Originally Posted by escapefate
wouldnt low oil pressure trigger a CEL
I don't think we have a transmission fluid pressure sensor in our vehicles so you wouldn't get a SES light for that. There *is* a temperature sensor for it, but it doesn't trigger a SES light. That sensor only causes your "shift indicator light" (just the little circle with the gear you're in on your gauge cluster) to flash when the transmission fluid exceeds 115°C (238°F).
So like Stayer said, it's probably a combination of the oil not being quite warm enough/too warm combined with wear on the clutch packs. Automatic transmissions are very sensitive to small differences like these, after all.