this is caused by the sensor tripping in the light sensor to see what causes this you must diagnose it with a computer and see what fails in it.
You may think there is nothing wrong but there is. If the check engine light is on there will be codes stored in the ECM. Have the codes read. The codes will help you determine what the cause is.
If not installed properly check engine light will illuminate
Check
check
there could be a thousand different reasons. there is no way to tell or even guess with the iformation you have given.
in neutral while engine warm and running. be sure to have emergency braake on.
http://www.scribd.com/doc/6382741/Mitsubishi-Galant-2003-Systeme-de-Chauffage-Et-Climatisation- check section 50-40 AlexR
It will be an icon of an engine or it will just say Check Engine.
Check your coils on the sparkplugs
Mitsubishi gallant is both automatic and standard. You can check out some car classifieds on the net to see the different transmission.
You cannot reset a code. Take out your radio. Check the serial number on it and call Mitsubishi dealer. They will check a database and give you a code.
I'm not positive but, i don't think the '95 galant or other yrs. have a "pump relay switch". they do have a pressure regulator and a relief valve. i would check your local dodge or Mitsubishi dealer and ask them.