Fault diagnosis method and diagnosis system of engine temperature control module

Abstract

The invention discloses a fault diagnosis method of an engine temperature control module. The method comprises the steps that in a normal working mode of the temperature control module, whether system voltage is within an allowable range or not is judged; if the system voltage is out of the allowable range, a fault code is output, and corresponding measures are taken; if the system voltage is within the allowable range, equivalent voltage is calculated according to the system voltage, and whether the current equivalent voltage is smaller than a set safety threshold value or not is judged; if the current equivalent voltage reaches or exceeds the safety threshold, whether the continuous working duration of the temperature control module exceeds the limit duration or not is further judged; and if the limit duration is exceeded, the action of a ball valve is forcibly stopped, and the ball valve is continuously controlled to rotate after waiting for the set duration. The invention further provides a fault diagnosis system of the engine temperature control module.

Description

technical field [0001] The invention relates to an engine water cooling system, in particular to a fault diagnosis method and a diagnosis system for an engine temperature control module. Background technique [0002] Currently, the commonly used engine cooling systems on the market usually include mechanical water pumps and thermostats. The physical structure of the thermostat is based on the wax bag. When the water temperature is low, the wax bag is solid. The thermostat valve closes the branch of the coolant leading to the radiator under the action of the spring. When the water temperature is high, the wax bag melts into a liquid. , the volume increases accordingly, and the thermostat valve is pushed to open the radiator branch to cool down. This structure determines that the engine cooling system can only switch between two states of large circulation (radiator participates) and small circulation (radiator does not participate), and cannot control more branches. Based o...

AI Technical Summary

Problems solved by technology

However, traditional thermostats cannot perform self-diagnosis, and if self-diagnosis is required, an additional water temperature sensor needs to be combined

That is, it is necessary to judge whether the value of the main water temperature sensor has risen normally over time. After it rises to the melting threshold of the thermostat wax bag, it is also necessary to combine the auxiliary water temperature sensor to judge whether the water temperature in the current radiator passage has a normal change. To judge whether the thermostat can be opened or closed normally, in addition, it is also necessary to judge whether the water temperature is normal based on the current vehicle working conditions, that is, the thermostat cannot complete this process by itself, and needs to rely on other components through complex control strategies To realize the diagnosis, especially in the condition of the engine not working on the hybrid model, the complexity of this strategy will increase significantly

Furthermore, since the traditional thermostat only has two states of on or off, the ECU cannot judge the intermediate state. Once a fault causes the water temperature to be too high, it often only makes the whole vehicle limp.

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