The TCU (Transmission Control Unit) defines the way how a transmission operates and reacts to driver inputs. From a driver perspective the operation looks very simple. You stomp on the throttle and the transmission starts to upshift the gears and downshifts them once you slow down the car. The complex task behind this, is that the transmission must pre-calculate constantly what the driver expects it to do next, as there is no formula to calculate technically correct Shift-Points.

This is a multi-variable situation, where many things have to be considered like uphill/downhill driving, current brake-pressure, torque reserve of the engine in the current state, current steering wheel angle (cornering), current wheel-slip (e.g. ice or snow driving), special operating modes of engine/transmission (e.g. Particulate Filter regeneration, cold-start, overheat protection mode etc.), data from the Navigation System (e.g. tight corner or incline ahead), current gradient of the throttle operation by the driver and many, many more.

Mapping starts exactly where the computers capacity ends, and that’s the fine line between "technically correct" and "perceived correct". All those "hard" data points now get layered by the engineer doing the mapping with a certain target group in mind.