Method for controlling a wastegate valve of a turbocharger

A turbocharger system for an internal combustion engine of a vehicle, the turbocharger system including:

• a turbocharger having:
• a turbine housing;
• and
• a turbine disposed in the turbine housing;
• a bypass conduit defined by the turbine housing for selectively diverting exhaust gases away from the turbine;
• a wastegate valve disposed in the bypass conduit for controlling flow of the exhaust gases through the bypass conduit;
• an actuator having an output member operatively connected to the wastegate valve, the actuator movable between an open position and a previously stored closed position;
• and
• a wastegate controller communicatively coupled to the actuator for controlling operation of the actuator for controlling the wastegate valve, the wastegate controller being configured to:
• (a) receive a closed position request from an engine control unit of the vehicle;
• (b) move the actuator toward the previously stored closed position until a predetermined actuator position is reached;
• (c) once the predetermined actuator position is reached, receive an actual value indicative of force exerted by the actuator;
• and
• (d) comparing the actual value indicative of force exerted by the actuator to an expected value indicative of force exerted by the actuator;
• in response to the actual value indicative of force being less than the expected value indicative of force,
• (e) move the actuator away from the open position by a predetermined amount;
• (f) replace the previously stored closed position with a position of the actuator following step (e);
• and
• (g) repeat steps (d) to (f) until the actual value indicative of force exerted by the actuator is greater than the expected value indicative of force exerted by the actuator.