Changed solenoid. Truck shifting hard again with check engine light

Question

P0218 code was shown when mechanic checked.  Changed solenoid.  Truck ran fine for few days then hard shifting again with check engine light now.

Answer 1

P0218 Transmission high temperature operation activated

The cooling system needs to be checked, proper cooling from the radiator . If this vehicle has a transmission cooler filter change it. this would in the cooling of the transmission