Hi, today my 2006 g35 coupe AMT started up fine in the morning, started up fine a couple more times. But then it began revving up slightly with no input or very light input. As I was driving through a parking lot, giving it 2% throttle and releasing would cause the car to gently accelerate with no input. I parked turned the car off, inspected the engine and now it doesn't turn over. It cranks, it's getting power, but my radar detector is reading low voltage. Anyone know what the issue might be?

 

Is it throwing any codes?