RS246.com Forum :: The World's #1 Audi R, S and RS Enthusiast Community

Hi guys, am after some advice before I take a trip to the dealers. My rs4 has been parked for months and when I started it fired up straight away but with warning lights tpsm,brake malfunction, suspension fault etc. I went and bought a brand new battery. It fired up and warning lights were still there. As soon as I tried to drive away pdc started clicking and car shut off completely.
Now I can’t lock/unlock the doors, insert key no lights on dash but interior light comes on and window operates. No power boot.Any ideas what it can be??

Have you checked all your fuses?
Notice any rat droppings around the car?
Have you got VCDS?
If you haven't got VCDS, post a rough location of where you are and may be someone on here will be kind enough to come and scan your car.

Most important of all - FON.

Not checked all fuses but I’ll do that. Not noticed any rat droppings anywhere. Yeh unfortunately I don’t have VCDS. I am located near Preston

There's a VCDS forum section on here, check your fuses first, then stick a post up in that section seeing if anyone can help out.

Thanks mate I’ll do that.

There is enough information on here about fault lights (especially suspension fault lights) due to a low battery voltage. The car shuts down some systems if it detects a low battery on start up, one being the suspension system, throwing up the dash warning.
The advise is that replacement battery (which has be an AGM battery) should be programmed to the car using the QR code on the replacement, otherwise some electrical systems may not function correctly so I understand. I only know this from the information I was given when I had to replace my battery about 18 months ago.
Some have said it isn't necessary and have apparantly got away with fitting new a battery without reprogramming and had no problems, but when I enquired, that is the advise from Audi and also from independant battery suppliers. Motor factors may probably suggest to the contrary, as they won't be in a position to do it, but assuming that you have fitted an AGM battery, your problem could be down to not having the battery programmed to the car.
The recommendation is there for a reason, I would suggest.

Thanks mate I appreciate the input on programming the battery but at this particular moment car won’t even come on or can’t even lock the doors from the key fob. I’ve checked all fuses and had battery tested and all good. It’s like it doesn’t recognise the key.

Have you got battery voltage at the fuses?

Yep getting battery voltage at the fuses. Not checked relays where Ecu is

Replaced my battery couple of months ago, was told by a mechanic friend of mine, don’t need an agm battery as my car doesn’t have stop/start, so no need to waste extra money. Not coded it to car, just changed it and off I went!!

Is the battery in the key new? Worth changing

Not tried that yet but I’ll give that a go

Changed key fob battery, still nothing

Does anyone know any good mobile electrian, northwest area?

Does it recognise the key when you push it into the dash?