Valvetrain fault indication systems and methods using engine misfire

A system for a vehicle, comprising:

• a first electronic circuit that selectively indicates that a coefficient of variation (COV) of indicated mean effective pressure (IMEP) of a cylinder of an engine is greater than a predetermined value;
• a second electronic circuit that controls lifting of a valve of the cylinder of the engine and that, in response to the first electronic circuit indicating that the COV of IMEP of the cylinder is greater than the predetermined value, transitions lifting of the valve from one of a low lift state and a high lift state to the other one of the low lift state and the high lift state;
• and
• a third electronic circuit that selectively indicates that a fault is present in a variable valve lift (VVL) mechanism of the cylinder based on whether the first electronic circuit indicates that the COV of IMEP of the cylinder is greater than the predetermined value after the transition to the other one of the low lift state and the high lift state.