEK maintainer with the pertinent marque logo is available for all of these). ... [/QUOTE]

 

Aston Martin seem to use these now (rebadged OptiMate 6) as that is what came with my Virage and it was purchased around 3 years ago.