Napalm

if you drive the truck a while longer I wonder if it would reactivate. I don't recall when mine stopped but I want to say it was around 0C but that was for a short drive (less than 20 miles). I bet if you has a longer drive or just in general a longer commute it might come back on.

IE engine was at 98C but hadn't been there long enough. It might be looking for Engine at ___ for more than ____ minutes. Or there is an absolute OAT cutoff point. and maybe it's 0C or 32F

MNgopher

Was your truck parked outside for a decent period of time before this? Guessing the battery temp, which I believe is monitored, was too low. If you'd keep driving the truck for a while, that goes away. This happens in temps at or below freezing - I think the batteyr must be around 40 degrees or higher for the system to work.

KrS14

You guys are missing the main issue here:

Ford service says:
"Engine On due to Low Temperature" in the dash = Engine is on in order to increase the engine temperature to an acceptable level.

That has nothing to do with outside temp. It specifically says engine temperature.

If my coolant is at almost the boiling point of water, the engine is at operating temp.

KrS14

Maybe Ford is being stupidly vague with this one though. Maybe they REALLY mean, "Engine is on to MAINTAIN the current engine temperature at the acceptable level."

I guess that would make sense.

MNgopher

You did notice the link you provided was for a 2014 Ford Fusion, correct?

Have the same document for your year of F150?

I'm still guessing that the battery temp is the issue - and this is the message that comes up. I can tell you that is how my 2016 behaves anyways...

KrS14

I actually totally didn't notice that lol I'll try to find some information that doesn't suck, my bad lol

KrS14

So it looks like Ford got rid of the explanations for what will come up.

http://www.fordservicecontent.com/Fo...userMarket=USA
^^ Is the 2017 f150 equiv.

I'll take the battery temp explanation as it looks like we won't get a for sure answer. Too bad Ford can't say what they mean lol

Thanks guys!

MNgopher

No worries. I've been looking for the details myself (admittedly not looking hard, lol) and hadn't found it.

I know in my 2016, once the coolant temp hits about 130F/54C, the stop start system will engage, assuming everything else is met. So you are definitely right that at 98C it should be working assuming everything else is a go.

The battery temp is the only other one I could come up with that helps explain it.

Napalm

Well let me ask it this way - for people in the great white north - assuming all is happy with your car - does the start stop system work when the temp is down at 20F or -3C.

the ECU which is where start stop programing lives - is able to reads alot of things including having the battery condition which is more than just battery Vdc. So yes it might well recognize that the battery isn't to temp, it sees the engine oil temp, coolant temp, trans oil temp, IAT and OAT (intake and outside air temp). So the error message might be misleading but it could be that while the oil was up to temp and the coolant was up to temp the battery might not have been and so it disabled start stop.

Has your start stop reactivated since?

mikeinatlanta

Don't live up north but had freezing conditions a few days ago. Got this message when it was cold out and it went away after things warmed up. Not the truck, the air temp. Truck was fully up to temp.