I keep my car on a CTEK trickle charge when parked in the garage. I also have one of small emergency batteries that I stash in the door pocket. Can either use it to jump or just plug into cigarette lighter.

 

I've had my F-Type for almost 4 years now, and every time anything gets plugged into the OBD II port, the car's computer gets confused and says "low battery", as well as various other electrical maladies (warning lights, electric boot opener fails) appear. It's a software glitch that Jaguar is aware of, but so far has been either unable or unwilling to fix. It happened starting when I first got the car in 2015; of course the first thing a new car in MA gets is inspected, which, big surprise, involves plugging a computer into the OBD II port. Nothing happens immediately, but a day after I got the car home, it started with the "low battery" message. I took it back, they scratched their heads, claimed it must be a dead cell (in the brand new battery) and replaced the battery. Problem appeared to be solved. Then when I go for the annual inspection, same thing starts up again. Take it back to the dealer, they don't exactly say what they did, but it came back "fixed". Then I started tracking the car, and plugging a dongle in to feed data to a phone app for tracking performance. Same issue arose. This time I went on several forums, and someone said just disconnect the battery, wait five seconds, reconnect it, and it will work. They were right. So for the past few years whenever I get it inspected or do a track day (and use the app), bingo, "low battery". I just carry a 13 mm wrench in the glove box to disconnect the battery easily with. Real PITA, but nevertheless, a simple fix.

I've asked the dealer every year, when is Jaguar going to fix this? and they keep saying they're working on it. Their suggestion was simply don't plug a dongle into the port! I asked them what about inspections, and got a blank look; oh, yeah. Either it's an intractable problem or else not that much of a concern to Jaguar. But don't blame the dongle: it's faulty software on the car. They build beautiful cars, but the ghost of Lucas Electronics appears to still haunt vehicles made in the UK.

 

I'm trying to find the thread where one of our forum moderators disputed the OBDII plug in theory, but can't find it. I think this is truly an issue because I've had it happen. I though the solution was that the OBDII had to be plugged in and unplugged while the car was running, but can't recall. My indie mechanic did this on an inspection and I got the low battery warning. Did the battery disconnect and it fixed itself. Unhinged, do you recall the thread where this was recently discussed?

 

Think it was Unhingd and Brutal discussing the issue, IIRC. And I thought one solution is to be sure the application software disconnects or ends the session before unplugging the connector.

 

Yes. Brutal and I discussed the matter in depth by phone and he acknowledged based on my evidence that it was indeed a problem. He also thought he might be able to escalate the issue with Jag to isolate the source of the issue. Have not heard anything since, but since we all know how to manage the issue, I kinda like my kitty having an idiosyncratic soul.

 

I had this same thought after visiting both the dealer and a local tire shop. After the dealer had it to pull codes, everything was fine. The day after the tire shop had it the low battery notification came on.

It seems like there's some sort of application disconnect that needs to take place for the car to resume its sleep mode.

 

Most likely the dealer knew to disconnect and reconnect the battery after using the OBD port; the tire shop didn't.

 

The shop manual actually specifies that the battery should be disconnected during a software update and calls for an external power source to be used. I’m guessing a number of dealers don’t follow that guidance.

 

Ok, since we're down the road on this one; what settings info is lost or needs to be reset when battery disconnects. Doesn't the auto window up/down feature need to be reset on a disconnect?

 

I've disconnected the battery a few times now and the only settings I have lost are the one touch window up/down and the Trip A and Trip B figures.

 

+1. And resetting the trip display and the windows auto/up takes just a few seconds once you know how to do it.

 

If they did, it wasn't disconnected long enough to reset anything.

Yes to the window auto up/down. Mine also reset the instrument layout and interior lighting settings. The car was still new to me so I didn't realize this was the reason why there were no interior lights coming on at night when a door was opened. The reset actually did me a favor and made it useful again.

 

Likewise on the window auto up/down and tripmeter.

 

I found the window reset procedure (pg 139 of the '14 Owners Manual). No luck for the Trip Computer, unless its part of the menu? (looking on page 34)

Do the trip displays actually go back to zero on battery disconnect, or do they scramble? Is there a way to restore the readings that were there before?



If you had one of those old-time 'radio settings savers' (9V battery that plugs into a cig lighter/power point) would that keep the instrument memory alive whilst allowing the OBD drain to be resolved?


(Can anyone tell that I'm dreading our car's first required state inspection via OBD in August?)

 

I've never had an issue with state inspection, though it's possible my car doesn't have this issue. I've never plugged anything into the OBD port myself.

 

The trip readings will all revert to a full reset (zeros). The reset I was talking about was the trip display between the tach and speedometer. That will revert to whatever the default display and you have to reset to your preferred display via the menu and scroll buttons on the steering wheel. Any external power source most likely would prevent the battery management module from rebooting.

 

I had a check engine light come a few days ago so I scanned the code (O2 sensor) and scheduled an appointment with the dealer. Got up this morning to take the car to the dealer and found the battery to be completely dead, beyond the "low battery - start engine" warning. Had to use the key blade and unlock the car to jump start it.
Is there a proper OBD2 disconnect procedure? I can't imagine dealers disconnecting and reconnecting the battery every time they read a code and then re-configuring the preferential settings that get reset (or fielding complaints from people after every service about it)

 

I suspect it's device specific. Check your code reader instructions and see if they offer any guidance. Barring that, I can only suggest shutting the device off completely (if possible) before disconnecting from the port.

 

I recently had a dead battery - first I knew of it was when InControl rang to tell me! Seems the car told them the battery was flat. I think the problem was a module that wouldn't shutdown - I'd had a warning message about "SOS Sytem not available" for a few days and journeys weren't being logged on the Jaguar server. Jag Assist came to my rescue and jump started the car, after which I took if for a 45 minute run, and then charged the battery overnight with my CTEK. No more warning messages and journeys now being recorded again, so whatever caused the problem has apparently cleared itself. I now know the symptoms to look for if it happens again. Don't you love self-healing cars?

Forgot to add, nothing's been plugged into the OBD socket since last December (if then).

 

Wow.
Unbelievable!
It is now 2019, & This thread is over 3 years old, so I assume Jaguar must know about this issue for years & it's still not fixed?
I just had my 2017 in for annual inspection, went out of town for 4 days, came back to a completely dead battery.
Reading this thread was great, but still ticked off that we must disconnect & reconnect a battery to reset this supposedly extreme high-tech machine.
Even my VCR from the 80's had a reset button, so I don't have to unplug & replug....