- 99% of the problem is the battery. 1% can be starter/spark plug. & o% ?8 X. ~6 ^% H" J% }1 O- 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. ( B9 X- m$ [3 y0 R. Y- make sure there's gas left in the tank 3 h/ z/ ]. k* b3 d5 Z K s+ O- 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.