I being a master auto mechanic for 27+ yrs have taken on this issue w a recent customer. The corolla is a 2007 (12/06) w 90k on it. I checked the code - (p0741) was present. I drove car on a highway road test (9.4 miles) to check TCC lock up solenoid operation. All worked perfectly. Checked vin if ECU was a recall candidate; No, it's not. Checked fluid; on a white rag it left grayish color. (Trans fluid should be red.. as it wears, brownish it becomes not grayish-Brown.) Removed trans cooler lines and flushed out cooler till it was clean. Hooked up inlet line into a 5gallon jug of fresh trans fluid, while the outlet line into an empty 5 gallon hug. Started car on lift and ran car thru it's gears until fluid was cleared of grayish fluid. Reinstalled cooler hoses. Drove car again w a pressure gauge teed into cooler lines. Also used my Verus, watched TCC solenoid operation w a lab scope that I backprobed into the ECU too see if EcU is working properly. Drove this for a (9.4 mile ) on part highway & local roads. All was good. Rechecked fluid - clean. As this point, being fair to customer, I told him too PAY ONLY FOR FLUID used and get back to me after he puts 200 miles on it. If light comes on again, then I will take another approach. Customer was pleased beyond belief with all that time spent but only paying for fluid. If after 200 miles goes by without light reappearing, then I would charge him the labor ($265)... He agreed. I will keep everybody posted if light reappears.