As one example, an engine
system for a vehicle is provided, comprising an
internal combustion engine including an air intake
system and an exhaust
system; a first
turbocharger including a first compressor arranged along a first
branch of the air intake system, a first
turbine arranged along a first
branch of the exhaust system, and a first
turbine bypass passage include a first
wastegate; a second
turbocharger including a second compressor arranged along a second
branch of the air intake system, a second
turbine arranged along a second branch of the exhaust system, and a second turbine bypass passage including a second
wastegate; a first
exhaust gas sensor arranged along the first branch of the exhaust system downstream of the first turbine and first
wastegate; a second
exhaust gas sensor arranged along the second branch of the exhaust system downstream of the second turbine and the second wastegate; and a
control system configured to command both the first wastegate and the second wastegate to a closed position or an opened position and to indicate one of said wastegates as unresponsive to said command in response to a
temperature difference between the first and second branches indicated by the first and second
exhaust gas sensors.