I had to replace the original battery the middle of this year because I kept getting Low Battery warnings and it finally died.

I learned on this forum about the issue with the hazard light staying on even after I double-locked the car, and that matches the symptoms mine was having. The door lock LEDs and the hazard flasher would both stay on indefinitely after locking the car, and then I'd get the Low Battery warning on the dash.

After I replaced the battery, that went away until about a week ago when I noticed the hazard light on again the following morning (it was probably on the night before after I'd driven the car but I didn't notice).

I've also read something being plugged into the OBD port can trigger this, but that hasn't been done on mine. It hasn't been serviced since I replaced the battery, nobody else drives my cars, and I haven't plugged anything in to the OBD port. The only thing I can think of that might have triggered this again is a Lo jack system in the car. I don't know enough about that system to know if it uses the OBD for anything.

I've since bought a Battery Tender Plus I'm using to try and maintain it, but it's a pain because I have to take the stuff out of the trunk to hook it up. And, I can't hook it up anywhere where I work.

I searched the forums here, and it doesn't look like Jag has fixed this problem? Does anybody know if they're actually looking into this problem, or is it just something we have to live with, and keep maintaining (or buying) batteries?

 

I have not seen any reports of Jag addressing this; we all must be imagining the problem. That is sort of what they told me. I wouldn't worry about it while you are at work, but you can lead the pigtail from a maintainer up from the battery compartment to the top back of the trunk floor so that you can plug your maintainer in at home without emptying the trunk. That is what some of us have done.
Larry

 

The solution is to disconnect the negative lead to the battery for at least 10 seconds in order to reset to energy control module. If you then ever get a low battery warning in the future, you have to do it again. For me, though, it only occurs after the OBDII port is tapped into.

 

Yep; I have a pigtail that has a couple feet of wire attached and I simply plug my car in at home. I've not had any issues lately and even on a multi-day road trip but I keep the battery on the tender most of the time. When I first bought the car (used) it had been sitting on the lot without a charger and I had some week battery symptoms but nothing since. My car tends to sit for 4-5 days at a time during the summer and for 6 months over the winter.

There is so much electric "goodies" on cars nowadays that I plug them all in unless they are being used as daily drivers.....the wife's SLK gets plugged in too.


Dave

 

I've never had this issue. The only time that I've ever seen the low battery warning was at the beginning of the test drive. The car has been in for service a couple of times where I know that they hooked up to the OBD port. Maybe they disconnect the battery afterwords. They did leave some evidence of that once since they left the piece of flooring that covers the battery off.

 

An easier way to connect your battery maintainer/charger, if you are still using clamps rather than a pigtail connector, is via the under-bonnet power terminal. This saves having to empty the boot (trunk). This is the way I do it, and when I remove my set of pigtails from the other car I will attach them to these points, but in the meantime I use the clamps on these points. I attach the earth lead to the large bolt you can see near the bottom of the second pic.
Here's a couple of pics:

 

I've not had any problems with power since a software update but I note that when I connect my conditioner, it reads as a low battery - not impressed as my 8 year old daily driver Audi TT, with the original battery, which also uses the battery for a variety of purposes, reads healthy.
Saying that I've a number of electrical glitches that will need taken care of next time I go to the shop so maybe there is a hidden drain on the battery.

 

What are the glitches?

 

The glitches are as follows
1. Variably need to place keys under dash to start despite good batteries in the keys
2. Dash vent not always responsive
3. Auto restart on stalling often doesn't happen (I stall more often than I ought as I need to reverse over a high lip into my garage because of the angle of the driveway and the car often gets caught on the lip)
4. front park sensor works half the time (despite putting it in reverse first)
5. New TPMS monitors are not sync'ing, though this may not be the car
6. A new problem that I do not think is electrical is that on high blow the fan has started to make a very high pitched whine.

In fairness, I am awaiting a new electrical harness following identification of a problem linking the phone into the system a few months ago - I live in hope that the 100 day build will not be delayed.

 

Ouch! Wishing you a successful transplant of the central nervous system.

