Q: The engine EPC lights came on suddenly when I was driving.

Hi there. The EPC light and check engine light are coming on for there is something that is not functioning correctly on your engine. Either get a digital data scanner to scan the codes stored in your computer or have someone that has a scanner scan the codes that are stored in your computer. This will give you a starting place for diagnostics on your vehicle. These lights come on when a sensor has picked up an error or unusual operation of the part that the sensor is checking. If you need further assistance with determining why the EPC light and check engine light are on, then seek out a professional, such as one from Your Mechanic, to help you.