| 摘要 |
The hydraulic switch malfunction assessment device is provided with: a solenoid valve (36), which is disposed on the hydraulic circuit (35) of an automatic transmission installed in a vehicle and has a property such that changes in supplied electric current results in the valve changing the working hydraulic pressure supplied to a frictional engagement element (33) of the automatic transmission; a hydraulic switch (48), which is interposed between the solenoid valve (36) and the frictional engagement element (33), outputs an ON signal when the working hydraulic pressure is at or above a specified threshold, and outputs an OFF signal when the working hydraulic pressure is less than the threshold; a detection means (12a) for detecting the state of operation of the solenoid valve (36); and a malfunction assessment means (12b) for assessing the malfunction of the hydraulic switch (48) on the basis of the state of operation of the solenoid valve (36) detected by the detection means (12a) and the signal of the hydraulic switch (48). When specified running conditions are met, the malfunction assessment means (12b) controls the supplied electric current to a specified electric current value or less and assesses the malfunction of the hydraulic switch (48). |
