hey guys i just rebuild my tranny twice in about two weeks. she started acting funny so i rebuilt it. Then on my way home from a trip she blew the front seal and threw up all the fluid, rebuild number two. Now i picked it up from the shop and the TCC doesnt not lock up. It throws a p1728 code. I replace the small harness coming from the solenoid pack to no avail. I traced the TCC wire to the closest place i can get to the fuse box we have good continuity. checked fuses everything good. i saw some threads about a TCC switch but i just want mine to work like it is supposed to. ANY i mean ANY info would be appreciated guys.
I don't have a wiring diagram and that would be helpful.
You need to see if the TCC solenoid wire is going to ground when it should lock. If it isn't going to ground then the PCM isn't commanding it to lock. That could be a PCM or a sensor issue. You will need a scan tool to look at data to see what the sensors are telling the PCM.
If it is commanding the lock and it doesn't lock the problem could be a bad solenoid, a stuck valve, a bad torque converter, or a bad seal on the input shaft.
Mark Former Ford Automatic Transmission Engineer
“The good thing about science is that it's true whether or not you believe in it.” ― Neil deGrasse Tyson
I'm having the same problem I run a snap on scanner on it and everything is shifting right and the pcm is telling it to lock up but its not think its the torque converter?
Not likely. I think you have a better chance of the front pump being the problem. Like a sticky valve or
Stick a volt meter on the TCC wire and make sure the PCM grounds out the circuit before you drop it. Make sure you stick the jumper wire as close to the solenoid pig tail as possible.
Have you checked the wiring harness to the solenoid packs? There were a few wires that didn't look too good on mine.