05 Corolla Transmission issue, solenoids?

The issue: Car will not go into gear after the transmission heats up, was throwing transmission solenoid B(or 2) code. This is the way I purchased the car.
I went ahead and drained the fluid and cleaned the transmission filter( oil looked original to the car, as in 200k used). I changed all 3 transmission solenoids to OEM Denso. Bought them from a low mileage 2007 Corolla for $30 for all 3, absolute deal.

Installed them, transmission worked GREEEAT. Like new. Two weeks later..... Problem is back again after running a lot of errands today. What could the problem be? Transmission oil cooler? I am considering buying a new transmission just to be done with it, but was wondering if anyone had another idea what it could be.

Thanks in advance!


New Member
Check if the transmission fluid is cooling down correctly, there is a radiatior in front that cools down the oil, if that doesnt work well it means that transmission is done doing its job just get a new one.