Went for a drive after fixing my IAC valve and while on the highway my (O/D off) light started flashing... transmission did not go into safe mode or do anything different. It was still running smooth as silk. In about 5 minutes the light stopped flashing. When I got home I checked the fluid and it was a tad high (I overfilled a bit last fluid change) but nothing drastic. I drained about half a pint and got it to the perfect level. Went for another cruise for an hour and the light never came on again and the trans still ran great.

WTF? My scanner doesn't read transmission codes so should I worry about it and find a scanner that can in case it stored the code? Any ideas why it would do this?

 

Did you unhook the battery during or after reinstall of the IAC Valve?

Could have been just a relearning glitch in the computer

 

No, I usually do disconnect the battery whenever I mess with electrical connections but I didnt bother this time.