Engine control method and device

Abstract

An engine control method and compensation suitable for the case that both of two manifold pressure sensors in individual groups have failed. When detection outputs from two manifold pressure sensors are different from each other, a first comparing section determines that one of the two sensors is abnormal. A manifold pressure estimating section calculates an estimated manifold pressure value according to an engine speed, throttle opening, and atmospheric pressure. A calculating section calculates a difference ΔPMb between the detection output PMb and the estimated value PMcal. A calculating section calculates a difference ΔPMa between the detection output PMa and the estimated value PMcal. A second comparing section identifies an abnormal one of these two manifold pressure sensors corresponding to a larger one of these differences ΔPMa and ΔPMb. When the remaining manifold pressure sensor has also failed, the estimated value PMcal is used as a substitutional value, then continuing the engine control.