Start Stop and Touch Unlock/Lock not working - battery dead?

[Lazar96]

Hi all,

Picked up 09 A4 and having a few weird issues that I’m not sure about. I’ve checked all the settings but can’t find anything. 

im thinking it could be battery issue maybe? 

Stop Start comes up in cluster I think saying it’s disabled, but nothing actually happens. Car is warm and been driving for a while.

Advanced key touch to lock/unlock isn’t working at all. 

Thanks in advance! 

[Magnet]

Hello James,

Thanks for being in touch. 

You are right in questioning whether the battery could be the source of your issues. If this were mine, this is where my first port of call would be. 

The car is 11 years old, and it’s reasonable to expect that it has already had one replacement battery, so the make/quality/ efficiency of this battery would be of interest. Of course, there is a remote possibility that the current battery is the original, but this would be exceptional for a stop/ start vehicle. 

Could you let us know what make the battery is James? 

I would now be getting the battery (and alternator) efficiency check, irrespective of whether the car still starts OK. Stop/start systems are the first to be disabled as the battery’s efficiency drops. 

Perhaps you could come back to us.

Kind regards,

Gareth. 

[Lazar96]

Taken it to Kwik Fit today to take advantage of their free battery check and they said it’s fine...

 

weird 

[jl-c]

Try checking resistance from battery connectors to under bonnet. Only needs a few Ohms to cause a voltage drop, which will in turn behave like a battery fault.

[Magnet]

Jonathan raises a good point, and all battery, and major earth connections, must be first class. 

OK, Kwik Fit declare the battery to be serviceable - probably by performing a simple ‘voltage drop test’ , but as I mentioned, other parameters of the battery’s performance - e.g. cold cranking amps - may also come into the equation to evaluate whether it is up to consistently operating a stop/start system. 

Kind regards,

Gareth.