Method and apparatus for monitoring the intake manifold pressure of an internal combustion engine

There are a method and an apparatus for monitoring the intake manifold pressure of an internal combustion engine (1) proposed in which a measured signal for the intake manifold pressure with a reference signal for the intake manifold pressure is compared. For a deviation of the measured signal for the intake manifold pressure from the reference signal for the intake manifold pressure is a range of tolerance for error-free operated intake and / or exhaust valves (5, 10) defined at least one cylinder (15) of the internal combustion engine (1). It is checked whether the measured signal for the intake manifold pressure from the reference signal for the intake manifold pressure by more than the predefined tolerance range differs. In this case, an erroneous operation of the intake and / or exhaust valves (5, 10) is detected. Otherwise, a fault-free operation of the intake and / or exhaust valves (5, 10) is detected.