To troubleshoot a vehicle that doesn't start, begin by checking the fuel levels and the battery. If the fuel levels and battery charge are normal, take the car out of park, put it in neutral and try to start it. If the problem persists, check the dash lights to determine whether the security light is illuminated, or reset the vehicle's anti-theft system. Examine the "check engine" light with the key turned to the "on" position.
If the battery is dead, examine the battery for corrosion or loose cables. Clean and tighten the cables if necessary, or charge the battery with a charger if the cables are working properly. Replace the battery if it doesn't charge when connected to an appropriate charger.
Re-program the key if the security light is illuminated, or try to start the vehicle with the spare key. If the security light persists, consult the dealership for assistance. Consult the owner's manual for information on resetting the anti-theft device, or consult a mechanic for assistance.
To determine whether another type of problem is present, turn the key to the "on" position, and examine the "check engine" light. If the "check engine" light doesn't illuminate, and the battery is charged, consult a mechanic to find the cause of the problem.