Mackdawg281

I have an error messsge 'battery not charged' showing on the dash in a 2012 s550. I had the battery and alternator tested. All is good. The car starts fine. I am wondering if there is an auxiliary battery that needs replacing and what does this battery control. Sometimes the push to start won't star the vehicle and the clock resets. I use the key and it starts fine. It is service time so I will be taking the car to get serviced at an Indy shop. Just wanted to know if this is a reset issue or if someone has had this happen before

alexanderfoti

The aux battery controls the gearbox when the main battery is dead.

If your clock resets on start sometimes then your battery is likely dying.