Supercharged engine diagnostics method and associated engine

A diagnostics method for a supercharged internal combustion engine including a fixed-geometry turbocharger including a compressor through which air admitted to an intake circuit of the engine passes, and a turbine rotationally connected to the compressor by a common shaft and through which exhaust gases from the engine pass in an exhaust circuit of the engine, the engine being associated with:

• a throttle valve for varying a bore section for air admitted to the intake circuit of the engine;
• and
• a wastegate valve mounted in parallel with the turbine in the exhaust circuit of the engine to vary a proportion of exhaust gases from the engine passing through the turbine,
• the method comprising:
• calculating a first integral with respect to time of a measurement of atmospheric pressure during a calculation time;
• calculating an integral with respect to time of a measurement of the boost pressure during the calculation time;
• calculating a second integral with respect to time of a measurement of the atmospheric pressure during the calculation time;
• calculating two diagnostics criteria dependent on the first integral with respect to time of the atmospheric pressure, on the integral with respect to time of the boost pressure, and on the second integral with respect to time of the atmospheric pressure;
• comparing the first diagnostics criterion with a first diagnostics threshold and comparing the second diagnostics criterion with a second diagnostics threshold;
• and
• diagnosing a fault when one of the two diagnostics criteria at least is below its associated diagnostics threshold.