A starting system fault can have many causes. One common cause is a problem with the starter motor itself. Other possible causes include a problem with the starter solenoid, the battery, or the ignition switch.
If the starter motor is the problem, it may need to be replaced. If the problem is with the starter solenoid, it may need to be cleaned or replaced. If the battery is the problem, it may need to be recharged or replaced. If the ignition switch is the problem, it may need to be replaced.
In some cases, a starting system fault may be caused by a problem with the engine itself. This is less common, but it can happen if the engine is seized or has low compression.
If you're having trouble starting your car, it's best to take it to a mechanic to have it diagnosed. They will be able to tell you for sure what the problem is and how to fix it.