G35X Service Engine Soon Light - Torque Converter

I have a new G35X. With only 2200 miles on the clock there was a slight shudder in the transmission and the yellow service engine soon light came on. The car was ver slugish off a standing start. After the car was restarted, it seemed fine again. Took it straight to the dealer and they suggested a computer glitch, swithced the light off and gave me the car back.

At 2800 miles same thing. Dealer now has the car. Any ideas or information out there?

Thanks
ARJ