2011 Fabia Greenline II CR, 95K miles


I've seen a couple threads of people discussing why Auto start/stop stops working in their cars after a while. The conditions are met but they still don't work after a while. The general suggestion found on this forum is to replace the battery as it gets old.

 

I cannot see actual age of battery, but I get 12.##v with the car off, and 14.##v when on, suggesting alternator is working and battery health is ok. But I've had "Start/Stop Not Possible" message from the time I bought the car. I didn't care for it. And often pressed the button to turn it off as I'm still in testing phase of this car and observing other matters.

 

The car needed a blower resistor as I could only use the fan on 4, and as I have a misting/condnsation problem, I need to use the fan longer on lower setting (4 is just annoying. I don't like noise). So I got the replacement part, a generic resistor, and replaced that.

 

In order to do that you need to have the battery disconnected (so I lost my trip and MPG mesurement and whatnot but to hell with that).

 

I started the car when I was done with fitting the new resistor, and with the fan blowing smoothly on 1, took on a 5-mile round trip, and to my suprise, Auto Start/Stop just kicked in. I drove for over 2 miles with my jaw wide open and eyebrows as high as they can get.

 

I believe it had more to do with the car or ECU being "reset" due to battery disconnection for a while, which may be what people who change their batteries ultimately do: they disconnect the battery for a few minutes while it gets replaced. So is it really replacing an old healthy battery with a new one that is making the system kick back in, as was suggested here by someone, or is it merely disconnecting the battery, and reconnecting it a healthy energy source regardless of age.

 

I don't know if this will be a correct assessment, but it may help someone out there or help give a better perspective on this particular issue, which seems to be fairly common in this car model.

 

Best of luck.

Edited 24 December, 20214 yr by KingRoach

Using the blower at setting 4 draws a good deal of current; approx. 20 Amps. I once measured this and was surprised how much it really is. 

It may simply be that now you are able to use the lower speeds, you're putting less total average load on the electrical system, so the alternator is able to keep up?

 

See if the improved situation persists. 

Your ##'s need refining by the way.

12.0 is a pretty low battery reading, but 12.6 is pretty good.

14.0V is a bit low for an alternator output but 14.4V is nice and will charge much faster. 

Can't fully agree as the previous situation was the same with the blower on 4 as well as on 0. With the heater off. Etc. 

 

Regarding the readings, I agree, but I'd taken the readings a couple weeks ago and can't remember exactly what the decimals were, but I recall them being on the good end of the spectrum, if not very good.

 

 

See if the improved situation persists. That is the plan and I'll update if anything comes up.

Sorry for being away so long. I may have spoken too soon. The start-stop only worked the first time I took the car after that job. It went back to not working from the following time I took the car up until now.

May this thread die in piece and go on top of the useless thread pile.

Have you checked the DTCs in your car?

It is possible that some controller has flicked up an error code which was cleared when you disconnected the battery and it is now back in the memory.

I had run the OBD scanner quite a few times before that episode, and have been sure no codes were coming up at that point. The only strange thing the car is showing is a Light Bulb dashboard light, when every single light in the car works properly. Could be one of the lights has a worn filament, but as of now, every bulb works. No codes.

 

It could also be, as a possiblity, when reset, the system kicked in, ran its default settings until it had its fill studying the battery voltage and decided that's enough, no more start/stop for you.