I have a 2006 V8 XC90 and it appears that the torque converter clutch is stuck on. The vehicle shudders and the engine knocks while stopped in R or D. It sounds fine in P and N. Trans fluid is only a few months old and already smoked.

Can anyone provide a suggestion on how to proceed? I have extensive experience with engines and engine software, but transmissions not so much.

Thanks.

 

How about this to get things started.

Where is the TCC solenoid?

Is the TCC engaged when the solenoid is powered? Or unpowered?

I want to bypass the control unit and see if the TCC disengages while stopped in Drive/Reverse and idling.

Thanks!