Diagnosis apparatus for internal combustion engine
AssigneeHitachi, Ltd.
InventorsYoichi Iihoshi, Shin Yamauchi, Toshio Hori, Yoshikuni Kurashima
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Abstract
In a diagnosis apparatus for an internal combustion engine which determines the abnormality of a linear A/F sensor which is disposed on the upstream side of a catalyst of the engine and detects the A/F of exhaust gas, the apparatus includes a response/gain deterioration detection unit that separately detects the response deterioration in which the response of the linear A/F sensor is delayed and the gain deterioration in which the detection sensitivity of the linear A/F sensor is abnormal.
Claims20
A diagnosis apparatus for an internal combustion engine which diagnoses a linear A/F sensor which is disposed within an exhaust pipe of the engine and detects an A/F of exhaust gas, comprising:
- a unit which separately detects response deterioration and gain deterioration of the linear A/F sensor.
A diagnosis apparatus for an internal combustion engine, comprising:
- a catalyst deterioration diagnosis mode which detects deterioration of a catalyst based on outputs of a linear A/F sensor and an A/F sensor, the catalyst being disposed within a path of exhaust gas of the engine, the linear A/F sensor being disposed on an upstream side of the catalyst, and the A/F sensor being disposed on a downstream side of the catalyst;
- and
- a linear A/F sensor deterioration diagnosis mode in which a frequency of a diagnosis mode for diagnosing the linear A/F sensor is lower than a frequency of a control mode for controlling the A/F, wherein both the catalyst deterioration diagnosis mode and the linear A/F sensor deterioration diagnosis mode are carried out.
A diagnosis apparatus for an internal combustion engine which includes a linear A/F sensor which is disposed within an exhaust pipe of the engine and detects an A/F of exhaust gas, comprising:
- an abnormality alarm unit which notifies gain deterioration of the linear A/F sensor through a display or a sound signal.
Dependencies are inferred from the claim text.