You need to get yourself a tool to read the codes off the ECM. An inexpensive one if you have a notebook computer is the Twin Scan II from Daytona Sensors. I have the older version (Twin Scan 88) and it works great. Will let you read and reset the codes as required. See this site:
If your engine light stays on after you start the engine, then you have a current problem creating trouble code. If the light goes out, then comes back on for 8 seconds and goes out again, there is a historic code stored in the ECM that is not a current problem.
After about 50 starts, the historic code indication will not show up.
As far as trying to help with what it could be, there is no telling. You need the diagnostic tool.