The invention relates to a reciprocating piston machine, in particular with a variable compression ratio, of at least one cylinder with a piston and a connecting rod which is connected to the piston and to a crankshaft of the reciprocating piston machine. The reciprocating piston machine also has a first sensor which is arranged in a cylinder wall of the at least one cylinder and is configured to detect relative movement between a piston skirt of the piston and the cylinder wall. The invention further relates to a method (100) for diagnosing and/or controlling such a reciprocating piston machine (1), in particular with a variable compression ratio, and a system which is suitable therefor.