- 99% of the problem is the battery. 1% can be starter/spark plug. ! d& ?* n9 M7 d: B% }- if it's automatic transmission, check to see if the gear is set in park position. if it's in drive or reverse, you cannot start your vehicle. : x7 U) Y8 O& ~- make sure there's gas left in the tank + D4 y" ^2 C4 \; g* k9 p- depand on how old your car is, it may have a computer built in to control fuel injection. if the computer breaks, you won't be able to start the car either.