| 摘要 |
Hydraulic pressure applied to an LR/B is controlled by a first solenoid valve when a forward-movement range is selected, and is controlled by a second solenoid valve when a backward-movement range is selected. In addition, in the forward-movement range, the second solenoid valve controls hydraulic pressure applied to an OD/C which couples at a different gear position from the LR/B. When both solenoid valves fall into non-excitation states due to the breaking of an electric signal line, the failure of an AT ECU or the like, the output hydraulic pressures of the solenoid valves is held high and low, respectively. Therefore, even in this case, double coupling of the LR/B and the OD/C can be prevented in the forward-movement range as well as a predetermined gear position can be established in each of the forward-movement range and the backward-movement range.
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