HYBRID CONTROL SYSTEM Cooling System

DESCRIPTION

The cause of the malfunction may be the cooling system.

Check whether the grille is blocked, whether coolant is leaking, the HV radiator fan operating condition and whether coolant has frozen.

Related Parts Check
Area Inspection Step
Grille blockage, coolant amount, coolant hoses, HV radiator fan Check for overheating due to hybrid cooling system malfunction. 1, 2, 3, 4
Inverter coolant temperature sensor (built-in inverter) Check for temperature sensor malfunction. 5
Coolant freezing check Check freeze frame values to determine whether the hybrid coolant was frozen when the DTC was stored. 6

SYSTEM DESCRIPTION

The inverter converts the high-voltage direct current of the HV battery into alternating current for the generator (MG1) and motor (MG2). The inverter generates heat during the conversion process. Therefore, the inverter is cooled by a special cooling system consisting of the inverter water pump assembly, the cooling fan, and a radiator. This cooling system is independent of the engine cooling system. The hybrid vehicle control ECU assembly monitors the inverter water pump assembly, cooling fan and cooling system, and detects malfunctions.

B004E9BC01
*A for LHD *B for RHD
*1 Inverter Water Pump Assembly *2 Inverter Reserve Tank Assembly
*3 Inverter with Converter Assembly *4 Radiator Assembly (HV)
*5 Hybrid Vehicle Transmission Assembly - -

CAUTION / NOTICE / HINT

This step is referenced from the procedures for each DTC.

If the inspection results below are normal, perform the next procedure for the referenced DTC.

CAUTION:


  • Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

    Click here

    Tech Tips

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

Note

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

Click here

PROCEDURE


  1. CHECK VEHICLE CONDITION


    1. Make sure that the front side of the radiator grille is not blocked with anything.

    2. Ask the customer if the front side of the radiator grille was blocked with anything.

      Result
      Proceed to
      Not blocked.
      Is/was blocked.

      Tech Tips

      If the radiator grille is blocked, the inverter coolant temperature will increase and this DTC may be stored.


    Is/was blocked.

    IF EQUIPPED, EXPLAIN TO CUSTOMER THAT OPTIONAL COMPONENTS WILL BE REMOVED

    Not blocked.

  2. CHECK QUANTITY OF HV COOLANT


    1. Check the HV coolant level in the inverter reserve tank.

    2. Check for HV coolant leaks.

      Result
      Result Proceed to
      No leaks are found and the HV coolant level in the inverter reserve tank assembly is above the low line. A
      No leaks are found and the HV coolant level in the inverter reserve tank assembly is below the low line. B
      HV coolant leaks are evident. C

      Tech Tips


      • After repairing the HV coolant leaks and adding coolant, perform the "Activate the (Inverter) Water Pump" Active Test (HV Active Test item) and the "Control the Electric Cooling Fan" Active Test (Engine Active Test item) and make sure that there are no malfunctions.

      • The inverter water pump assembly will not malfunction due to coolant leaks.


    B

    ADD HV COOLANT

    C

    INSPECT FOR COOLANT LEAK AND ADD COOLANT

    A

  3. CHECK COOLANT HOSE


    1. Check that the cooling system hoses are not kinked or clogged.

      OK
      The cooling system hoses are not kinked or clogged.
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE COOLANT HOSE

    OK

  4. PERFORM ACTIVE TEST USING GTS (CONTROL THE ELECTRIC COOLING FAN)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Engine and ECT / Active Test / Control the Electric Cooling Fan.

    4. Perform the "Control the Electric Cooling Fan" Active Test.


      Powertrain > Engine and ECT > Active Test
      Tester Display
      Control the Electric Cooling Fan
      OK
      The cooling fan rotates.

    5. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK COOLING FAN SYSTEM Click here

    OK

  5. PERFORM ACTIVE TEST USING GTS (ACTIVATE THE (INVERTER) WATER PUMP)

    Note

    Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

    Tech Tips

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Active Test / Activate the (Inverter) Water Pump.


      Powertrain > Hybrid Control > Active Test
      Tester Display
      Activate the (Inverter) Water Pump

    4. Select "Inverter W/P Revolution" in the Data List.


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter W/P Revolution

    5. While performing the "Activate the (Inverter) Water Pump" Active Test, check "Inverter W/P Revolution" in the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 2250 to 5625 rpm

      Tech Tips


      • Perform the Active Test with the inverter coolant temperature between -15 and 65°C (5 to 149°F).

      • When the inverter water pump assembly is not operating, the Data List item "Inverter W/P Revolution" displays a value lower than 625 rpm.

    6. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU ASSEMBLY CONNECTOR) Click here

    OK

  6. READ VALUE USING GTS (DATA LIST)


    1. Turn the power switch off and leave the vehicle for at least 1 hour.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / Hybrid Control / Data List / DC/DC Cnv Tmp (Upper), DC/DC Cnv Temp (Lower), Inverter Coolant Water Temperature, Inverter Temp-(MG1), Inverter Temp-(MG2).


