Q: Jetta not starting.

There are quite a few things that can cause a cranking no start condition on a Jetta. Some common issues are faulty crankshaft sensors and faulty ignition coil. Starting with the basics generally yields the best results. Listen for fuel pump operation while cranking vehicle. No fuel pump can indicate a faulty relay, fuel pump or crankshaft sensor. If the fuel pump is operating as soon as the engine cranks, the ignition system needs to be checked. This vehicle is OBD2 so reading any faults stored in the engine computer can lead diagnosis in the right direction. Enlist the help of a mechanic, like one from YourMechanic, who has the training and test equipment to help locate the cause of the no start issue.