I have a 2018 F-Type R Dynamic that we purchased in July that the battery keeps draining after it sits for 3-4 days in our garage. They said they fixed it the first time and it failed a few days later. We brought it in two weeks ago and they called and said it was ready after 4 days. We told them it needed to be 100% right because if not we would go the lemon law route which in Oregon if the same issue arises 3 times you can proceed with the lemon law process.

Well after a week and a half later they just called and said it was the Telematics ECU draining the battery and they replaced it. Has this happened to anyone else.Just a little gun shy as we spent a lot of money on a car that has us nervous of driving only to be stranded with another dead battery. Thanks for any input.

 

I doubt it's the "telematics ECU". More likely the same glitch that causes the battery control module to go wonky after the OBD port has been accessed. A simple disconnect of the battery for about a minute will reset the module and resolve the issue until the next time someone plugs into the OBD port with a diagnostic or programming tool.

 

They replaced the battery the first time and said that was the problem. After I got it home I did the battery reset and it still went dead a couple days later. I feel like they are throwing darts at a dart board trying to see if that fixes it. It just makes us nervous taking it anywhere down the road. We only have a Land Rover dealer here in Portland that absorbed the Jaguar dealership in town. Not too confident with them so far.

 

I had this problem. I disconnected the battery twice, and it kept doing it. Then a week later, it fixed itself and it's stayed fixed.

 

Thank God I did not fitted the OBD2-plugg to use with my Torque app, or I'd have a drained battery too... Does JLR do this on purpose to prevent you from looking into the system ???

 

Same thing just started happening to me, out of nowhere. A couple days ago, I walked into the garage and there was a faint dinging noise. I looked at the dashboard and there was a warning light “Battery Low, Start Engine.” So I started the engine and let it idle for 10 minutes. The next day (or second day), same thing. I had to go somewhere and drove 100 miles. We’ll see what happens. I’m hoping it corrects itself too. It worries me too because there are areas on the highway where there is no shoulder.

I bought the car in 2017 with that problem. The dealer changed the battery and the problem was resolved. Since then, the OBD port was accesses a couple times. Year and a half later it’s happening again

So I think I’ll disconnect the battery.

Another thing: Is this a false warning, or is the battery actually being drained?

Another another thing: I leave the headlight switch on “Auto.” No problem, right?

I feel ya, but its good to know I’m not the only one experiencing this.

I’ll keep y’all posted.

Edit: How do you disconnect the negative terminal? There seem to be a lot of things attached to it. There’s that copper looking thing and a black plastic thing to the side. Do I still just loosen the nut and pull up?

 

 

• NOT A FALSE WARNING. Battery will not be strong enough to start car after being parked for 48-72 hours.
• I leave my light switch set to auto and never touch it. No issue whatsoever.
• Disconnect the ground lead where it bolts to floor of the trunk. Easiest way to do it...nothing in the way.

 

 

It's a brand of battery charger, one of the better ones and used by many forum members here. https://www.ctek.com/au

 

 

If I look on the link, its a 15A charger.. .. you don't need that to 'trickle' charge a stationary car ! I bought a $ 19,50 12/24V 1,5A trickle charger and have been using it for years,
on my Discovery 3, Iseki mini tractor, LR2 and so on, and its fine ! You don't have to fork-out $ xxxxx amounts to solve this problem ! Yes, there is no handy fixed connection,
but when I store the car it stays for months at a time. Fixing is 5 minutes ; lead it through an opening that doesn'n clamp the wires [eg shutting the hood ]. No problemo...

 

Ah, but the CTEK isn't a trickle charger - it monitors the battery state and applies whatever type of charge it deems necessary. That way it maintains your battery at optimum efficiency, no risk of overcharging.

 

 

Same with this device. I simulated the [dis-] charging with a lamp. Connect a powerful lamp and measure the voltage ; exactly at 13.0V the charger switches on. I removed the lamp ; at 14,4V it stopped charging. No sweat, no cost too..

 

Well, I went ahead and bought the CTEK MUS4.2. I appreciate the help.

Now can I sit in the car and listen to radio without the engine on as long as the CTEK is plugged in? At the moment, it goes into power save mode and shuts it down after a few minutes.

 

No, it won't help you with that.

 

Dang.

I don’t think I’m the only one who likes hanging out in the car just to listen to music or watch a DVD. It would have been nice for a passenger waiting in the car. Kinda self defeating huh? I always wanted to mention that.

Oh well.......