Volkswagen Passat 1988-1996: Integrated engine management system «SIMOS» (8-valve engine / Control system «Simos»)

KSUD «Simos» applied to engines «AGG» release 1995-96 and includes a subsystem for controlling distributed fuel injection and a subsystem for controlling the ignition timing. The principle of operation of the system is similar to that «Digifant». Placement of KSUD nodes «Simos» on the car is shown in Fig. 2-122. The fuel injection control subsystem includes the following main components: mass air flow meter. Exhaust Oxygen Sensor, Throttle Position Sensor, Idle Air Control, Controller, Fuel Pressure Regulator, Coolant Temperature and Intake Air Temperature Sensors, Fuel Pump and Fuel Filter. The controller, located behind the bulkhead in the middle, provides control of fuel injection and ignition timing based on information provided by the system's sensors. The submersible type fuel pump is installed in the fuel tank. The intake air temperature sensor is mounted on the air filter housing. The coolant temperature sensor is located on the coolant supply housing and cylinder head. Both sensors have a negative temperature coefficient. those. their resistance decreases with increasing temperature.

Pic. 2-122. Placement of EDMS elements «Simos» by car:
1 - solenoid valve for adsorber purge;
2 - air flow meter;
3 - connector for the oxygen content sensor in the exhaust gases;
4 - throttle body;
5 - controller;
6 - nozzle of the injection system;
7 - fuel pressure regulator;
8 - ignition coil;
9 - tachometer sensor;
10 - knock sensor connector;
11 - connector with a central output;
12 - crankshaft speed sensor;
13 — a socket of the gauge of frequency of rotation of a cranked shaft;
14 - ignition distributor;
15 - coolant temperature sensor;
16 - knock sensor;
17 - connection with «weight»;
18 - intake air temperature sensor;
19 - adsorber.

The mass air flow meter is mounted on the air filter housing.

The throttle body, located on the intake manifold, includes the throttle valve, idle air control and potentiometric throttle position sensor.

The idle switch is located on the throttle body. The idle speed controller consists of a stepper motor and a damper that regulates the idle speed of the engine by changing the amount of additional air supplied. A potentiometric position sensor mounted on the throttle body provides an engine load signal.

The adsorber is installed on the front right wheel cover. Canister purge solenoid valve installed in the same place. controlled by controller commands.

An exhaust oxygen sensor with an integrated electric heater is installed in the exhaust pipe before the catalytic converter. The sensor transmits to the controller a voltage signal proportional to the amount of oxygen in the exhaust gases when the sensor temperature reaches 300°C.

Details of the fuel injection control subsystem KSUD «Simos» are presented in fig. 2-123.

Pic. 2-123. Details of the fuel injection control subsystem KSUD «Simos»:
1 - air filter;
2 - controller;
3 - air flow meter;
4 - air duct;
5 - throttle body;
6 - inlet pipeline;
7 - gasket;
8 - coolant temperature sensor;
9 - crankshaft speed sensor;
10 - oxygen content sensor in exhaust gases;
11 - control valve of the crankcase ventilation system;
12 - intake air temperature sensor.

Integrated engine management system «SIMOS»

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