Abstract: A method is provided for monitoring vehicle function components using a diagnostic device taken along in the vehicle. A multiplicity of individual test routines are carried out, respectively, given the presence of start conditions specific to the test routine, in a fixed, cyclic sequence in order to obtain information on the presence or absence of a fault with respect to the relevant function components. Data relating to a first-time execution of a respective test routine is retrievably stored. With the aid of this data, before activation of a test routine pending according to a sequence provided it is determined given the presence of appropriate start conditions whether the test routine has already been performed at least once and whether at least one other activatable test routine exists which has not yet been performed. If no, the pending test routine is activated, otherwise, the test routine not yet performed is activated.