What does it mean when the check engine light comes on with no code

How do you know there is no code? Have you had it scanned?

ok, there was no code that came up in my car

Then it needs an OBDII scan with a scanning tool. Some auto parts houses will do it free. But before you buy anything, bring the code(s) back here and post them. Some of the guys that do the DTC scans know what they are doing. like putting the PID in for cooling system since that was the only thing that happened. But it may well be unrelated. Some of the guys..not so much. They might talk you in to buying parts you don't need, especially electrical parts that can't be returned