US Patent 7726281 Cylinder pressure sensor diagnostic system and method

A control module comprising a cylinder torque determination module that determines an indicated torque for a cylinder in an engine based on a pressure in the cylinder, a cylinder torque balancing module that determines a derivative term for the cylinder based on rotation of a crankshaft, and a cylinder pressure error detection module that detects a pressure error for the cylinder based on the indicated torque and the derivative term. A method comprising determining an indicated torque for a cylinder in an engine based on a pressure in the cylinder, determining a derivative term for the cylinder based on rotation of a crankshaft, and detecting a pressure error for the cylinder based on the indicated torque and the derivative term.