How to diagnose and troubleshoot a failing starter motor in an Audi A2?

I've noticed that my Audi A2 is having trouble starting up lately and I suspect it may be due to a failing starter motor. Can anyone provide tips on how to diagnose and troubleshoot this issue?

First, check the connections to the starter motor for any loose or corroded wires. If that doesn't solve the issue, use a multimeter to test the voltage going into the starter. If it's lower than normal, it could be a faulty battery or alternator. If the voltage is fine, the starter motor itself may need to be replaced.

It's always a good idea to have a spare starter motor on hand in case of emergencies. You can often find them at a lower price secondhand, just make sure to test it before installing to ensure it's in good working condition.

Another common issue with Audi A2 starter motors is debris getting stuck in the gears. Try to clean out any debris that may be causing the motor to jam. If that doesn't work, the gears may be worn out and need to be replaced.