'96 Cent. tcc prob.

OD trans. above 45 mph does not want to release (unlock) tcc. Shudders, bucks etc. Below 45 will release smoothly. Was just remanned.
Any ideas?
Has Quad 4 eng.

The ECM controls the TCC solenoid. When the engine is below a certain speed or above a certain speed it denergizes or energizes accordingly. The actual lock is supposed to occur when you reach a set speed. It should unlock when you slow down. If it does not unlock, it will shutter to a stop and stall the engine when you stop. it appears that the solenoid is not operating properly and should be checked. You might try unplugging the TCC at the tranny and see how it operates till you get it fixed. The worst that can happen is you won't have OD and you'll get less mileage.