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
Grille blockage, coolant amount, coolant hoses, HV radiator fan Check for overheating due to hybrid cooling system malfunction.
Inverter coolant temperature sensor (built-in inverter) Check for temperature sensor malfunction.
Coolant freezing check Check freeze frame values to determine whether the hybrid coolant was frozen when the DTC was stored.
Related Data List
Data List

  • Inverter Coolant Water Temperature

  • Motor Inverter Temperature

  • Generator Inverter Temperature

  • Boosting Converter Temperature (Upper)

  • Boosting Converter Temperature (Lower)

  • Ambient Temperature

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.


  1. for LHD:

    B004XKOC02
    *A for 2WD - -
    *1 Inverter Water Pump Assembly *2 Inverter Reserve Tank Assembly
    *3 Inverter with Converter Assembly *4 Radiator Assembly (HV)
    *5 Hybrid Vehicle Transmission Assembly - -
    B004XGIC01
    *A for AWD - -
    *1 Inverter Water Pump Assembly *2 Inverter Reserve Tank Assembly
    *3 Inverter with Converter Assembly *4 Radiator Assembly (HV)
    *5 Hybrid Vehicle Transmission Assembly - -

  2. for RHD:

    B004S74C02
    *A for 2WD - -
    *1 Inverter Water Pump Assembly *2 Inverter Reserve Tank Assembly
    *3 Inverter with Converter Assembly *4 Radiator Assembly (HV)
    *5 Hybrid Vehicle Transmission Assembly - -
    B004UYPC02
    *A for AWD - -
    *1 Inverter Water Pump Assembly *2 Inverter Reserve Tank Assembly
    *3 Inverter with Converter Assembly *4 Radiator Assembly (HV)
    *5 Hybrid Vehicle Transmission Assembly - -

WIRING DIAGRAM

B004YB9E06

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:


  • B004STG

    Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.


    • Inspecting the high-voltage system

    • Disconnecting the low voltage connector of the inverter with converter assembly

    • Disconnecting the low voltage connector of the HV battery

  • B004Y5N

    To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.

  • B004SX1

    After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • B004W3JC06
    *a Without waiting for 10 minutes

    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.

  • Make sure to insulate the high-voltage connectors and terminals of the HV battery with insulating tape after removing it.

    If the HV battery stored without insulating the connectors and terminals, electric shock or fire may result.

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
      Result Proceed to
      Not blocked. A
      Is/was blocked. B

      Tech Tips

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


    B

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

    A

  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 Active Tests "Activate the Inverter Water Pump" (Hybrid Control System) and "Control the Electric Cooling Fan" (Engine Control system) and make sure that there are no malfunctions.

      • If there are signs of coolant leakage around the connecting parts of a hose and the inverter with converter assembly, replace the hose with a new one.


    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 ENGINE COOLING FAN DUTY RATIO)


    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 Engine Cooling Fan Duty Ratio.


      Powertrain > Engine > Active Test
      Tester Display
      Control the Engine Cooling Fan Duty Ratio

    4. Perform the "Control the Engine Cooling Fan Duty Ratio" Active Test.

      OK
      GTS Operation Fan Operation
      30 - 100% Cooling fan operates
      0% Cooling fan stops
      Result
      Result Proceed to
      Cooling fan operate (w/ Grille shutter) A
      Cooling fan operate (w/o Grille shutter) B
      Cooling fan does not operate C
      Cooling fan do not stop

    5. Turn the power switch off.


    B

    GO TO STEP 6 Click here

    C

    CHECK COOLING FAN SYSTEM Click here

    A

  5. PERFORM ACTIVE TEST USING GTS (GRILLE SHUTTER OPERATION)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Body Electrical / Grill Shutter / Utility / Grill Shutter Control Mode Switching.

    4. According to the display on the GTS, change the grille shutter control mode from normal mode to maintenance mode.


      Body Electrical > Grill Shutter > Utility
      Tester Display
      Grill Shutter Control Mode Switching

    5. Enter the following menus: Body Electrical / Grill Shutter / Active Test / Shutter Closing Operation Lock Detection / Data List / Shutter Operation Lock Detection Result for Active Test.

    6. According to the display on the GTS, perform the Active Test and read the value of Data List item Shutter Operation Lock Detection Result for Active Test.


      Body Electrical > Grill Shutter > Active Test
      Active Test Display
      Shutter Closing Operation Lock Detection
      Data List Display
      Shutter Operation Lock Detection Result for Active Test
      OK
      "Normal" is displayed.

    7. Enter the following menus: Body Electrical / Grill Shutter / Active Test / Shutter Opening Operation Lock Detection / Data List / Shutter Operation Lock Detection Result for Active Test.

