Mono-Jetronic
In engine technology, the Mono-Jetronic is an indirect, central, intermittent (skipping), electronically controlled central point injection (one injection valve for all cylinders) and is a brand name of Robert Bosch GmbH. With the Mono-Jetronic, the basic fuel quantity and the basic injection time are determined by the signals of the throttle valve angle and the engine speed (basic mixture). Further signals such as air temperature, coolant temperature, mixture composition ( lambda probe ) are required for more precise determination of the fuel quantity (correction mixture ). The fuel-air mixture is distributed to the individual cylinders via the intake manifold (which can be heated electrically or using waste heat from the engine ). The Monojetronic also has an overrun cut-off that is activated via a switch in the throttle valve actuator, i.e. H. No fuel is injected in overrun mode. The idling speed is controlled by the throttle valve motor, whereby the cooling water temperature (cold start) largely determines the idling speed. Furthermore, in vehicles with a catalytic converter, the valves for regenerating the activated carbon filter are activated. The system pressure is 0.75–1 bar and is regulated by a spring-loaded pressure regulator. The speed is limited by switching off the injection valve. The Mono-Jetronic control unit only contains the injection control, the ignition control is separate from the injection, only the speed signal is transferred to the injection system.
The further development of the Mono-Jetronic is the Mono-Motronic.
Diagnostic function
The Mono-Jetronic is equipped with OBD I which also stores the errors. The error codes are output by flashing codes both via diagnostic devices and by flashing the engine fault light. The error codes have 4 digits and the pauses between the pulses are 2.5 s, with a start bit of 2.5 s being set before each code.
Selection of error codes (Audi 80 engine code PM): 1-1-1-1 control unit defective, 2-3-4-2 lambda probe defective, 2-1-2-2 speed signal from TSZ-h missing, 4-4-4- 4 No errors, 0-0-0-0 error output end
literature
- Karl-Heinz Dietsche, Thomas Jäger, Robert Bosch GmbH: Automotive pocket book. 25th edition, Friedr. Vieweg & Sohn Verlag, Wiesbaden, 2003, ISBN 3-528-23876-3