Electronic Control Device and Diagnosis Method of Electronic Control Device

A diagnosis method of an electronic control device, the diagnosis method comprising:

• a step (a) of turning off an ignition signal;
• a step (b) of starting a first timer and a diagnostic timer of a first power supply unit;
• a step (c) of shutting down a second power supply unit and a microcomputer;
• a step (d) of counting up respective timer values of the first timer and the diagnostic timer at predetermined time intervals during a key-off time period;
• a step (e) of comparing the first timer and the diagnostic timer every predetermined count cycle;
• and
• a step (f) of determining whether or not a change amount of a timer value of each of the first timer and the diagnostic timer is within a predetermined range,
• wherein in the step (f), if the change amount of the timer value of each of the first timer and the diagnostic timer is within the predetermined range, the first timer is determined as being normal, and if the change amount of the timer value of each of the first timer and the diagnostic timer is beyond the predetermined range, the first timer is determined as being abnormal.