This invention provides a method for automatically adding
coolant using a vehicle controller, comprising: S1: A conduction module sends a conduction command to control the water injection three-way valve A-B to be open and port C to be closed; S2: A
liquid injection module sends a
liquid injection command to control the motor water pump to run at
low speed, drawing
coolant so that
coolant flows in through port A of the water injection three-way valve; S3: When the coolant in the motor
expansion tank reaches a first liquid level value, a
liquid level sensor feeds back first information to the liquid level control module of the
vehicle control unit. When the liquid level control module receives the first information, it sends a first command. The battery water pump receives the first command and starts running at
low speed; S4: When the coolant in the motor
expansion tank reaches a first liquid level value, a
liquid level sensor feeds back first information to the liquid level control module of the
vehicle control unit. When the liquid level control module receives the first information, it sends a first command. When the battery water pump receives the first command, it starts running at
low speed; S4: When the motor
expansion tank reaches a first liquid level value... When the coolant reaches the second level value, the
level sensor feeds back the second information to the level control module. Upon receiving the second information, the level control module sends a second command to the water injection three-way valve. The water injection three-way valve opens C-B and closes A according to the second command. S5: The air venting module sends a venting command. The motor water pump and battery water pump run at high speed for time period T1 according to the venting command, and then close and stand for time period T2. S6: The detection module sends a detection command. The
level sensor checks whether the coolant in the motor expansion tank has reached the required level according to the detection command. If not, it feeds back to the activation module and repeats steps S1-S5. If yes, the filling ends.