Transmission Issues - Need Advice

[JackDW]

First, 2003 Ranger Edge. 4x4 with 4.0 V6. Should have the 5R55E transmission (Automatic).

Daughter was trying to be "nice" to her Ranger and when through a car wash and included the under body wash. Upon leaving the car wash, the transmission started acting up. Shifted badly, check engine light and after a few miles the O/D start flashing. It sat a few weeks (to dry out) and no improvement. I pulled the code (a P720 I think) saying the a faulty Output Speed Sensor. Truck has no reverse and will not move forward in drive. Runs ok in 1st and second and will shift. If driven enough, it will eventually shift to the upper gears and then shift up and down correctly until you stop and cut it off. But, in no cases does reverse come back.

This past weekend I changed the Output Speed Sensor and not difference. Changed the fluid (pan only) and filter and no difference. I cleared the code and at this point, it has not come back but it hasn't been driven other that around the driveway. FYI, the inside of the pan was extremely clean. It may have been the cleanest tranny pan I will ever changed. Fluid was last change about 100k ago.

I keep reading in 2001 that the Transmission was changed to include an Input Speed Sensor. I picked one up at Autozone but can't find where it goes. Everything seems to indicate it is near the front of the transmission on the same side as the output.

What is everyone's thought? I can't envision it transmission would just go bad like that with no other symptoms. I really hate to yank that thing out if it is a sensor. But I may not have any other options.

Thanks for you thought and recommendations.

 

[Dirtman]

Pull off the connections to the main transmission harness, and the digital range sensor. Clean them, dry them and put them back. Then reset the computer. If you get water in either connection or in the range sensor itself you can get all sorts of insane codes and symptoms. Even after drying out you could have corrosion so its a good place to start.

 

[Transman304]

Unplug the main case harness and leave it unplugged and see if it has reverse. If it’s an electrical issue you will have reverse with it unplugged. These transmissions will have reverse and 3rd gear with no power to them.
Brad