P0770 CEL Hell on Earth

I had my 4runner 2x4 transmission rebuilt, and now its doing the P0770 trans error code thing. The valve body was replaced, the ECU was replaced, makes no difference - the code comes up randomly on the freeway usually when going up or down a hill. The car drives perfectly, can detect no erratic shift behavior. The rebuilder has NEVER seen this kind of weirdness, he now wants to replace the TC does this make sense going CRAZY ALREADY WITH THIS...........!!!!! Needless to say if I cannot get this ghost out of the machine I will have to burn the car.

Reply 1 : P0770 CEL Hell on Earth

I believe the only codes that can be thrown by the transmission come from the solenoids. There are 3 attached to the valvebody. Did they replace these when they rebuilt the trans?

Reply 2 : P0770 CEL Hell on Earth

Yes multiple times.

Reply 3 : P0770 CEL Hell on Earth

TORQUE CONVERTER BAD

Reply 4 : P0770 CEL Hell on Earth

So the TC was bad but it drove fine and shifted fine??

Reply 5 : P0770 CEL Hell on Earth

YES apparently....very strange....subtle clutch problem.....

SO FAR, it has not thrown a code, we'll see.

NOW I find out all tranny rebuilds use...rebuilt torque converters

This seems ridiculous, those things get TORN UP!

how many times was mine rebuilt - who knows!

Next time I go OEM new, screw the cost.

Reply 6 : P0770 CEL Hell on Earth

CEL 770 came on again, nightmare time. When I am doing 60+ MPH just comes on. Not shift solenoid, not TC, not valve body........all replaced, nightmare.

Reply 7 : P0770 CEL Hell on Earth

There must be something wrong with the wiring between the trans/solenoids and the ECU. The computer must be getting a wrong signal and it's throwing the CEL. Maybe when they did the R&R of the trans they yanked some wires a little too hard or something..?

Reply 8 : P0770 CEL Hell on Earth

ECU replaced, transmission harness, you name it, done, absolutely drives flawlessly, then at like 60MPH when it is just rolling along, CLICK there goes the CEL. My transmission rebuilder has never seen this problem EVER.......................



BUT WHEN I FIND OUT WHAT IT IS, YOU'LL BE THE FIRST TO KNOW.

Reply 9 : P0770 CEL Hell on Earth

Lol, I can't wait!



Not sure if this would help diagnose it or not but, try clearing the code again and then keep the overdrive off and see if the CEL comes back on again.



The ECU was replaced but I'm thinking there's something wrong with the wiring between the ECU and the trans.



Really though I'm just guessing...

Reply 10 : P0770 CEL Hell on Earth

MattinLA,



If it is not wiring what else could it be???????? Intermittant wire contact/frayed or broken would be a suspect.

Reply 11 : P0770 CEL Hell on Earth

My tranny rebuilder has NEVER seen this. You'll all be the first to know WHAT THE HELL this is.