    8. According to the display on the GTS, perform the Active Test and read the value of Data List item Shutter Operation Lock Detection Result for Active Test.


      Body Electrical > Grill Shutter > Active Test
      Active Test Display
      Shutter Opening Operation Lock Detection
      Data List Display
      Shutter Operation Lock Detection Result for Active Test
      OK
      "Normal" is displayed.

      Tech Tips

      When the value of Data List item Shutter Operation Lock Detection Result for Active Test is "Normal", it can be determined that the grille shutter system is normal.

    9. Enter the following menus: Body Electrical / Grill Shutter / Utility / Grill Shutter Control Mode Switching.

    10. According to the display on the GTS, change the grille shutter control mode from maintenance mode to normal mode.


      Body Electrical > Grill Shutter > Utility
      Tester Display
      Grill Shutter Control Mode Switching

    11. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK GRILLE SHUTTER SYSTEM Click here

    OK

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

    Note


    • Make sure that the HV coolant level is above the low line of the inverter reserve tank.

    • 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
      Active Test Display
      Activate the Inverter Water Pump
      Data List Display
      Inverter Water Pump Revolution

    4. Select the Data List item "Inverter Water Pump Revolution".

    5. According to the display on the GTS, perform the Active Test "Activate the Inverter Water Pump" and check the value of the Data List item "Inverter Water Pump Revolution".

      Result
      Tester Display Specified Condition
      Inverter Water Pump Revolution 3200 to 8600 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 Water Pump Revolution" displays a value 200 rpm or less.

    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

  7. READ VALUE USING GTS (DATA LIST)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (READY) and wait for 1 minute with the engine stopped.

    3. Enter the following menus: Powertrain / Hybrid Control / Data List / Boosting Converter Temperature (Upper), Boosting Converter Temperature (Lower), Inverter Coolant Water Temperature, Generator Inverter Temperature, Motor Inverter Temperature.


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter Coolant Water Temperature
      Generator Inverter Temperature
      Motor Inverter Temperature
      Boosting Converter Temperature (Upper)
      Boosting Converter Temperature (Lower)

    4. Read the Data List with the engine stopped.

      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 "Generator Inverter Temperature", "Motor Inverter Temperature", "Boosting Converter Temperature (Upper)" and "Boosting Converter Temperature (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.

    5. Turn the power switch off.


    B

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

    A

  8. 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.


      Powertrain > Hybrid Control > Trouble Codes

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

    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

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

    Result
    Proceed to
    OK
    NG

    1. B004W01C01
      *A for LHD
      *B for RHD

      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.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

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


    1. B004XDU

      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, the terminals are not deformed or corroded and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the A77 hybrid vehicle control ECU assembly connector.

    2. Disconnect the A84 inverter water pump assembly connector.

    3. B004SQUC11
      *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)

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A77-9 (IWP) - A84-3 (SWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A77-9 (IWP) or A84-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A84 inverter water pump assembly connector.

    5. Reconnect the A77 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. READ VALUE USING GTS (INVERTER WATER PUMP 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. B004W98C02
      *1 No. 1 Engine Room Relay Block
      *2 INV W/PMP Fuse

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

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / Motor Generator Control / Data List / Inverter Water Pump Revolution.

    5. According to the display on the GTS, read the Data List.


      Powertrain > Motor Generator > Data List
      Tester Display
      Inverter Water Pump Revolution
      Result
      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG) 200 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

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


    1. Disconnect the A77 hybrid vehicle control ECU assembly connector.

    2. Remove the INV W/PMP relay from the No. 1 engine room relay block.

    3. B004XTVC02
      *1 No. 1 Engine Room Relay Block
      *2 INV W/PMP Relay

      Connect terminals 3 and 5 of the INV W/PMP relay holder.

      Tech Tips

      Make a short circuit between terminals 3 and 5 to supply +B voltage to the inverter water pump.

    4. B004YO1C55
      *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
      A77-9 (IWP) - G92-6 (E1)

      INV W/PMP relay holder terminals 3 and 5 connected

      Power switch off

      		 11 to 14 V

      Note

      Make sure to check for and clear DTCs after performing this inspection.

    5. Install the INV W/PMP relay.

    6. Reconnect the A77 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  14. 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. B004U4TC22
      *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.

      Tester Connection Condition Equipment Setting
      A77-9 (IWP) - G92-6 (E1) Power switch on (IG) 5 V/DIV., 50 ms./DIV.
      OK
      Waveform duty ratio is between 3% and 9%.

    4. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here