System and method for monitoring combustion chamber pressure and control system using the same

In a monitoring system and method for monitoring pressure in a combustion chamber of an internal combustion engine, a sensor is operable to sense movement of a valve while the valve is in its closed position. The sensor generates data indicative of the sensed movement of the valve. A control system is in communication with the sensor to receive the data indicative of the sensed movement of the valve in the closed position thereof. The control system is operable to determine the pressure in the combustion chamber based at least in part on the sensed movement of the valve. In other aspects, operation of the engine is adjusted based at least in part on the determined pressure in the combustion chamber.