The vehicle used to produce this article is a 2011 VW Tiguan 2.0 TDI fitted with a seven-speed DSG. The code on the gearbox is OBH. The engine code is CFFB. The vehicle has covered 59,000 miles and has had one change of DSG fluid and filter about 30,000 miles ago. The DSG gearbox is common to many vehicles in the VW, SEAT and Skoda ranges.
In simple terms, there are two separate sets of gears and two clutches. It has a dedicated ECU which processes road speed, engine torque and RPM together with many other parameters such as throttle and brake pedal position, coolant and oil temperatures. It is processing the angulation of the vehicle in forward and side-to-side motion, steering angle inputs and the rate of change. The ECU then defines which gear is best suited to the parameters prevailing at that time and engages the next appropriate gear and clutch set, having also matched the engine revs to the gear and road speed. A ‘Mechatronics’ electric and hydraulic unit actuates the gear changes and clutch packs. The resulting gear changes are extremely rapid and smooth.
