Digimat
Digimat is the trade name of a series of digital transmission control units for controlling the first electrohydraulically controlled 4-speed automatic transmission from Volkswagen . Digimat has been used in various Volkswagen models since 1989 in order to achieve the "correct" gear and smooth gear changes with minimal consumption in vehicles with automatic transmissions.
Development and manufacturing
The hardware and software of the Digimat is a purely in-house development by Volkswagen. Production is carried out by the suppliers Hella and Siemens .
commitment
The Digimat controlled the automatic transmission in the vehicles VW Golf (up to Golf 4), Golf Ecomatic with automatic swing mode , Jetta , Corrado , Transporter , Sharan , Passat , New Beetle , 3L-Lupo , Seat , Škoda , some Audi models, in the Fiat Tipo and Tempra , in the Lancia Dedra and in the Mercedes V-Class .
technology
The Digimat uses an 8/16 bit MC68HC11 microcontroller from Freescale (formerly Motorola ) with external flash memory.
Aisle determination
The maps are programmed for specific types. Since version 2.1 (1995), driver type recognition with the help of fuzzy logic and driving performance recognition have been included, so that the correct gear is always determined depending on driver behavior, on the mountain, when towing a trailer and with reduced engine power at altitude. The transmission hydraulics are controlled via electromagnetic actuators.
Sensors
- Speed sensors (inductive)
- Transmission oil temperature sensor
- Selector lever switch
Actuators
- Switching valves for clutch control
- Modulation valves for pressure control (current-pressure converter)
- Shift lock magnet (blocking of the selector lever)
- Starter release
Networking
Digimat is networked with other control units (engine, brake, station wagon, air conditioning) via the CAN bus , contains extensive diagnoses, fault memories and also meets the strict USA OBD requirements.