Patent ID: 8051659

Claim:
A control apparatus for an internal combustion engine, comprising: an exhaust gas recirculation unit that recirculates exhaust gas back from an exhaust passage, at a portion downstream of a turbine of a turbocharger and a catalyst, to an intake passage, at a portion upstream of a compressor of the turbocharger; an intercooler that is provided in the intake passage, at a position downstream of a position to which the exhaust gas is recirculated back by the exhaust gas recirculation unit; a bypass passage through which an intake air flow bypasses the intercooler; a pH determination unit that determines a pH of condensed water obtained from the exhaust gas recirculated back by the exhaust gas recirculation unit by estimation or detection; a corrosion determination unit that determines whether the pH of the condensed water obtained from the exhaust gas is at a level at which the intercooler corrodes, based on the pH determined by the pH determination unit; and a bypass control unit that executes a control for cutting off an intake air flow toward the intercooler to direct the intake air flow only to the bypass passage, when the corrosion determination unit determines that the pH of the condensed water obtained from the exhaust gas is at the level at which the intercooler corrodes in a state where the exhaust gas is recirculated back by the exhaust gas recirculation unit.