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter Temp-(MG1)
      Inverter Temp-(MG2)
      Inverter Coolant Water Temperature
      DC/DC Cnv Temp (Upper)
      DC/DC Cnv Temp (Lower)

    5. Read the Data List.

      Result
      Result Proceed to
      Other than below. A
      "Inverter Coolant Water Temperature" value is higher than the displayed temperature of any other Data List item by 20°C (68°F) or more. B

      Tech Tips

      The lower limit temperature that can be displayed for "Inverter Temp- (MG1)", "Inverter Temp- (MG2)", "DC/CD Cnv Temp (Upper)" and "DC/DC Cnv Temp (Lower)" is 15°C (59°F). The lower limit temperature for "Inverter Coolant Water Temperature" is -40°C (-40°F). The "Inverter Coolant Water Temperature" value displayed on the GTS may be lower than the others, but this is not a malfunction.

    6. Turn the power switch off.


    B

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

    A

  7. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Read the freeze frame data item Ambient Temperature using the GTS.


      Powertrain > Hybrid Control > Trouble Codes

    5. Check if the freeze frame data item Ambient Temperature is below the freezing temperature of the HV coolant.

      Result
      Result Proceed to
      Ambient Temperature value is above freezing temperature of the HV coolant. A
      Ambient Temperature value is below freezing temperature of the HV coolant. B

      Tech Tips


      • HV coolant (SLLC) with a 30% concentration freezes at -15°C (5°F) and HV coolant (SLLC) with a 50% concentration freezes at -35°C (-31°F).

      • If the HV coolant freezes in the HV radiator or inverter water pump, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be stored.

      • A DTC is stored when the inverter water pump impeller cannot rotate due to freezing of the HV coolant.

      • If DTCs are output due to freezing of the LLC, the problem symptom cannot be reproduced. Check the LLC replacement history and whether the LLC was frozen based on the ambient temperature when the DTCs were stored.

    6. Turn the power switch off.


    A

    COOLING SYSTEM NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC)

    B

    REPLACE HV COOLANT Click here

  8. CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU ASSEMBLY CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. Check the connector connections and contact pressure of the relevant terminals for the hybrid vehicle control ECU assembly connectors.

      Click here

      OK
      The connectors are connected securely and there are no contact pressure problems.
      B004GK9C01
      *A for LHD *B for RHD
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  9. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR)


    1. B004EHT

      Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector.

      Click here

      OK
      The connector is connected securely and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  10. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect the A80 hybrid vehicle control ECU assembly connector.

    2. Disconnect the A12 inverter water pump assembly connector.

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

      B004G0WC32
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

      		 *b

      Front view of wire harness connector

      (to Inverter Water Pump Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A80-13 (IWP) - A12-3 (SWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A80-13 (IWP) or A12-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A12 inverter water pump assembly connector.

    5. Reconnect the A80 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. READ VALUE USING GTS (INVERTER W/P REVOLUTION)

    Note

    Be sure to perform the inspection with the auxiliary battery voltage at 11 V or more.

    Tech Tips

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. B004GH2C01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 INV W/PMP Fuse

      Remove the INV W/PMP fuse from No. 1 engine room relay block and No. 1 junction block assembly.

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / Hybrid Control / Data List / Inverter W/P Revolution.


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter W/P Revolution

    5. Read the Data List.

      Standard
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 125 rpm or less

    6. Turn the power switch off.

    7. Install the INV W/PMP fuse.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    OK

  12. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect the A80 hybrid vehicle control ECU assembly connector.

    2. Turn the power switch on (IG).

    3. B004GANC22
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A80-13 (IWP) - O141-6 (E1) Power switch on (IG) 11 to 14 V

      Note

      Turning the power switch on (IG) with the hybrid vehicle control ECU assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    4. Turn the power switch off.

    5. Reconnect the A80 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  13. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (CHECK WAVEFORM)


    1. Connect an oscilloscope between the hybrid vehicle control ECU assembly terminals specified in the table below.

    2. Turn the power switch on (IG).

    3. B004GD4C64
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

      While turning the power switch on (IG), check the waveform between the hybrid vehicle control ECU assembly terminals.

      Item Content
      Terminal A80-13 (IWP) - O141-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Power switch on (IG)
      OK
      Waveform duty ratio is between 3% and 9%.

    4. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    OK

  14. REPLACE INVERTER WATER PUMP ASSEMBLY

    Click here

    Result
    Proceed to
    NEXT

    NEXT

  15. ADD HV COOLANT AND PERFORM AIR BLEEDING


    1. After replacing the inverter water pump with motor assembly, add HV coolant and perform air bleeding.

      Click here

      Result
      Proceed to
      NEXT

    NEXT

    END