Method and apparatus for monitoring an intake air filter

Article of manufacture, comprising a storage medium containing a machine-executable program operative to monitor an intake air filter system for an internal combustion engine of a hybrid powertrain operative to transmit an output torque to a driveline, the engine having a system-controllable throttle valve, the program comprising:

• code to determine a first pressure state comprising an ambient barometric pressure;
• code to determine a second pressure state downstream of the air filter during engine operation at a high flow engine operating point and while controlling the hybrid powertrain to maintain the transmitted output torque to the driveline to meet an operator torque request;
• and,
• code to compare the first and second pressure states.

Method for monitoring an intake air filter for an internal combustion engine of a hybrid powertrain operative to transmit an output torque to a driveline, the engine having a system-controllable throttle valve, comprising:

• determining a first pressure state comprising an ambient barometric pressure;
• determining a second pressure state downstream of the air filter during engine operation at a high mass airflow engine operating point and controlling the hybrid powertrain to maintain the transmitted output torque to the driveline, wherein determining the second pressure state during engine operation at the high mass airflow engine operating point further comprises:
• controlling the engine to operate at a substantially wide open throttle condition;
• and,
• determining the second pressure state downstream of the air filter during the engine operation at the substantially wide open throttle condition;
• and,
• comparing the first and second pressure states.