Integrated engine management system «MONO-MOTRONIC» (VW Passat B4)

Since January 1993, the "RP" and "ABS" engines have been equipped with an integrated engine management system (EEMS) "Mono-Motronic" bosch in combination with an exhaust gas afterburning system consisting of a catalytic converter and an oxygen sensor. The KSUD includes a fuel injection control subsystem and an ignition advance angle control subsystem. Both subsystems are controlled by a single controller, which optimizes the ignition timing according to a preset program, as well as the amount and timing of fuel injection depending on engine operating modes. The controller is a specialized microcomputer.

Applied in the KSUD "Mono-Motronic" the fuel injection control subsystem is a modified central fuel injection system "Mono-Jetronic" by Bosch. Some changes affected the design of the central injection unit (Fig. 2-74), in particular, the throttle damper was eliminated. In addition, the injector does not have a ballast resistor. and the fuel pressure regulator is made integral with the central injection unit. The throttle opening is adjusted at the manufacturer and is not subject to change during operation.



Fuel injection control subsystem devices different from the units of the Mopo-Jetronic system "Mono-Molronic" are described below.



Knecht brand air filter with a filter element replacement interval of every 60,000 km. Central injection unit of the brand and type Bosch 0 261 200 714. The idle speed controller has a built-in throttle switch that sends a signal to the KSUD controller that the throttle valve is in the idle position. The fuel pump has a capacity of 30% greater (at 12V voltage). The Bosch controller, catalog number 8AO 907 311 L, determines the optimal injector opening time and ignition advance angle based on the engine operating mode based on the information received from the system sensors. It is installed in the right front part of the car, under the instrument panel.

When the engine is running, the controller switches on the electromagnetic valve for purging the adsorber for a certain time. At the same time, outside air enters the adsorber, is saturated with gasoline vapors and enters the throttle space of the fuel injection unit.

The exhaust gas oxygen content sensor is installed in the muffler intake pipe and serves to send a signal about the oxygen concentration in the exhaust gases to the controller. The sensor supply voltage is 12 V.

The ignition timing control subsystem is controlled by the same controller as the fuel injection control subsystem and provides software control of the ignition timing based on signals from sensors.

The main components of the ignition advance angle control subsystem are: a controller, a Tele-funken switch, a speed sensor built into the ignition distributor (hall sensor), vacuum sensor built into the controller, ignition coil and spark plugs of the NGK BUR 6ET brand. The vacuum sensor ensures control of the engine load and is the main one for adjusting the ignition timing.

Bosch ignition distributor with axial terminals, with built-in Hall sensor. Serves only to determine the engine speed, spark moment and high-voltage current distribution to the spark plugs.