Method for diagnosing faults in the operation of a fuel heating system associated with an internal combustion engine

A method for self-diagnostic of a fuel heating system including at least one engine control unit (ECU) that includes a respective microcontroller, and at least one heating control unit (HCU) that includes a respective microcontroller, both being fed by at least one tension source (10) and interconnected to each other and to at least one heating element (13) through an electronic circuit that still includes at least one main relay (11) and at least one secondary relay (12), wherein the heating control unit (HCU):

• performs a diagnostic of at least one heating element (13) based on at least one of the following:
• short-circuit detection for one grounding spot, short-circuit detection for the tension source (10), open circuit detection and overheating detection;
• performs a diagnostic of an operational status of said at least one secondary relay (12);
• performs a diagnostic of itself and of respective data connection means (14) based on at least one of the following:
• overheating detection routines in a printed circuit board, ground shift displacement detection;
• error detection in a power stage, communication error detection, memory integrity detection and integrity detection in relation to the respective microcontroller.