1999 F350 v10 2wd automatic. Truck has been acting crazy for more than 6 months now. Diagnostics machine indicated the PCM thinks the transmission is being manually shifted into 2nd gear when it is clearly not. Code was 0705 Transmission Range Sensor. I have replaced the range sensor, had the PCM rebuilt, and verified continuity in the wires between the range sensor and the PCM. None of the local mechanics seem to have a clue. Any input would be appreciated.

 

You have either a bad range sensor or a problem with the wiring between the PCM and range sensor. I bet it's the wiring.

Verifying the continuity is one step to determining if you have a wiring issue. Did you also check each wire for short to ground, short to power, and short to each other?

 

Looks like you were right about the wiring between the PCM and the range sensor. Local ford dealer was able to duplicate the problem by wiggling the wiring harness. Mechanic thinks it is a plug in connector under the hood on the front driver side wheel well. He said he doesn't think it is a connection problem at the PCM based on where he was moving the wires.

Question is what is the best method for fixing it? My thinking is to cut the wires after they exit the PCM plug and before they enter the plug on the TRS, then splice in new wires. Or is it necessary to replace the female wire connectors at the PCM plug and at the TRS plug with each new wire?

 

the problem is likely the potions that remain when you cut the wires out. see if you can replace the connecting ends .