There are those moments where you skipped coffee and you are running late for a very important meeting, and when you try to get into your car, your car lock is not responding to the keys. There are different possible reasons why your car key is not working. If you have a relatively modern car, you are less likely to experience this problem since your car can be accessed through key fobs and keyless remotes, less likely but it can still happen. Older cars that still use car keys to open its door would likely to encounter this problem. The best way to resolve and avoid the occurrence of the problem is to understand the cause of the problem. Let’s take a look at the eight probable reasons why your car key is not working anymore. 1. Damaged car lock. Sometimes the problem is on the car key but on car lock itself. This problem is common among the older car models that still use a key to unlock the car door. The probable cause is the wearing down of the lock. Older car mo