Inspection Method
1)Check the Pressure of Air Conditioner Refrigerant
（1）First,connect the quick connector of high pressure and low pressure respectively with the high pressure and low pressure fast interface of air conditioner cooling system(as shown in Fig.3.63)
（2）Tighten the knob above the quick connector clockwise,at this moment,the pressure on the high pressure gauge is the static pressure of high pressure side of air conditioning system and the pressure on the low pressure gauge refers to the static pressure of low pressure side of air conditioning system.
（3）Start the air conditioner,keep the rotation speed of the engine around 2000 and turn the blower to the maximum,and adjust the temperature to the lowest,then lastly,test the high and low pressure of air conditioner with air conditioner pressure gauge.
Fig.3.63 Connection of Air Conditioner Pressure Gauge
Note:
Before connecting with the air conditioner pressure gauge,make sure that high and low temperature hand valve is closed.
Standard value of air conditioner pressure:
High pressure:2.4-2.8 MPa；
Low pressure:0.21-0.25 MPa
2)Check the Circuit of Air Conditioner Compressor
The circuit diagram of CX70 compressor is shown in Fig.3.64.
Fig.3.64 Compressor Circuit Diagram
（1）Inspection of Power Circuit
Check whether the relay and the fuse line of compressor is open circuit or not and whether the fuse is burnt down or not.The fuse position is shown in Fig.3.65.
Fig.3.65 Fuse of Air Conditioner
（2）Resistance Inspection of Electromagnetic Clutch
As shown in Fig.3.66,use the red probe of universal meter to connect with pin 1 of compressor and black probe to be grounded.The measured resistance value is around 3 Ω,and if the value is less than 1 Ω,then it is short circuit.
Fig.3.66 Compressor Pin
3)Inspection of Blower Circuit
As shown in Fig.3.67,do the following inspections.
(https://www.daowen.com)
Fig.3.67 Blower Control Circuit
(1)Inspection of Power Circuit.
Check whether the relay and the fuse line of blower is open circuit or not and whether the fuse is burnt down or not.When the engine is started,turn on the ignition key and then the power source voltage should be storage battery voltage and the grounding voltage should be 0 V.If not,check the power source.
(2)Inspection of blower speed regulation module.
As shown in Fig.3.68 Blower Speed Regulation Module Picture and Its Connector Picture.
Fig.3.68 Blower Speed Regulation Module Picture and Its Connector Picture
Check the wind volume regulation control signal voltage of speed regulation module(brown/green wire),and with the wind speed increase from gear 1 to 8,the voltage decreases from around 6.8 V to 0.35 V gradually,and the feedback signal voltage of speed regulation module(blue wire)increases from 2.4 V to about 7.9 V.If the voltage of one signal wire keeps unchanged,check whether the wire harness is broken or not,whether the air conditioner controller connector is loose or not.If both are OK,replace speed regulation module.
4)Inspection of Air Conditioner Actuator Motor Circuit
CX70 motor control mode adopts DC motor+position sensor.The air conditioner controller controls the motion of the motor,which makes the mixed door move,and meanwhile,moves the mobile contact point of position sensor,and then the air conditioner controller confirms the position of each wind door through the changes of the signal.
（1）Inspection of power circuit.
As shown in Fig.3.69,check the pin 30(power source 5 V)and pin 15(grounding)of air conditioner controller respectively.If abnormal,check every power source and grounding of air conditioner controller.
Fig.3.69 Circuit of Air Conditioner Actuator
Fig.3.70 Air Conditioning System Servo Motors
(2)inspection of servo motor feedback voltage.
①Inspection of mode control servo motor feedback voltage:Turn the mode control knob,and check the pin 29 of air conditioner control module.And the voltage value should be as the inspection standard shown in Table 3.11.
Table 3.11 Feedback Voltage of Mode Control Servo Motor
②Inspection of temperature control servo motor feedback voltage:Turn the temperature control knob,and check the pin 3 of air conditioner control module.And the voltage value should be as the inspection standard shown in Table 3.12
Table 3.12 Feedback Voltage of Temperature Control Servo Motor
③Inspection of internal-external circulation control servo motor feedback voltage:Press the internal-external circulation control button,and check the pin 18 of air conditioner control module.And the voltage value should be as the inspection standard shown in Table 3.13.
Table 3.13 Feedback Voltage of Internal-External Circulation Control Servo Motor
