a problem like this is usually not a large one... bad battery... loose connection... battery cable.... diag can sometimes be a pain but try a few different things b/4 you panic and take it to the dealer and they charge you $400.00 for a bad battery... or a loose connection... i am in the rental and service business i was an equipment mechanic and a car mechanic for years believe me take your time im sure alot of people on here have alot of good advice for you