I've been having some issues with my car lately. I have an appt with my local dealership next week to have them checked out but I wanted to see if you guys any ideas as to what the problems might be.
Quite a few weeks ago, I've noticed that during some cold starts, the engine rpm would fluctuate a couple hundred rpm's up and down for maybe 20 seconds, then coming down to a normal idle. I didnt give it much thought until 2 weeks ago, it was accompanied by a check engine light. So I decided to make an appt with my local dealer. They dont have any appts for 2.5 weeks, but I book it anyway. Meanwhile, I google the issue and found a TSB for this problem: https://www.truedelta.com/Jaguar-F-Type-tsbs-1173,2017
"NHTSA ID: 10110950
TSB ID: JTB00532NAS1

Situation: the engine may experience idle fluctuation during cold start. the engine malfunction indicator lamp (mil) may be illuminated with p050b-93 set in the powertrain control module (pcm)."

I figured no big deal as I'll just drive it as normally until my appt.
Then the next day I go in my car and see "low battery warning" on my dash. However my car started fine so I thought it might be a fluke.
That same day, I remembered that I have an old bluetooth OBD2 reader. I then plug it in and get the code, P050B, exactly as the TSB above stated.
The next day I go back to my car and the battery died and I had to jump start it! Upon some searching, I found the thread which states why the battery died: https://www.jaguarforums.com/forum/f...nd-fix-195551/

Okay so no big deal, I'll just unplug the battery and reset it. Thinking my battery issue would be over, yesterday I go back to my car and see another "low battery warning" sign on the dash, even though my car has power and is starting just fine. I also go into my phone incontrol app and find a tire pressure warning light is on, even though my tire pressure is fine and theres no warning lights on the dash.
And earlier today, I noticed my auto start/stop function doesnt work anymore. Normally I turn this feature off anyway, but I'd still like to know why it's broken!
Here's some background info on my car. It's a 2017 V6 base, bought it new in May 2017 and has about 5600 miles right now. I live in socal, where "cold" is 50F, and my car is literally garaged all week. I haven't had any issues with the car until lately.

 

Have you charged the battery since it went flat? These cars are quite sensitive to low battery voltage - it could have triggered the random warnings.

 

Your stop/start probably isn't "broken", it is meant to stop working if and when the battery is low on charge.

 

I've driven it quite a bit since then. It's started up just fine last few times, so I'm assuming the alternator has fully recharged the battery. Regardless, I'll disconnect the battery again to reset it, in case it wasn't fully recharged the last time I did it.

Good to know. I guess that's more of a symptom of the low battery warnings that I've been getting, and should be "fixed" when my battery issue is resolved.

 

Update: Just got back from the dealer earlier.

The check engine light for P050B was resolved. They said it just needed a software update in the ECU.

However my low battery warning still has no resolution. My car starts up fine and doesn't show the low battery warning anymore. Dealer tested battery and alternator. Both passed charging tests. Only symptom I have left is that my auto start/stop not working. However, I'll live with it for now as I almost always manually disable that anyway.

On the other hand, my incontrol app on my phone still shows TPMS malfunction even though the car doesnt say anything.

 

In the XKR forum you will find heaps of threads on electrical gremlins which all seem to stem from failing batteries. I've personally never had the issue with any jag, but a lot of owners use C-Tek charges etc. It might be worth looking through that forum to see if anything resonates.