Output load diagnosis circuit of vehicle-mounted ECU relay and diagnosis method thereof

Abstract

The invention relates to automobile detection, in particular to an output load diagnosis circuit of a vehicle-mounted ECU relay and a diagnosis method thereof. The output load diagnosis circuit comprises a controller, a relay drive circuit, a relay, a test voltage circuit, a to-be-diagnosed circuit, a field-effect tube drive circuit, a level input circuit, and a current amplifying circuit. The controller is connected to the relay drive circuit connected to the relay. The controller is respectively connected to the test voltage circuit, the field-effect tube drive circuit, and the level input circuit; the test voltage circuit and the field-effect tube drive circuit are respectively connected with the to-be-diagnosed circuit through the relay; and the field-effect tube drive circuit and thelevel input circuit are respectively connected to the current amplifying circuit. Therefore, a defect that the load current cannot be effectively diagnosed in the prior art can be overcome effectively.

Description

technical field [0001] The invention relates to automobile detection, in particular to a vehicle-mounted ECU relay output load diagnosis circuit and a diagnosis method thereof. Background technique [0002] At present, the on-board module can choose relay, MosFet, H half bridge, H full bridge, IGBT, etc. when driving high-power loads, but high-power H half bridge, H full bridge, MosFet, IGBT, etc. have high cost and difficult design question. In actual design, the drive of high-power loads (wiper motors, window and door lock motors, and lamps) is mainly driven by relay output, and the output of the relay is in the form of contacts, without the function of current diagnosis. When the load is short-circuited to the power supply or the vehicle body, abnormal working conditions such as sparks and high current in the wiring harness circuit are prone to occur, which may cause the vehicle to catch fire in severe cases, which does not meet the specification requirements. Contents...

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Problems solved by technology

[0004] In view of the above-mentioned shortcomings existing in the prior art, the present invention provides a vehicle-mounted ECU relay output load diagnosis circuit and its diagnosis method, which can effectively overcome the defect that the load cannot be effectively diagnosed in the prior art

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