ML 320 Voltage

[vagirl38]

A question for this forum. I have a 2002 Mercedes ML320. The last couple of days I have experienced transmission problems that has put the vehicle into the "limp home" mode. As I live in a very rural area I do not have a MB dealership closeby. The local tech said he retrieved low voltage codes and that I needed a new battery. He then called the nearest MB service center and they said that what was needed was a valve body and another part that was a very common problem with this vehicle.... to the tune of $1500. I'm thinking that a battery might be all that is needed but would like some input.