Engine Thermostat Fault Diagnosis Using Blower Operation Feedback
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Solution Overview
Problem
Existing methods for diagnosing thermostat faults in engine cooling systems often lead to misdiagnosis due to the influence of blower operation, resulting in reduced thermal efficiency and increased fuel consumption.
Innovation Solution
A method and system that monitor the blower motor operation and diagnose thermostat faults by calculating the accumulated blower operating amount and comparing it with a set operating amount, while also considering coolant temperature and blower RPM, to accurately determine thermostat performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing thermostat fault diagnosis logic is used without considering blower operation, then the diagnosis process is simple, but misdiagnosis occurs when blower is used because coolant temperature decreases due to heat exchange
Solution Approach 1:
The diagnostic module monitors blower operation status and uses this feedback information to adjust the thermostat fault diagnosis logic. When the blower is detected to be operating, the system suppresses thermostat fault diagnosis to avoid misdiagnosis, while enabling it when the blower is not operating.
Solution Approach 2:
The diagnosis system dynamically adjusts its behavior based on real-time blower operation status. The thermostat fault diagnosis is conditionally enabled or suppressed depending on whether the blower is currently operating, making the diagnostic process adaptive rather than static.
2Reliability
If thermostat fault diagnosis is performed without monitoring blower operation, then the diagnostic module is simple, but thermal efficiency is reduced due to misdiagnosis leading to incorrect thermostat control
Solution Approach 1:
The system uses feedback from blower operation monitoring to prevent incorrect thermostat control actions. By detecting when the blower is operating, the system avoids suppressing the thermostat unnecessarily, ensuring the thermostat maintains proper engine temperature control only when appropriate.
Solution Approach 2:
The diagnostic system automatically determines whether thermostat fault diagnosis should be performed based on blower operation status, without requiring external intervention. The system self-adjusts its diagnostic behavior to prevent misdiagnosis and maintain optimal engine thermal efficiency.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Prevents misdiagnosis of thermostat faults by accurately assessing blower performance, thereby maintaining engine thermal efficiency and reducing fuel consumption.
Implementation Method 1
a blower motor configured to operate a blower which supplies outside air to the evaporator
Implementation Method 2
a heater core installed at a rear end of an evaporator of a heating and cooling path
Implementation Method 3
a heater core installed at a rear end of an evaporator of a heating and cooling path
Implementation Method 4
when a temperature of coolant of the engine rises and exceeds a target regulating temperature, the thermostat becomes in an open state
Data Source
AI summary
A method diagnoses a thermostat of an engine cooling system, where the thermostat provided at a heater core installed at a rear end of an evaporator of a heating and cooling path and at an engine coolant path formed to circulate coolant through an engine. The method includes receiving, by a diagnostic module, an operating current of a blower motor configured to operate a blower which supplies outside air to the evaporator; calculating, by the diagnostic module, an accumulated blower operating amount for a certain period of time using the operating current of the blower motor; and comparing, by the diagnostic module, the accumulated blower operating amount with a set operating amount. The method can prevent misdiagnosis of the thermostat by monitoring the blower motor to diagnose whether a fault occurs in the thermostat.