Could a weak battery cause EPC and Start-Stop warnings?

[redart]

Hi,

My sister's 2016 1.2 TSI Blue Motion has started displaying a few warnings - orange EPC and 'Engine' lights (on continuous), and console "Error: start-stop system" (flashes up on each start).
Car runs ok but is down on top end power, so presumably in some sort of safe/limp mode.

I measured the battery (EFB type, possibly original from new) at 12.5V last week and then again today - 12.3V in colder temperatures (just above freezing).

Could a weak battery cause these symptoms?. If so, can I change it myself or will the new battery need coding to the ECM ? (I don't have VCDS).

Thanks in advance.

[CarbonChaos]

Ideally you need to read stored fault codes on all control units first and go from there,anything else is guess work.

Try to find some where who can read fault codes for you on all control units first.

[ciclo]

According to the measured voltages it should work without these problems, but as already mentioned, it is just a guess.

[iichel]

I would expect other errors before an EPC light. better read error codes like suggested earlier

[redart]

Thanks for the replies. Will book the car into my local garage for diagnostics and update you with the results.

[redart]

Well it took a while but finally got the car in to the local garage -- problem is a seized turbo actuator. This is a common problem apparently on low use engines of this type.

Garage is quoting £750 plus VAT for a new turbo unit, plus labour on top of that .

Have seen online people having some luck freeing up the actuator with a little persuasion and a lot of WD-40. Anyone on here had a similar problem and found a fix ?

TIA.