- 99% of the problem is the battery. 1% can be starter/spark plug. ' R0 M$ t; _; Z" G6 D L- 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. + t7 q3 d/ U# f9 ^- make sure there's gas left in the tank * p$ B8 Y- H( c6 ]9 G; M% a- 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.