Technical Stop Start - Battery?

[GM27]

Fiat 500 (2011) - Stop start warning light is illuminated on dashboard and now the engine management light has come on. Plugged in fault finder and P1220 code came up. Is it possible that both issues are due to a faulty battery?

 

[jrkitching]

Fiat 500 (2011) - Stop start warning light is illuminated on dashboard and now the engine management light has come on. Plugged in fault finder and P1220 code came up. Is it possible that both issues are due to a faulty battery?

It's certainly possible; some would even say likely. That said, there are many faults which, when triggered, also disable the S/S system; failure of just about any lightbulb is enough to do it.

Conventional battery testing, particularly with cheaper battery testers, is all but useless; there have been countless posts from folks who've had S/S issues with batteries which tested perfectly, yet replacing the battery instantly fixed those issues. Indeed, I've said before that the best way to test a battery is to put it in a 500 and see if S/S still works!

Replacement isn't a guaranteed cure-all, and S/S batteries aren't exactly cheap (£100 or so if you shop around), but if you can't be sure yours is less than 3yrs old, it's a good place to start.

If you have access to a known good battery you can swap it with, that might give you more confidence that forking out for a new one will fix the problem.

 

[Ralf S.]

It's also worth leaving your battery to charge all night and then take the beast out for a spin. Even if the battery is getting on a bit and can't hold onto the highest level of charge, coming straight off the charger will have it temporarily (at least) full of beans.


Ralf S.