2003 Toyota Pickup 2003 Tacoma won't go in overdrive after

I changed the transmission filter and fluid in my 2003 Toyota Tacoma 2wd, with a 2.4L 4 cylinder. Now it will not go into overdrive. While I was changing the filter a tube that travels over the filter fell out , but I put it back in the way it came out. I checked the new fluid level after the engine warms up and I have set the parking brake and cycled the transmission through all of the gears (starting and ending in park). I have no idea what the problem might be. Any insight would be greatly appreciated.