Can you turn off the SES light without a scanner (i.e. snap-on or similar)?...
Mechanic friend says you can't do it without a diagnostic tool like a snap-on scanner. Any other way to do it?...

 

Won't disconnecting power to the PCM for 15 minutes reset everything?

 

Pulling the power to the PCM (pull the "PCM BAT" fuse for 30 seconds), will clear the volatile memory, meaning the DTC codes, long term fuel trims and learned idle position. If the SES was on because there was an active DTC code, clearing the PCM will not accomplish anything, as far as the SES light is concerned. If the problem is no longer "active" the PCM should turn the light off. If the problem is still there, the light will just keep coming back on.

 

I guess there is really no way to bypass a specific SES generated code.... Every couple of weeks the speed sensor picks up a non-specific slip in the tranny/drivetrain. It doesn't affect the performance or reliability of the car, just a pita having the SES light after a few weeks with it being off. The Snap-On isolated the torque converter and every gear separately under load and no fault was found. I just don't like bothering the mechanic every time the light comes on. He doesn't mind turning it off for me, but he spends half an hour troubleshooting it for the same thing. He says there is nothing wrong that he can find. I'll try pulling the PCM BATT fuse like you indicated to give him a break...
Thanks for the help...