Patent ID: 6883318

Claim:
A method of controlling an internal combustion engine when the engine is operating in an engine braking mode, the engine having at least one cylinder and an intake manifold that supplies a controllable airflow to the at least one cylinder, wherein when the engine is operating in the engine braking mode an exhaust valve for the cylinder is prematurely opened to dissipate power, the method comprising: determining a desired mass airflow rate to the at least one cylinder when the engine is operating in the engine braking mode; determining an actual mass airflow rate to the at least one cylinder when the engine is operating in the engine braking mode; comparing the desired mass airflow rate to the actual mass airflow rate: and controlling the airflow based on the comparison such that the actual mass airflow rate tracks the desired mass airflow rate, wherein determining the actual mass airflow rate further comprises: determining an engine speed; determining an intake manifold air pressure; determining an intake manifold air temperature; determining a number of braking cylinders; determining a correction factor based on the number of braking cylinders; and determining the actual mass airflow rate based on the engine speed, the intake manifold air pressure, the intake manifold air temperature, and the correction factor.