Dave Millward

Hi guys, I bought a 2005 cls55 amg about a week ago and I've noticed when I start it first thing it comes up with a message on the dash, something about battery convenience functions disabled. After driving for a while a message comes up saying they are now active. I've replaced the aux battery but it' still doing it. I had it plugged into diagnostics and the aux battery flagged up. Any ideas? Could it be the main battery? I was lead to believe the convenience functions was controlled by the aux battery. Also my parking sensors don' work and that' coming up with the control module not sending power to the sensors. Anyone know where the box is located? Thanks Dave

PieRat

Aux features run off the main battery. The aux battery is a backup for if the main battery fails because your brakes are electrical.

Check your alternator by putting into key position 2 (stage before starting) and triple tap the odometer reset button. This shows alternator output in volts. It should be high like 13.8+. If you cant get it to show google how to put your car in dyno mode and stop when voltage shows.

Otherwise your battery is stuffed IMO.

PieRat

My alternator went out at ~100k km and died over a week or two..

Dave Millward

hi ya, thanks for the reply. I tried what you said and even googled dyno reset and did exactly what was said and nothing happens. Or am I missing something? Tried ignition in position 1 and 2 but no joy

thanks Dave

PieRat

Ill try it myself i think you need to ensure outside temp is on display. Ill let you know

Dave Millward

thanks buddy. On the screen it says nav off as the head unit is off, then bellow that I have I presume outside temp and then bellow that the odemeter reading.

PieRat

Yeah sorry looks like position 1 spam 3 times

PieRat

With lights and aircon on i get 13.5v