Today I was driving and when my car got into 3rd gear it refused to shift back down to 2nd gear, it then dropped to 500rpms while I was going 50 mph, then after I came to a stop and tried to start back up my car shut off and I got a dead battery signal. What is wrong with my car that could cause this? and it is fine in 1st and 2nd gear, just when it gets to 3rd it will not downshift back. I think either the timing is off or my vacuum hose is broken, but im not sure