ABNORMALITY DIAGNOSIS DEVICE AND ABNORMALITY DIAGNOSIS METHOD FOR BOOSTER DEVICE

The present invention provides an abnormality diagnosis device and an abnormality diagnosis method for a booster device, wherein: when the output of a negative pressure sensor changes in accordance with the decrease in intake pressure, it is determined that the negative pressure sensor is normal; when the negative pressure sensor is normal, a negative pressure pump is operated to lower the pressure in a negative pressure chamber, and it is determined that the negative pressure pump is normal when the pressure decrease is detected by the negative pressure sensor, whereas it is determined that the negative pressure pump is abnormal when the pressure decrease is not detected by the negative pressure sensor; and when the negative pressure chamber reduced in pressure by the negative pressure pump cannot maintain the pressure, it is determined that a negative pressure leakage has occurred. 本发明的助力装置的异常诊断装置及异常诊断方法中，在负压传感器的输出根据进气压的下降而变化时，判断为负压传感器正常，在负压传感器正常时，使负压泵工作以使负压室内的压力下降，如果由负压传感器检测出压力下降，则判定为负压泵正常，如果未由负压传感器检测出压力下降