AIR CONDITIONING SYSTEM Compressor Operates but Cooling Effectiveness is Poor (High Pressure Reduction Not Performed)

PROCEDURE


  1. PERFORM MIDDLE DIFFERENTIAL PRESSURE VALVE STATE CHECK


    1. Perform the middle differential pressure valve state check.

      Click here

      OK
      Middle differential pressure valve state check is successful.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 AIR CONDITIONING ACCESSORY ASSEMBLY Click here

    OK

  2. PERFORM ACTIVE TEST USING GTS (COOLING ELECTRIC EXPANSION VALVE)


    1. Set the vehicle so that the following conditions are met.*

      Measurement Condition
      Item Condition
      Temperature setting MAX COLD
      Recirculation/fresh switch RECIRCULATION
      Blower speed HI
      Air outlet damper position FACE
      Interior temperature 25 to 35°C (77 to 95°F)
      A/C switch ON

    2. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    3. Perform the Active Test according to the display on the GTS.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Cooling Electric Expansion Valve Electric expansion valve (cooling)

      Min.: 0%

      Max.: 100%

      Perform this test with the following conditions met:


      • Active Test set to between 20 and 38%

      • Blower speed: HI

      • Driver side set temperature: MAX HOT

      • Ambient temperature: -10°C (14°F) or more

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Cooling Electric Expansion Valve

    4. With the measurement conditions* met, according to the display on the GTS, increase the value of Cooling Electric Expansion Valve by 15% and read the Data List.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Evaporator Fin Thermistor Evaporator temperature sensor

      Min.: -29.70°C (-21.46°F)

      Max.: 59.55°C (139.19°F)

      		 Actual evaporator temperature displayed -
      Regulator Pressure Sensor Air conditioner pressure sensor

      Min.: -0.4566 MPaG

      Max.: 3.2943 MPaG

      		 Actual refrigerant pressure displayed -
      Cooling Electric Expansion Valve Target Position Electric expansion valve (cooling)

      Min.: 0.00%

      Max.: 100.00%

      		 Electric expansion valve (cooling) target position displayed -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Evaporator Fin Thermistor
      Regulator Pressure Sensor
      Cooling Electric Expansion Valve Target Position
      OK
      The value of Evaporator Fin Thermistor increases by 3°C (37°F).
      Result
      Proceed to
      OK
      NG

    NG

    CHECK ELECTRIC EXPANSION VALVE (COOLING) Click here

    OK

  3. READ VALUE USING GTS (EVAPORATOR FIN THERMISTOR)


    1. According to the display on the GTS, decrease the value of Cooling Electric Expansion Valve by 15% and read the Data List.

    2. Enter the following menus: Body Electrical / Air Conditioner / Data List.

    3. Read the Data List according to the display on the GTS.


      Body Electrical > Air Conditioner > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Evaporator Fin Thermistor Evaporator temperature sensor

      Min.: -29.70°C

      (-21.46°F)

      Max.: 59.55°C

      (139.19°F)

      		 Actual evaporator temperature displayed -

      Body Electrical > Air Conditioner > Data List
      Tester Display
      Evaporator Fin Thermistor
      OK
      The value of Evaporator Fin Thermistor decreases by 3°C (37°F).
      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 8 Click here

    OK

  4. INSPECT LOW PRESSURE MAGNETIC VALVE


    1. Turn the power switch on (READY).

    2. Push the AUTO switch to operate the air conditioning system.

    3. Turn the power switch off and wait for 2 minutes.

    4. Remove the low pressure magnetic valve.

      Click here

    5. Inspect the low pressure magnetic valve.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE LOW PRESSURE MAGNETIC VALVE Click here

    OK

  5. LOW PRESSURE MAGNETIC VALVE (POWER SOURCE CIRCUIT)


    1. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    2. Perform the Active Test according to the display on the GTS.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Low Pressure Magnetic Valve Low pressure magnetic valve OFF or ON -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Low Pressure Magnetic Valve
    3. A003LC3C01
      *a

      Component without harness connected

      (Low Pressure Magnetic Valve)

      Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A44-2 (VB) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (LOW PRESSURE MAGNETIC VALVE - HEAT PUMP ECU ASSEMBLY)


    1. Disconnect the A42 heat pump ECU assembly connector.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A44-1 (HPMV) - A42-23 (LPMV) Always Below 1 Ω
      A44-1 (HPMV) or A42-23 (LPMV) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK VALVE TO CONNECTOR TUBE


    1. Remove the valve to connector tube.

      Click here

    2. Apply compressed air to the inlet port and then outlet port of the valve to connector tube.

      OK
      Air flows out of the outlet port when applied to the inlet port but not out of the inlet port when applied to the outlet port.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE EVAPORATOR PRESSURE REGULATOR Click here

    NG

    REPLACE VALVE TO CONNECTOR TUBE Click here

  8. CHECK ELECTRIC EXPANSION VALVE (COOLING)


    1. Inspect the electric expansion valve (cooling).

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    NG

    REPLACE ELECTRIC EXPANSION VALVE (COOLING) Click here