Integrated engine management system «DIGIFANT» (VW Passat B4)

Cars with engines "RV" and "2E" are equipped with the integrated engine management system (ECMS) "Digifant" by Volkswagen. ECMS is designed to control fuel injection and ignition timing (ITA). Functionally, it consists of two subsystems: fuel injection control and IAA control. Both systems are interconnected and operate synchronously with the main engine operation cycle. The subsystem operation is synchronized by the controller using sensor signals. A single controller for both subsystems controls the actuators based on information from the sensors in accordance with the program stored in the memory, automatically optimizing the IAA, the amount and moment of fuel supply depending on the engine operating mode. If some sensors fail, the controller switches to a backup control program based on signals from the air flow meter, coolant temperature sensor and knock sensor. This allows you to continue driving the car, excluding engine failure. The design diagram of the ECMS "Digifant" is shown in Fig. 2-84.

Fig. 2-84. Structural diagram of the "Digifant" control system:
1 - fuel tank;
2 - fuel electric pump;
3 - fuel filter;
4 - distribution main;
5 — fuel pressure regulator;
6 — controller;
7 - injection nozzle;
8 — starting nozzle (engine "2E");
9 — idle air adjustment screw;
10 — throttle position sensor (engine "2E");
11 — idle switch (engine "RV");
12 — full load switch (engine "RV");
13 — throttle valve;
14 — air flow meter;
15 - knock sensor;
16 - coolant temperature sensor;
17 — ignition distributor with Hall sensor;
18 — electromagnetic valve for idle speed stabilization;
19 — battery;
20 - ignition switch;
21 — control relay.

(The information is presented on the website VWmanual.ru)

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The text has been checked: Kolesnikov Artem

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