After being on the highway 40-50 miles going between 80-90mph, the SES came on. Not flashing but solid. I pulled over, and pulled the PCM for 30 seconds or so and started it and it was still on. I'm getting it scanned Monday I belive unless my buddy can do it this afternoon. I know it can be a million things, but in your experience what could it be. The car has been running fine, and was running fine previous to the light comming on, and was running fine even thought the light was on.

Last week my water pump went, and I'm sure it got the opti wet, but the car doesn't stumble at all, and runs just fine, could that be it?

 

If you reset the pcm, your code will normally be erased. Your scan may show nothing.