Abstract: An ECU (19) outputs control signals to an electric booster (16) of a fluid-pressure generating device (5) and to an ESC (22). In this way, the establishment and cutting off of communication through pressure-increase control valves (29), (29?), (31), and (31?) of the ESC (22) are controlled to connect each of wheel cylinders (1) to (4) in turn to the master cylinder (8). In doing so, the electric booster (16) is controlled for each of the wheel cylinders (1) to (4) to measure a stroke of a piston (10), (11) of a master cylinder (8), or a volume of brake fluid proportional to the stroke of the piston (10), (11), and a fluid pressure detected by fluid-pressure sensors (20) and (21). The fluid volume-pressure characteristic of each of the wheel cylinders (1) to (4) so determined is used for comparison to detect any atmospheric air in each pipeline.

Abstract: A second ECU determines whether or not there is an abnormality in a hydraulic-pressure sensor in a first cycle based on a detection value of the hydraulic-pressure sensor, and outputs a signal indicating a determination of an occurrence of the abnormality to a first ECU via a signal line when determining the occurrence of the abnormality in the hydraulic-pressure sensor. The first ECU receives the detection value of the hydraulic-pressure sensor through communication from the second ECU via the signal line to determine whether or not there is the abnormality in the hydraulic-pressure sensor in a second cycle that is shorter than the first cycle. When determining that the hydraulic-pressure sensor is abnormal, the first ECU controls driving of an electric actuator based on a braking command from an operation-amount detection sensor without using the detection value of the hydraulic-pressure sensor determined to be abnormal.

Abstract: An ECU (19) outputs control signals to an electric booster (16) of a fluid-pressure generating device (5) and to an ESC (22). In this way, the establishment and cutting off of communication through pressure-increase control valves (29), (29?), (31), and (31?) of the ESC (22) are controlled to connect each of wheel cylinders (1) to (4) in turn to the master cylinder (8). In doing so, the electric booster (16) is controlled for each of the wheel cylinders (1) to (4) to measure a stroke of a piston (10), (11) of a master cylinder (8), or a volume of brake fluid proportional to the stroke of the piston (1C), (11), and a fluid pressure detected by fluid-pressure sensors (20) and (21). The fluid volume-pressure characteristic of each of the wheel cylinders (1) to (4) so determined is used for comparison to detect any atmospheric air in each pipeline.

Abstract: A second ECU determines whether or not there is an abnormality in a hydraulic-pressure sensor in a first cycle based on a detection value of the hydraulic-pressure sensor, and outputs a signal indicating determination of occurrence of the abnormality to a first ECU via signal line when determining occurrence of the abnormality in the sensor. The first ECU receives the detection value of the hydraulic-pressure sensor through communication from the second ECU via the signal line to determine whether or not there is the abnormality in the hydraulic-pressure sensor in a second cycle shorter than the first cycle. When determining that the hydraulic-pressure sensor is abnormal, the first ECU controls driving of an electric actuator based on a braking command from an operation-amount detection sensor without using the detection value of the hydraulic-pressure sensor determined as abnormal.

Abstract: When a vehicle control unit is to be exchanged, out of learning data stored in a control memory of the control unit to be exchanged, the learning data correlating to vehicle parts to be exchanged at the same time are corrected to initial values, and the learning data after correction processing are written to a control memory of a new control unit.

Abstract: The present invention enables reliable shift to a fail-safe processing upon detection of failure by RAM diagnosis. To this end, the diagnosis result of the RAM diagnosis is doubly stored, as flags, into mutually different two addresses of the RAM; and a fail-safe processing is conducted based on the doubly stored diagnosis result flags when at least one of the flags indicates existence of failure. Otherwise, the diagnosis result of the RAM diagnosis is stored, as a flag, into a predetermined register; and a fail-safe processing is conduced based on the diagnosis result flag stored in the register such that the fail-safe processing is conducted when the flag indicates existence of failure.