It's a long story, but the short of it is that I'm making arrangements to sell our 22016 XJ-L. Here's the problem.....In order to bypass the annoying "start-stop" feature, the dealer showed me how to simply disconnect the auxiliary battery, which disables that "feature". Everything has functioned just fine, except that the yellow, "eco off" light on the instrument panel stays lit, rather than turning green, in it's normal mode. The auxiliary battery has been unplugged for 8 years, so I'm assuming it has lost it's charge.

If I take the car to the place I'm selling it, obviously the light will be on, and it will be noticed, causing an issue for me. Can I simply charge the battery and hook it back up? At that point, will the car's system take over charging it, and I'll then be OK?? Will anything have to be reset?

Thanks for any input you can provide!!

 

When battey have been sitting 8 years without charge, its gone for sure by sulfation effect. You need to purchase new battery and after you fit it the start and stop should function again..

 

Thanks for the info, however I have a question. Is this a simple R&R operation, or once I swap the battery, do I have to go through some sort of process to get the car to "recognize" the new battery?

 

remove and replace light will go out, there is a procedure for resetting battery replacement, but you'll be fine,

 

Thanks, "Ian", but now I feel like a fool, as there is not a second battery in our 2016 car. I just came from the garage, as I was assuming to see the auxiliary battery, stick my volt meter to it to see if there's any power left in it, and guess what?? There's no auxiliary battery! What I see here, is a small electrical device, next to the battery, and the plug that we unplugged in 2016, just dangling there. You folks think that I can simply plug it back in, with no ill effects??


(Man, why didn't I think of this, a week ago...............)

 

PLUG IT IN!!!!!!! You will be just fine. probably harder on the car not having it plugged in.

 

Thanks, Chris. I'm heading out to the garage right now..................

 

leadfoot4, what I find interesting is you mention that the car has a yellow ECO light that remains on when you disabled the ECO system. I now have a 2016 XJL and I do not have the ECO function in my car and I do not have a ECO light on the dash anywhere. I am wondering what the previous owner did to the car to make it that way. I may have to start looking around the car to see what was done. I am kinda pondering if the car does not have an upgraded tune to it that also eliminated the ECO function. Granted, not sure how I could/would prove that with just a code reader.

 

Chris, what model/engine do you have? Ours is a Portfolio, with the supercharged V-6 engine. (and now with the module plugged in, the green mode for the light flashed then went out, and the yellow light did not illuminate. I took it for a short ride, 8-10 miles, and it stayed out. In case you haven't seen this light, it resides in the lower, left hand corner of the instrument display.

 

leadfoot4, I now have the supercharged V6. So, same motor that you have. I can see where I can select ECO options inside the radio, but I have left them alone as I like the car how it is (does not go into ECO mode and I do not need to push a button every time getting in it). I hear all this talk about ECO mode, but I have not seen it in my car and I know I have been in numerous situations where it should have kicked in.

 

Chris, I wonder if you have either an "early" or "late" production 2016. Maybe there were running changes made during the model year. For the sake of discussion, the last 4 digits of our car's VIN is 3084.

 

OOPS, I hit submit twice...................

 

Just for the record, after plugging in the "Eco" plug, back into the device that's next to the battery, the "start-stop" function reactivated......and reminded my why we unplugged it in the first place. What a totally annoying invention that is!!!

 

Thanks for updating with the final details.

Do you have a pic of the plug that was removed? It's time for me to disconnect the system so I don't have to press the Eco button every time I get in the car.

 

Unfortunately, I don't, and we sold the car, yesterday, so I'm unable to get you a picture. However, the best that I can explain it is this....in the trunk, just in front of, and slightly to the left of the battery, is a vertical bracket that's attached to the trunk floor. Attached to this bracket, is a somewhat circular part, that has two sets of wires going to it. The wires to the "right" feed into a plug with a black colored housing. This is the one that gets disconnected.

Keep in mind, that it appears that different years and/or powertrain combinations may not have this device. As I previously thought, as a few have mentioned, that there's an auxiliary battery, that controls this function. Mine didn't have that battery, but I seem to recall reading that other models did. As I did mention, while "pulling the plug" deactivates the start/stop function, in my car it illuminated the yellow, "eco" light 100% of the time.

Good luck!


(BTW, we owned our '16 XJ-L for 8 years, and never knew of a button that would turn the start/stop off. Our 2020 F-Pace does have that button, though.....)

 

Here is a pic of my battery area. Did yours look like this one?



The ECO button I use is on the climate control panel. This is a pic of a 2016 panel from eBay. It looks like mine.

 

"lotus", yes, that's gizmo in the trunk, that our car had. The black plug was the one that we disconnected. Now you've got me thinking.....in the 8 years that we had the car, I don't ever recall seeing the "ECO" button on our dash. There might have been some sort of running change at some time in the 2016 model year, because if my dealer knew about the button, I'm sure they would have told me about it rather than showing me which plug to disconnect in the trunk, which is probably by law, a really "gray area".

 

WHAT A BLIND JACKASS I AM!!!

I just looked at the picture that you posted, "lotus", and that got me thinking. As I had previously mentioned, we sold our XJ to the area CarMax store, so I couldn't simply go to the garage and look at our car, to compare our dash control panel to the one in your picture. I got curious, and looked at CarMax's webpage, to see if they had our former car listed for sale. Sure enough, they did, and they posted a number of pictures, including a couple of the dashboard area.

Looking closely, don't I see the %^&&^% Eco button in place!!! 8 freaking years, and we never noticed it !!

 

You were better off disconnecting the wire anyway. Pressing the button every drive is a bit annoying.