Method for quality assurance for an exhaust gas behaviour in a motor vehicle , preferably in a hybrid motor vehicle, in particular in a plug-in hybrid motor vehicle, the method involving: - monitoring an onboard diagnosis function of the motor vehicle , the onboard diagnosis function being relevant to the exhaust gas behaviour of the motor vehicle, - providing a trip counter , the trip counter being indicative of a number of trips by the motor vehicle , - providing a diagnosis counter for the onboard diagnosis function of the motor vehicle that is affected by the monitoring , - providing a diagnosis frequency setpoint value , - incrementing the trip counter after the beginning of a driving cycle of the motor vehicle and a predetermined driving time of the motor vehicle , characterized in that the method further involves: - forming a diagnosis frequency actual value , by means of a suitable combination of the diagnosis counter with the trip counter , - forming a difference between the diagnosis frequency setpoint value and the diagnosis frequency actual value , - if the formed difference between the diagnosis frequency setpoint value and the diagnosis frequency actual value is below a difference threshold: - selecting a control method from a control method group, each control method of the control method group being indicative of an applicable motor actuation of a drive apparatus of the motor vehicle , wherein the selected control method is suitable for successfully completing a currently running onboard diagnosis of the onboard diagnosis function and successfully initiating and completing a non-running onboard diagnosis of the onboard diagnosis function , and after completion of the onboard diagnosis of the onboard diagnosis function : - incrementing the diagnosis counter of the onboard diagnosis function , and - resetting the motor actuation to an original motor actuation, according to a state before the selection of the control method . - monitoring an onboard diagnosis function of the motor vehicle , the onboard diagnosis function being relevant to the exhaust gas behaviour of the motor vehicle, - providing a trip counter , the trip counter being indicative of a number of trips by the motor vehicle , - providing a diagnosis counter for the onboard diagnosis function of the motor vehicle that is affected by the monitoring , - providing a diagnosis frequency setpoint value , - incrementing the trip counter after the beginning of a driving cycle of the motor vehicle and a predetermined driving time of the motor vehicle , - forming a diagnosis frequency actual value , by means of a suitable combination of the diagnosis counter with the trip counter , - forming a difference between the diagnosis frequency setpoint value and the diagnosis frequency actual value , - if the formed difference between the diagnosis frequency setpoint value and the diagnosis frequency actual value is below a difference threshold: - selecting a control method from a control method group, each control method of the control method group being indicative of an applicable motor actuation of a drive apparatus of the motor vehicle , wherein the selected control method is suitable for successfully completing a currently running onboard diagnosis of the onboard diagnosis function and successfully initiating and completing a non-running onboard diagnosis of the onboard diagnosis function , and - incrementing the diagnosis counter of the onboard diagnosis function , and - resetting the motor actuation to an original motor actuation, according to a state before the selection of the control method . <EOS>