Control of Shift Solenoid Valves A and B
The TCM activates shift solenoid valves A and B according to signals from the ECM (throttle opening) and revolution 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
| Shift solenoid valve | Gear position | ||||
|---|---|---|---|---|---|
| D1, 21, 11 | D2, 22, 12 | D3 | D4 (O/D) | N-P | |
| A | ON (Closed) | OFF (Open) | OFF (Open) | ON (Closed) | ON (Closed) |
| B | ON (Closed) | ON (Closed) | OFF (Open) | OFF (Open) | ON (Closed) |