Diagnosis method and module for engine water temperature sensor

Abstract

The invention discloses a diagnosis method and module for an engine water temperature sensor. The method comprises the steps of S01, obtaining a voltage value of the engine water temperature sensor; S02, judging whether the voltage value is within the range of a voltage threshold value or not, and if yes, executing S03; S03, obtaining environment temperature and coolant temperature; S04, judging whether the difference value of the environment temperature and the coolant temperature is smaller than or equal to a refrigerator starting value or not, and if yes, executing S05; S05, intermittentlyobtaining N coolant temperatures within a preset time; S06, comparing the N coolant temperatures with ideal temperatures corresponding to obtaining times of all the coolant temperatures, and if the probability that all the coolant temperatures are larger than the corresponding ideal temperatures exceeds preset probability, sending out signals that the engine water temperature sensor is normal. Bymeans of the diagnosis method for the engine water temperature sensor, after the engine water temperature sensor is diagnosed multiple times, whether the engine water temperature sensor breaks down ornot is judged, and the engine water temperature sensor is more accurately and reliably diagnosed.

Description

technical field [0001] The invention relates to the field of engine performance, in particular to a diagnosis method and module of an engine water temperature sensor. Background technique [0002] The engine water temperature sensor is one of the very important sensors in the engine electronic control system. Its function is to measure the engine coolant temperature as a reference value for fuel injection control, air intake control, and cooling fan control. The engine coolant temperature measured by the engine water temperature sensor is also used to control the evaporative emission carbon canister purge valve, idle air control valve, etc. in gasoline engines. Once the water temperature sensor is damaged, the engine will malfunction and fail. Usually, the failure of the water temperature sensor will indirectly lead to the malfunction of fuel injection control and air intake control, which will lead to excessive emission of pollutants, and also cause problems such as diffic...

AI Technical Summary

Problems solved by technology

Usually, the failure of the water temperature sensor will indirectly lead to the failure of fuel injection control and air intake control, which will lead to excessive emission of pollutants, and also cause problems such as difficulty in starting or unstable idle speed.

[0003] The diagnosis method of the existing engine water temperature sensor is: judge the relationship between the time when the water temperature of the engine water temperature sensor rises to the target value and the ideal temperature rise time, if the time for the water temperature to rise to the target value is greater than the ideal temperature rise time, the engine water temperature sensor exists Malfunction, the measured water temperature is not an accurate and reliable indication of the actual temperature of the engine coolant

Images