I have 2014 F-type base with 5K miles. This has happened twice - switched off Eco start/stop button while at a stop light. Drive light starts flashing and the car acts like it is in neutral - pressing accelerator races engine but car goes nowhere. First time it took around 25 seconds for the situation to clear and drive to engage normally but I don't know what I did or didn't do for this to fix. The second time I manually selected neutral then put it back in drive and then the drive light stopped flashing and the car drove normally. The owner's manual refers to the flashing light as drive being selected but not accepted. Accepted? What is that supposed to mean - the transmission gets to decide if it likes my choices? Dealer looked over car could find nothing wrong , no error codes etc. Suggested I just avoid using the Eco start/stop system, which I can do but I'd really like to know if anyone else has had this problem and/or has a fix. Thanks!

 

Could be related to this:

https://www.cars.com/articles/2013-1...1420682963160/

 

............happened to me twice. Then I took a mental note to self: Don't disable ECO when ECO stopped. It does act like a software/transmission/ECO status glitch.

Desert Hiker

 

I have a 2014 too. Disconnect the small battery in trunk - and the ECO thing is disabled permanently. I always found myself cursing a bit while disabling on the switch whenever it did the ECO stop on me, so I disabled permanently more than a year ago; no side-effects at all - recommended for anyone reaching for the switch every time the engine turns off at a stop

 

Is there any data on how much gas eco mode actually saves?

 

I guess it depends how much time you spend stopped. With my driving in the suburbs, back roads, and turnpike it would be next to nothing.

 

I've seen numbers published citing 2-3% savings on the EPA gas mileage protocol.

When I'm stuck in Washington, DC gridlock, which is pretty much every weekday, I leave eco-mode on all the time. I've learned to like it, and it's performed flawlessly for me.

 

When I was in Bethesda, the combination of DC traffic and the heavy clutch on my e-Type was the first time I decided an automatic isn't all bad.

 

Edit: never mind, never learned the alphabet properly

 

Can somebody tell me where the small battery is? All I've seen is the main battery under the rear floor.

 

On the right side at the rear of the trunk. Follow the red and black cables to that area. It is under a bracket and much smaller than the main battery.

 

Found a picture. Top right of picture below under bracket and red cables.

 

Any idea what the second battery is for?

 

It is for the ECO Start/Stop at least I haven't seen any other side-effects of disconnecting it.

I am guessing that the car's electronics get juice from the 2nd battery while in ECO Stop - and if that 2nd battery gets "low" then the car starts to get the alternator going again.

 

Thanks for pointing out how to disable this "feature".

 

Has anyone else noticed that their ECO does not turn the engine off when outside temp is below freezing? Might be a change in programming after they eliminated the 2nd battery. Please weigh in with your model year.

 

I believe ECO will not stop the engine if the algorithm determines that inside cabin temperature cannot be maintained if the engine stops. ECO never shut off my engine when I took it out on a 95 degree day, top down either.