Ok, so, bad news.. C3 friction is gone, so, a rebuild is needed. Quote for a rebuilt valve body, internals and torque converter : 3500€ inc labour :( Too much for me.
Its quite easy to find used post 2002 aw55-50sn transmissions, with warranty. My idea is to buy one of those +2002 gearboxes, install ...

No, never replaced anything, you are confusing probably with another user.. I circulate for about 1month, everything was fine, so I dont think thats the problem..

No, engine / trans are in place.

So, finally got the diagonostic:
437: TCM-002F Lock-up function. Slipping or not engaged

Print

Diagnostic trouble code information

D4301826

Condition

The automatic transmission checks that lock-up is not engaged or slips by comparing the rpm signal from the transmission speed (rpm ...

He's not familiar with the Win10 install, he only uses Win7. He's a very nice guy.
But yesterday I ordered a cheap Win7Pro laptop, as I'll need to use the Vida several times to do the adaptation, etc, in case I need to change the solenoids. I really hope is it solenoids, not a clutch or pressure ...

Nice Precopster, will do, thanks for the advice!

Hi Precopster,

I have the Dice, but I keep strugle to install the Vida with my Win10 laptop.. Will try again. The 3rd gear skipping only happened once, that problem is gone.. Now its the 4th and 5th gear failing to lock the torque converter properly..

Thanks!

Thanks Oragex.

Back then, connected to the ELM (after the problem was gone), and I got: P1618, and P0768.

NOW, I have another problem, see here:
https://youtu.be/Ck5h0K217Ok
While on 4th or 5th gear, the torque converter dont lock up, while coasting, and sometimes, while Im easy on the throttle ...

Thanks a lot to both of you.

Well, tried the car again, did the same thing when shifting from 2nd to 3th, no gear, jumps to 4th, but the "bang" was way lower this time.. Drove the car for about 5km on safety mode in 4th. Turned off and on again, and its perfect!!
Shifts are perfect with the new oil ...

Managed to find a AW55-50SN from a 2003 s60 D5. Is it compatible? (does mine needs replacement, or just solenoids / B4 cover?)