Patent ID: 7177756
Filing Date: 2007-02-13
Classification: F02D,Y02T

Abstract:
1. A method for detecting a defect in at least one of an intake-manifold pressure sensor and an ambient-pressure sensor in an internal combustion engine having a variable valve timing, comprising: ascertaining a pressure upstream from a throttle valve of the internal combustion engine; ascertaining a pressure in an intake manifold of the internal combustion engine; calculating a pressure difference by subtracting the pressure in the intake manifold from the pressure upstream from the throttle valve; comparing the pressure difference to at least one of: a) a first threshold value during throttleless operation of the internal combustion engine; and b) a second threshold value during one of throttled and unthrottled operation of the internal combustion engine; and determining that at least one of the intake-manifold pressure sensor and the ambient-pressure sensor is defective, if at least one of: a) the pressure difference is greater than the first threshold value; and b) the pressure difference is less than the second threshold value.