Method for detecting a wiring fault in a capacitive sensor

A method for detecting a wiring fault in a capacitive sensor (1), such as a knock sensor, connected, via a passive acquisition interface (5), to a communication port (P1), that can be configured in either input mode or output mode, of a computer (2), wherein the communication port (P1) is configured in output mode, and a square wave voltage Vn capable of at least partially charging the capacitors (C6, C7, C8a, C8b, C10) of the acquisition interface (5) and the capacitive sensor (1) is generated during a time interval Tc, after which the communication port is switched to its input mode, so that at least one data element representative of the voltage of the capacitors and of the capacitive sensor is acquired, and finally these data are compared with previously stored reference data so that a wiring fault can be deduced if there is no matching between the data.