I have a 2005 Smart fortwo. Then engine light just came on. I am wondering what would cause this. My husband has checked the oil & prestone level and both are fine...HELP!!!

When the check engine light comes on its to tell you something is wrong,like a bad sensor or other emmsion controls, there are many reasons for light to come on like 50 to 75 diffrent things can make light come on, you will need to have the computer scanned for codes,when ever the light comes on the computer stores codes of why it was turned on, these codes will help in finding the problem, there are autopart stores that will scan it for free and give you the codes, if you get the codes i could help a little more, start with getting the codes, also as long as the light is not flashing your not causing any damage but should be checked. hope this helps.