what does this code mean P1494?

I have a 2000 Chrysler Concorde LXI and the check engine light is on. I took it to auto zone to have them put it on the diagnostic and the OEM # was P1494. The definition says: evap leak detection pump pressure switch condition. Explanation----- ECM detected the leak detection pump switch did not change after the solenoid was energized. Problem cause--- 1. Leak detection pump defective 2. Open or shorted circuit condition 3. Solenoid defective. If someone could explain this to me I would greatly appreciate it. The car actually drives fine i just want to get whatever it is I need to get fix before something major happens. Thanks