https://www.nissan-techinfo.com/infi...RefNo=ITB07030
IF YOU CONFIRM The vehicle has a shudder when the transmission is at operating temperature and the torque converter is: Engaging lock-up in 5th gear (light acceleration at 40 mph) and/or releasing the lock-up in 5th gear (coasting at about 40 mph). ACTION Replace the transmission valve body (control valve assembly). See this bulletin for further detail.

 

This is for the 06 sedan only.

 

I tried to use this for my 07 sedan, I was shut down.

On the plus side, the Cruise control ECU reflash fixed my 40mph shudder. I was surprised I had the same exact symptoms as this bulletin and a tune fixed it.

 

It must change the tq converter lock up parameters because mine definitely changed. Before (part of the problem) if I let off the gas, the converter would stay locked sometimes all the way down to 32 mph.

Now, it locks and unlocks closer to 40 mph.