Vehicle-mounted electronic system and fault diagnosis method thereof, readable storage medium and vehicle

The invention discloses a vehicle-mounted electronic system and a fault diagnosis method thereof, a readable storage medium and a vehicle, the vehicle-mounted electronic system comprises a battery and an electronic control unit, and the method comprises the following steps: detecting the state of the vehicle-mounted electronic system; under the condition that the state of the vehicle-mounted electronic system meets at least one preset condition, first duration time is detected, the first duration time is duration time when the state of the vehicle-mounted electronic system meets the preset condition, and the preset condition comprises a first preset condition and a second preset condition; the first preset condition is a state condition corresponding to a safety critical fault of the battery, and the second preset condition is a state condition corresponding to an electronic and electrical fault of the electronic control unit; the fault type of the vehicle-mounted electronic system is determined according to the first duration time, preset first time and preset second time, the first time is the confirmation time corresponding to the safety critical fault, the second time is the confirmation time corresponding to the electronic and electrical fault, and the first time is longer than the second time.