Hydraulic pressure diagnostic detection for a vehicle

A hydraulic pressure control unit (5, 5A) used for a brake system (10, 10A) of a vehicle (100, 100A), the hydraulic pressure control unit comprising:

• a hydraulic pressure control mechanism (51, 51A) including an inlet valve (31) that is provided to a primary channel (25) communicating a master cylinder (21) and a wheel cylinder (24), an outlet valve (32) that is provided to a secondary channel (26) through which a hydraulic fluid in the wheel cylinder (24) is released to an intermediate portion (25a) of the primary channel (25), a pump (34) that is provided on a downstream side of the outlet valve (32) in the secondary channel (26), and a motor (35) that drives the pump (34);
• and
• a controller (52, 52A) that controls operation of the hydraulic pressure control mechanism (51, 51A), wherein
• the controller (52, 52A) includes a diagnosis section (522b) that executes a diagnostic mode to diagnose presence or absence of abnormality in the hydraulic pressure control mechanism (51, 51A) on the basis of a current fluctuation of the motor (35) in a state where the pump (34) is driven by the motor (35),
• wherein, in the diagnostic mode, the diagnosis section (522b) drives the pump (34) by the motor (35) in a state where the inlet valve (31) is closed, and
• wherein in the case where a brake operation is performed by a driver of the vehicle (100, 100A) during execution of the diagnostic mode, which is executed during travel of the vehicle (100, 100A), the diagnosis section (522b) brings the inlet valve (31) into an open state from a closed state.