Fault diagnosis method and - a device for manifold pressure sensors

摘要

In a control device, the two system of manifold pressure detection systems for the purpose of the fail-safe performance, a failed manifold pressure sensor specified. A first comparison unit (29) outputs an anomaly signal, if a difference δp between the manifold pressures pma and pmb, each of two sensors (85a, 5b) are detected, is greater than a threshold value dp. A manifold pressure estimation unit (30) estimates the manifold pressure on the basis of the engine speed ne, a throttle opening plp and an atmospheric pressure paa. The difference computing unit (31) calculates a difference between the detected δpmb manifold pressure pmb and the estimated manifold pressure pma. The difference computing unit (32) calculates a difference between the detected δpma manifold pressure pma and the estimated manifold pressure pmcal. A second comparison unit (33) compares the difference and the difference δpma δpmb in response to the above cited anomaly signal. The precipitated manifold pressure sensor is specified as a function of whether the difference δpma or the difference is greater δpmb.