| 摘要 |
PROBLEM TO BE SOLVED: To suppress degradation of controllability due to frictional resistance in very low temperature of a range changeover control system, and to sufficiently secure safety of a vehicle.SOLUTION: An oil temperature (temperature having correlation with temperature of motor 12) of an automatic transmission 27 is detected by an oil temperature sensor 33 in starting a microcomputer 41, and whether a very low temperature state exists or not is determined on the basis of that the oil temperature is lower than a prescribed value or not. In a case when the very low temperature state is determined, stop energization control to stop and hold the motor 12 is executed by simultaneously energizing all phases of the motor 12 when a brake of a vehicle (for example, electric parking brake) is in an operated state and the vehicle is in a stopped state. Thus the motor 12 can be warmed up by energizing and heating a winding of the motor 12 while stopping and holding a range changeover mechanism 11, and frictional resistance of a movable portion of the motor 12 can be reduced by reducing viscosity of a lubricant inside of the motor 12.SELECTED DRAWING: Figure 2 |
