3.3.1. General information

Operation of the electronic automatic transmission in the block with the main transfer is divided into three systems: the mechanism of electronic control, the hydraulic mechanism of management and the mechanism of transmission (turns on the hydrotransformer).
Receiving signals from switches and sensors in entrance system, the electronic block of the mechanism of electronic control (RSM) gives a signal which coordinates the existing traffic conditions with the linear solenoid, the switching solenoids and solenoids of a running cycle in the hydraulic mechanism of management.
In turn, the hydraulic mechanism of management, receiving signals from the RSM block, changes hydraulic channels in the block of managing directors of valves and operates coupling inclusion pressure.

Fig. 3.71. Block diagram of operation of the automatic FN4A-EL transmission of the Mazda 3 car: 1 – transmission mechanism; 2 – hydraulic mechanism of management; 3 – mechanism of electronic control; 4 – hydrotransformer; 5 – couplings, brakes; 6 – planetary transfer; 7 – differential; 8 – the block of the operating valves; 9 – solenoids of switching D, E; 10 – solenoid of regulation of pressure (linear type); 11 – solenoids of switching A, B, C (solenoids of a running cycle); 12 – oil pump; 13 – RSM block; 14 – oil pressure sensor signal; 15 – vehicle speed; 16 – temperature of working liquid in the transmission; 17 – speed of rotation of the drum of the coupling of the forward course; 18 – speed of rotation of a bent shaft of the engine; 19 – signal of provision of a butterfly valve; 20 – couplings, inclusion of brakes, shutdown pressure; 21 – power stream; 22 – the operating signal of hydraulic pressure; 23 – electronic signal; 24 – wheel

Pressure in the pipeline is regulated by the linear solenoid. Hydraulic channels are changed by the switching solenoids (solenoids of switching of D and E), solenoids of a running cycle operate pressure of inclusion of coupling (solenoids of switching A, B, and C) (cm. fig. 3.71).
In the transmission mechanism driving force from the engine is transmitted through the hydrotransformer to the transmission in the block with the main transfer.

Fig. 3.72. Cross section of the automatic FN4A-EL transmission of the Mazda 3 car: 1 – hydrotransformer; 2 – oil pump; 3 – coupling of the forward course; 4 – planetary transfer of the forward course; 5 – planetary transfer of a backing; 6 – coupling 3–4; 7 – coupling of inclusion of a backing; 8 – tape of a brake 2–4; 9 – brake of transfer of a backing and low gear; 10 – unilateral coupling; 11 – gear wheel of a main shaft; 12 – gear wheel of a secondary shaft; 13 – leading gear wheel of the main transfer; 14 – differential

The transferred driving force operates each coupling and a brake according to pressure of inclusion of coupling from solenoids of a running cycle. Planetary transfers change the transfer relation for optimization of driving force. Further driving force is transmitted through differential to a shaft of the drive of wheels and then – to wheels.