P0778 transmission problem!

[Shehzad102]

Hey everyone,

So my 03 LX470 has developed a strange issue. Symptoms are that it won't go into 5th gear and downshifting from 2nd to 1st is very rough. I only have one code and it is P0778.

Through digging around on the forum I thought it might have been the ECU but turns out there is nothing wrong with it. I have also checked the wiring harness and have not found any issues with that either.

I see that some other people have had the same issue with there 100 series as well and wanted to see if anyone had come to a solution? Any feedback would be appreciated!

 

[2001LC]

First thing I do with any transmission issues. Is look if level correct. Second; has any fluid ever been added to it and what that fluid was/is. Third; I flush all 12 qts out, with proper fluid. Which in the 03LX is Toy-IV ATF.