Hi guys, 

 

My 2009 A3 2.0 diesel has an intermittent problem with the acceleration. When you try to accelerate it looses the abillity to do so as it normally does (seems like the turbo doesn’t kick in) and revs really slowly. Sometimes If I switch the ignition on and off everything works fine (doesn’t work always). Also no warning lights have come on. I took it to mechanics/technicians plugged it into a computer and no error codes came up. 

 

Please help me guys as nobody is willing to fix it because of the absence of warning lights and error codes.

I had those symptoms a few years ago on mine, together with loss of cruise control and loss of air conditioning. Turning off the engine for half an hour restored normal operation. The problem was caused by a defective battery, so fitting a new battery solved all the problems entirely.

I am not saying that is definitely what is wrong with yours, but it has become apparent to me since then that defective batteries can cause all sorts of strange electronic faults that do not show up on code readers, a fact confirmed by the mechanic who rectified mine. What makes it harder to diagnose is that a simple voltage test of the battery will not show anything untoward; it needs a deep discharge test, which most owners do not have the equipment for, to reveal the fault.

If you can not find any other fault and if your battery is more than four years old I suggest you get a new one, not a secondhand one. It will have to be coded to the car by the installer.