 

I like the CNS analogy. At the end of the day, none of this affects the great drive. The sun was out, the top was down, warm hat, gloves and sunglasses were on and the winter tires were sufficiently responsive to enjoy. I even had the chance to parallel an i8 for a couple of miles and realize that I really do like my F type far more.

 

Great attitude and I'm not much of a complainer myself, but #1, 2 and 3 would have me marching down to the dealership.

Cheers,
Dave

 

This just started happening, and was going to start a new thread, and voila... thank you forum & community. The Waylens OBD receiver was used for the first time a few weeks ago, and since then the door light LED and the hazard button won't turn off. I can't be 100% positive the OBD is what triggered this behavior, but I had never noted this condition before this.

Now I have the low battery warning. I'm at 23K miles in <1.5 years and my dealer has been a good friend.

I will try this fix.... unplugging the negative lead to the battery (assuming it's the main battery and not the secondary one?)...

But has anyone had a dealer fix it in any way, esp. under warranty?

Also.... what's the time frame between seeing this warning and actually having the car die? Quite annoying. Don't want to be stranded tho I do have one of those remote control sized jumpers. So cool.

 

When the Energy Control Module is not working properly the car can sit for 2 or 3 days before the battery totally dies, but the battery warning light will come on overnight. Since I don't have the auxiliary battery(MY 16+), I don't know if that has to be disconnected as well.

 

Okay... I'll bite. There's a lead acid (main) and lithium (starting the car) battery. I'm going to do this now to prove I'm not a pencil pusher idiot, but I wouldn't mind a little help written out.... I've also noted that you're not supposed to jump the car directly from the battery, either?

But It's basically: take out trunk stuff, on left side of trunk, there's the battery. Unplug for a bit, voila. That will resolve the low battery indication?

So is this a electronic glitch where the battery is actually fine, or is it truly that the battery is bleeding and the indication is correct? Unplugging means it makes the glitch go away and resets the battery, or is the battery really dying?

This is like that scene in office space where they say "so you fired him?", "Ummm, no. We fixed *the glitch*".

lol

 

On our cars with two batteries, I'd disconnect them both.

Dave

 

No problem with the battery. Disconnecting the power from the car essentially reboots the Energy Control Module (ECM) that somehow goes wonky sometimes when the OBD port is accessed. As a result, various parts of the car, including the button light for the hazards and other courtesy lamps remain on, thus draining down the battery. Since I don't have the secondary battery, I just have to reboot by disconnecting the ground (or earth ) lead from the big battery for a few seconds. It's actually easier to just disconnect that lead where it bolts to the body on the bottom of the boot.
TRy disconnecting just the big battery. If it doesn't resolve the problem, you may have to disconnect both batteries at the same time for a few seconds. The hazard button remaining lit for more than 5 minutes after shutting down and locking the car is a clear sign that the ECM needs to be reset.

 

I will certainly be taking it up with the dealer but I know they will tell me to wait for the replacement harness to come from Jag and it is a nuisance to get to the dealer but most worrying - I don't want to give it up to the dealer until I have to

 

It is pitch black, but I am going to see how it goes right now. About to park at an airport for long enough that I would be concerned. I had never even thought how annoying this would be for people that aren't daily drivers.

Thanks.

 

Well that was certainly the simplest thing I've done in awhile. So fixed the glitch, but now the windows won't auto roll up. They still auto roll down, but you have to hold it to make it go all the way up.

Also can't find how to change my dash controls where the speedometer, etc is. No biggie. I am sure there's a way to fix the windows, too.

Also wonder out loud if you can make the driver side mirror dip just like passenger side for parallel parking? I know I'm OT.


But does this glitch happen every time the OBD is inserted? Has anyone tried to get the dealer to address it? Sort of annoying to have to do every time I shoot dashcam footage.

Thanks tho.... OBVIOUSLY we know who's a big helper here, LANCE. Cheers to you. Fantastic. Actually to all of you.... we're like a super-consciousness hive mind here. It's almost distributed ESP to make nervous dealers itchy. LOL Most good dealers embrace forums, of course.

Also.... I just did the main battery, not second battery. Immediately rebooted within 8 or 9 seconds, the door LED went off immediately, and the hazard took about 3 or 4 minutes. THANK YOU!