final drive cover on the rear of the transmission or by vacuum extraction through the speed sensor hole. Vacuum extraction is the more attractive option since a paper gasket seals the steel cover and access is very difficult. Filling is through the speed sensor hole. Differential oil capacity is about 1 liter. An acceptable differential oil is Redline synthetic MT-90 75W90 gear oil or any synthetic 75W90 GL4 gear oil. Be very careful not to introduce sand or dust into the differential, as the differential has no way to filter its oil. Transmission controller The shifting of this transmission is controlled by the Transmission Control Module, or TCM. There are three shift modes that the transmission can be set to which alters the shift points as well as the speed of the shifts (amount of transmission slip between shifts). Factory Mode, Economy/Touring Mode and Sport Mode. Economy mode endeavors to keep the engine revolutions lower to save fuel, while Sport mode allows the engine to rev higher before shifts, as well as shift faster with a sacrifice to economy. Changing these modes require transmission programming through a factory scan tool. This computer uses "fuzzy logic" to learn the driving habits of the driver in order to set its specific shift points. If two or more drivers with different driving styles have been driving the car, the TCM may become "confused" and start acting goofy. Such goofy behavior may manifest in hard shifting, slipping, trouble getting in gear at idle, etc. A quick fix is to reset the "fuzzy logic" by performing the following: Sitting in the driver's seat turn the ignition on without starting the car. Immediately put the accelerator to the floor. Count to five seconds. Release the pedal. Turn the key off then immediately start the engine. If your problem is from a confused TCM, this will solve the problem. This will not reset trouble codes in the computer. That must be done with the proper OBDII scan tool such as the VAG 5052, VAG COM tool at the VW dealer. The transmission computer is located under the back seat on Volkswagen Golf Mk3 /Jetta/Passat models, under the right side dashboard cover on Volkswagen New Beetle models, and in the wiper area plenum on other Volkswagen Golf Mk4/Jetta models. Predecessors Before the 01M transmission, VW used the 096 four-speed for Mk3 Golf/Jetta cars from 1992-1994. These cars will