Automobile glow plug fault diagnosis system and diagnosis method

Abstract

The invention relates to an automotive glow plug fault diagnosis system, which includes a battery, an electric control unit, a relay and a glow plug. The electric control unit includes a voltage acquisition circuit, a microprocessor and a switch drive circuit connected in sequence. The negative pole of the electronic control unit and the relay is grounded; the positive input terminal of the electric control unit power supply is connected to the positive pole of the battery, the negative pole input terminal of the power supply is grounded, the relay 87 contact is connected to the positive pole of the glow plug; the negative pole of the glow plug is grounded. The detection method is to measure the voltage at both ends of the battery before and after the relay is turned on by the electronic control unit, and calculate the amplitude of the battery voltage change before and after the relay is turned on; then compare the battery voltage change amplitude with the set threshold to diagnose the fault of the glow plug . Beneficial effects: the invention can accurately detect the fault of the glow plug, promptly remind the vehicle owner to replace it, and ensure the cold start performance of the vehicle or the normal operation of the burner.

Description

technical field [0001] The invention belongs to automobile internal combustion engines, in particular to an automobile glow plug fault diagnosis system and diagnosis method Background technique [0002] Glow plugs are common electrical components in automobiles, and are mainly used for engine air intake preheating and fuel heating, thereby improving the cold start performance of the engine. At the same time, with the increasingly stringent emission standards of automobiles, the emission control system of diesel vehicles is more complicated. Some diesel vehicles use burners for the regeneration of particle traps. The glow plug is an important part of the burner. One of the main causes of failure to ignite properly. Therefore, the fault diagnosis of the glow plug is of great significance to improve the cold start performance of the engine and ensure the normal operation of the emission control system. [0003] When the glow plug fails, it usually causes the resistance to inc...

AI Technical Summary

Problems solved by technology

In this patent, the glow plug control module, which is functionally independent from the engine control module ECM, is used for glow plug control and diagnosis, and the communication and data transmission between the modules makes the system composition more complex.

When the communication signal is missing, it will affect the glow plug control function

Different diagnosis modes need to rely on signals such as engine speed, intake air mass flow and intake air temperature, and the diagnosis logic is more complicated

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