Patent ID: 7167794

Claim:
A control apparatus for an internal combustion engine comprising: a throttle opening detection part that measures a throttle opening of a throttle valve arranged in an intake system of said internal combustion engine; an intake pressure detection part that measures an intake pressure of said intake system; a crank angle detection part that detects a crank angle of said internal combustion engine; a rotational speed detection part that detects a rotational speed of said internal combustion engine; and a control unit that controls said internal combustion engine based on said throttle opening, said intake pressure, said rotational speed and said the crank angle; wherein said intake pressure detection part includes an intake pressure sensor connected to said intake system through tubing; said control unit includes a failure diagnosis section that detects an abnormality of said intake pressure detection part; and said failure diagnosis section detects an open-circuit or a short-circuit of a signal line between said intake pressure sensor and said control unit based on a change in said intake pressure, and also detects a disconnection failure of said tubing of said intake pressure sensor; and wherein an idle detection section detects an idle state of said internal combustion engine; wherein when an amount of change of said intake pressure within one control period of said internal combustion engine in an idle state thereof indicates a predetermined amount of change corresponding to a full open state of said throttle opening, said failure diagnosis section makes a determination that said tubing for said intake pressure sensor is in a disconnection failure state.