On-board diagnostics of a turbocharger system

A method for on-board diagnostics of a turbocharger system for a vehicle, the turbocharger system being fluidly connected to an exhaust manifold of a combustion engine, wherein the turbocharger system comprises:

• a turbocharger turbine operable by exhaust gases from the exhaust manifold,
• a pressurized gas reservoir being fluidly connectable to the turbocharger turbine,
• a valve configured to control flow of pressurized gas from the pressurized gas reservoir to the turbocharger turbine, and
• a sensor,
• wherein the method comprises the steps of
• injecting a test pulse of pressurized gas from the pressurized gas reservoir to drive the turbocharger turbine by means of controlling the valve,
• measuring movement of the turbocharger turbine caused by the injected pressurized gas directly with the sensor,
• collecting data from the sensor, and
• evaluating an operational response of the turbocharger turbine as a result of the injected test pulse of pressurized gas, based on the collected data, wherein evaluating the operational response of the turbocharger turbine comprises the further step of
• determining that the evaluated operational response of the turbocharger turbine indicates no, by the sensor, measurable response of the turbocharger turbine as the result of the injected test pulse,
• injecting a further pulse of pressurized gas from the pressurized gas reservoir to drive the turbocharger turbine, wherein the further pulse is longer than the previous pulse,
• measuring movement of the turbocharger turbine caused by the injected pressurized gas directly with the sensor, and
• collecting data from the sensor,
• evaluating the operational response of the turbocharger turbine as a result of the injected further pulse of pressurized gas based on the collected data, wherein the further steps of the method are repeated until the evaluated operational response of the turbocharger turbine indicates, by the sensor measurable, response of the turbocharger turbine as the result of the injected further pulse.