This DSX Tuning conversion harness makes switching from a 6L80/6L90 to a 4L80 a breeze. The harness is entirely plug and play, and features a DSX Tuning 3D printed connector to facilitate easily plugging into the factory vehicle harness where the stock A6 connects.
The harness includes a pre-flashed T42 TCM that is configured to operate the 4L80 correctly without relays. The shift solenoids function normally, however the TCC will not have PWM ability (receives full pressure immediately). The input speed sensor will function correctly as well, and so will cruise control and the back up camera.
This harness DOES require a long shift shaft on the transmission to accommodate a PRNDL switch assembly (single connector version). Tap shift is not supported.