The auto stop/start quit working all of a sudden. The other day, at a stop, it worked; but again today, it is not working. Personally, I don’t like the auto function at all. But, should I worry that something else might be going on and therefore take the car into the dealership to see what is going on?

 

Lots of reasons for it not to work, including too much difference between set cabin temp, and actual. In my case the system is disabled because the little aux battery is dead, lost a cell so it’s reading 10.5 volts or so. I’ve also seen it disabled because the main battery is weak.

Suggest checking the voltage of both batteries at rest, engine off.

 

It's also an indication of the charge on your battery. I found the ECO works all the time when I put a lot of miles on the car during the week. But if it sits for a week or two it takes some driving around before the ECO starts working again.
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Your local shop should be able to verify operation and also what is inhibiting eco from working. A multitude of checks must be all set for eco to work. On a hot day and above average climate need, car not in closed loop, battery voltage in either battery e=will cause eco not to function. If you're concerned about it, I would bring it in. I personally hate it, but that's just me.

Rummy

 

For all you blokes who hate the stop/start system (count me as one!) and who have the older dual battery system, it is a doddle to disable it permanently with zero side effects.
Simply unbolt the end of the earth lead (which runs from the negative terminal of the secondary battery) from where it bolts to the floor of the trunk (boot) and zip tie it up out of the way so it can't contact the bodywork.

 

Clubbirth, We just installed today a new EK151 battery that came to us here in the USA from Europe. It is possible that if we run around a bit it, the new battery will start to
work for Stop Start?
Sincerely, Jim and Gwynne

 

I don't know if this will help.

I took my wife's F-Pace V6 in a couple of weeks ago for its annual service, and mentioned that the stop/start wasn't working. When I collected it I asked "you just slapped a new aux battery in I guess?" "Nope" came the reply "Reloaded the software with the new version"

Stop/start now works!

wombat

 

I will check on the new software if it isn't working in 7 to 10 days as suggested by XJsss. Thank you for the suggestion, Wombat.
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No software update is needed. If the stop/start is not working that's telling you the system is not fully charged and it will turn off the stop/start until the battery capacity increases.
What I have found is leave it alone and put some miles on the car before thinking there are any problems.

The BMS (Battery Monitor System) needs to be reset when installing a new battery but that's not really true. If you read further the system actually re-calibrates itself automatically
over time. Even if you don't change batteries. So again give it more time before a dealer visit.
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@James37 I've ordered a battery through your recommended link and will report back on the outcome. Thanks for doing the legwork!

 

clubaith1,

We have owned our 2017 V6 F-Pace for 8 months, The stop/start system didn't work at any point between purchase (CPO) and its service 2 weeks ago. After the software update on the "gateway module", no new battery fitted, the system worked perfectly straight out the blocks.

wombat

 

That's new one for sure!
Do you have a code ?
I think it must set something so the SDD can tell the tech what to do?
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Sorry, the invoice just states 'read and clear fault codes'. it doesn't actually state which codes were present.

wombat

 

Here's a thread that may help https://www.fpaceforum.com/threads/a...lusions.44909/

 

Oops! I missed that you have a F-Pace.

Sorry I know nothing about the F-Pace.
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I found this for the XJ. It's not fitted on my 2012 XJ.

https://static.nhtsa.gov/odi/tsbs/20...96504-1020.pdf

 

XJsss Sounds good! You are most welcome for the legwork. I am grateful to you and comb and all the others who have told me what can be done.

 

Yeah!! Success! The Stop/Start is working again! Today Gwynne my wife was driving the 2014 XJL and the Stop/Start started working again, just three days after we had it installed.
My deepest thanks to all of you who gave me such good advice, including Comb, (spelling?) XJsss, and Clubairth1. We have the satisfaction of fixing it "ourselves" and a savings
of around $400 over the dealer estimate. Gonna go out and buy a new lawn sweeper with the savings. Thanks again everyone!
Jim and Gwynne in Dakota, Illinois USA 2014 XJL, 2010 XF.

 

James47,

Delighted you got it fixed so easily and didn't need any software updates!

Perhaps we should start an IL XJ owners club?

wombat

 

I recently had the same issue with my 2013. I swapped out the auxiliary battery and thought everything was ok, but 2-3 weeks later the same issue occurred. Here's what else was wrong, the auxiliary battery charging relay was bad, after that was replaced by the dealer the start/stop function has worked correctly. I'm not sure if the other battery was really dead, or it wasn't getting a proper charge, thus the stop/start problem.