automatic transmisson A750F will not shift into 5th.

[Peder]

Hi!

i have a hilux 3L 2011 model, and i have a very odd problem.
when i have driven from 10 km to 40 km the transmission will not shift into 5th/ overdrive. the transmission is shifting very good all the time but then randomly will not shift into 5th. and it does not help to "force" it into 4th and back to D.

But if i stop and shut the car off for 10 seconds and start it again its fine and shift perfectly.

when the problem occurs i can hear the engine is reving like 100rpm and its trying to shift but cant. And there is no fault codes or engine light.

i have tryed to change the Egnine ECU, Transmission ECU and the hole transmisson without any sucsess. i have also tryed to follow the cables but cant find anything suspicious..

do any of you guys have any suggestion what to check out next?

( im sorry if the English is not on point, im Norwegian...)

[ptrl1600]

Don't quote me, BUT I think that the only difference between 4th and 5th gears are in the switch in the shifter. The shifter lever moves up and down to select the gears, but when it moves sideways eg 1st to 2nd and 4th to 5th, it simply activates a switch in the shifter. I would check to see if it selects 1st manually? If not the problem could be the switch in the shifter or the solenoid in the transmission that the switch energizes?

Just a thought?

[Smartchap1]

Hi, did you ever found a fix? hoping for feedback as I have exact same symptoms and no codes