The engine electronic control unit monitors the engine operating conditions using signals from the corresponding sensors. Based on these signals, the electronic control unit calculates the required ignition advance angle and sends a control signal to the switch. High voltage is distributed to the spark plugs in accordance with the engine operating order and causes a spark discharge between the spark plug electrodes, which ignites the fuel-air mixture.
Complex (combined) ignition unit (contactless ignition system unit) includes; the switch, the ignition coil, the spark distributor among the engine cylinders, as well as the rotors and inductive coils of the crankshaft angular position sensor and the camshaft angular position sensor.
The switch periodically interrupts the primary current coming from the electronic engine control unit (iGT signal), and thus creates a spark discharge on the spark plugs. In addition, in order to increase the reliability of the ignition system, at the moment of spark formation, information about this (iGF signal) is supplied to the electronic engine control unit. The ignition coil consists of a closed core, a primary winding that encloses the core, and a secondary winding that encloses the primary winding. This design allows for the creation of high voltage capable of causing a powerful spark discharge in the gap between the spark plug electrodes. The ignition distributor ensures that high voltage is distributed to the spark plugs of each cylinder in accordance with the engine operating order.
The NE induction coil with a magneto-electric pulse generator allows determining the angular position of the crankshaft, and the G induction coil - the angular position of the camshaft, which is necessary for correct determination of the ignition timing.
Note: On some 4A-FE engines (lean bum system option) the camshaft position sensors use two inductive coils G1 and G2.
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