Transmission will not shift into third gear

Vehicle is driving normal at low speeds, but wont go into third gear. I have only one code P0733 saying the TCM isn't convinced with the current output speed and gear selected (third). I ran some trouble diagnostics with a nice scanner that had a service mode that allowed me to select the gears manually to test the transmission. I am able to command first and second with no issues. When I command third, the car stays in second, but the transmission registers that it has shifted in to third gear. Also, if I try to shift into fourth, it seems like it goes into first gear. Monitoring the current gear under normal operation has a similar result. Looking at the scanner, the vehicle shifts from first to second to third but in reality the vehicle only shifted from first to second. Any guidance would be appreciated.