Shift Control

A/T CONTROL SYSTEM


Shift Control

The shift is regulated entirely by electronic control to accommodate vehicle speed and varying engine operations. This is accomplished by electrical signals transmitted by the output speed sensor and the ECM (accelerator pedal position sensor). This results in improved acceleration performance and fuel economy.

CONTROL OF SHIFT SOLENOID VALVES A AND B





The TCM activates shift solenoid valves A and B according to signals from the accelerator pedal position sensor and output speed sensor to select the optimum gear position on the basis of the shift schedule memorized in the TCM.
The shift solenoid valve performs simple ON-OFF operation. When set to "ON", the drain circuit closes and pilot pressure is applied to the shift valve.

RELATION BETWEEN SHIFT SOLENOID VALVES A AND B AND GEAR POSITIONS






CONTROL OF SHIFT VALVES A AND B





Pilot pressure generated by the operation of shift solenoid valves A and B is applied to the end face of shift valves A and B.
The figure above shows the operation of shift valve B. When the shift solenoid valve is "ON", pilot pressure applied to the end face of the shift valve overcomes spring force, moving the valve upward.