MERCEDES Auxiliary Battery Replacement W166 ML/GLE 350 later variant not under front seats or trunk

A 'How to' fix mercedes auxiliary battery malfuncion warning and quick location description of where you can find the auxiliary battery on Mercedes GLE models or models with chassis W166. My aim will be to save you £££'s by showing you ways you can fix your automotive problems at home instead of taking it in to the repair shop. Mercedes-Benz models are well-known for their impressive technology list, and many of their modern cars have two batteries – the main battery and an auxiliary battery. If this auxiliary battery develops a malfunction, it will show up as an error message on the dashboard. The warning will be generic, but should feature a small battery symbol. You will know that it's the secondary battery that is at fault, because the car will still turn on and nearly all functions will still work. The auxiliary battery should not affect the car’s mechanical functions. If you are unsure, you should be able to diagnose the fault with an OBD fault code reader.