Ranck:
The “Check Engine Light” & “Service Engine soon” serve the same function!!! They do not indicate the need for an oil change. I am aware that some vehicles have an on board system for oil change reminder but they do not iluminate the service engine soon. This light is a Malfunction Indicator Light (MIL) that warns of an emmision problem. It is not a maintanence required light.
For more info visit:
http://www.carcare.org/Emission_Control/check_engine_light.shtml
http://www.ncvecs.colostate.edu/ncvecs.docs/MILSheet.pdf
http://www.repairtrust.com/check.html
If you want more I can provide them.
~Michael