LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2020 >> UX 200 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 44 (Hybrid Control System (Diagnostic Codes (5 Of 5) & Circuit Tests)) >> Hybrid Control System >> Cooling System [10/2018 - ] >> Procedure

Cooling System [10/2018 - ]: Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
  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

      HINT: 

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

    Result: 

    B 

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

    Result: 

    A 

    See step  2

  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

      HINT: 

      • 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.

    Result: 

    B 

    ADD HV COOLANT 

    Result: 

    C 

    INSPECT FOR COOLANT LEAK AND ADD COOLANT 

    Result: 

    A 

    See step  3

  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

    Result: 

    NG 

    REPAIR OR REPLACE COOLANT HOSE 

    Result: 

    OK 

    See step  4

  4. PERFORM ACTIVE TEST USING TECHSTREAM (CONTROL THE ENGINE COOLING FAN DUTY RATIO) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Enter the following menus: Powertrain / Engine / 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

      Techstream Operation Fan Operation
      30 - 100% Cooling fan operates
      0% Cooling fan stops

      Result

      Result Proceed to
      Cooling fan operate A
      Cooling fan does not operate B
      Cooling fan do not stop
    5. Turn the power switch off.

    Result: 

    B 

    CHECK COOLING FAN SYSTEM. Refer to  Cooling Fan Circuit [10/2018 - ] 

    Result: 

    A 

    See step  5

  5. PERFORM ACTIVE TEST USING TECHSTREAM (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.

    HINT: 

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

    1. Connect the Techstream 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 Techstream, perform the Active Test "Activate the Inverter Water Pump" and check the value of the Data List item "Inverter Water Pump Revolution".

      OK

      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG)
      During Active Test      		 3176 to 8617 rpm

      HINT: 

      • 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 lower than 200 rpm.
    6. Turn the power switch off.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  6

  6. READ VALUE USING TECHSTREAM (DATA LIST) 
    1. Connect the Techstream 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 Calculated Temperature, Motor Inverter Temperature.

      Powertrain > Hybrid Control > Data List 

      Tester Display
      Generator Inverter Calculated Temperature
      Motor Inverter Temperature
      Boosting Converter Temperature (Upper)
      Boosting Converter Temperature (Lower)
      Inverter Coolant Water Temperature
    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

      HINT: 

      The lower limit temperature that can be displayed for "Generator Inverter Calculated 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 Techstream may be lower than the others, but this is not a malfunction.

    5. Turn the power switch off.

    Result: 

    B 

    REPLACE INVERTER WITH CONVERTER ASSEMBLY. Refer to  REMOVAL [10/2018 - 07/2022]  Refer to  REMOVAL [07/2022 - ] 

    Result: 

    A 

    See step  7

  7. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING) 
    1. Connect the Techstream 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 Techstream.
    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

      HINT: 

      • 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.

    Result: 

    A 

    COOLING SYSTEM NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC) 

    Result: 

    B 

    REPLACE HV COOLANT. Refer to  REPLACEMENT [10/2018 - ] 

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

    Refer to PROCEDURE - Step 1

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    CONNECT SECURELY 

    Result: 

    OK 

    See step  9

  9. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WATER PUMP ASSEMBLY CONNECTOR) 
    1. Check the connector connections and contact pressure of the relevant terminals for the inverter water pump assembly connector.

      Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE [10/2018 - ]

      GTY779463Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      OK

      The connector is connected securely, the terminals are not deformed or corroded and there are no contact problems.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    CONNECT SECURELY 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WATER PUMP ASSEMBLY) 
    1. Disconnect the A46 hybrid vehicle control ECU connector.
    2. Disconnect the A3 inverter water pump assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Switch Condition Specified Condition
      A46-34 (IWP) - A3-3 (SWP) Power switch off Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Switch Condition Specified Condition
      A46-34 (IWP) or A3-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher
      GTY805850Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    4. Reconnect the A3 inverter water pump assembly connector.
    5. Reconnect the A46 hybrid vehicle control ECU connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  11

  11. READ VALUE USING TECHSTREAM (INVERTER WATER PUMP REVOLUTION) 
    NOTE:

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

    HINT: 

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

    1. Connect the Techstream to the DLC3.
    2. Remove the INV W/PMP fuse from No. 1 engine room relay block.
      GTY796160Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 1 Engine Room Relay Block
      *2 INV W/PMP Fuse
    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 Techstream, read the Data List.

      Powertrain > Motor Generator > Data List 

      Tester Display
      Inverter Water Pump Revolution

      Result

      Tester Display Switch 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

    Result: 

    NG 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [10/2018 - 07/2022]  Refer to  REMOVAL [07/2022 - ] 

    Result: 

    OK 

    See step  12

  12. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WATER PUMP ASSEMBLY) 
    1. Disconnect the A46 hybrid vehicle control ECU connector.
    2. Remove the INV W/PMP relay from the No. 1 engine room relay block.
    3. Connect terminals 3 and 5 of the INV W/PMP relay holder.
      GTY796487Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 1 Engine Room Relay Block
      *2 INV W/PMP Relay

      HINT: 

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

    4. Measure the voltage according to the value(s) in the table below.
      GTY800459Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Hybrid Vehicle Control ECU)      		 *b Front view of wire harness connector
      (to Hybrid Vehicle Control ECU)

      Standard Voltage

      Tester Connection Condition Specified Condition
      A46-34 (IWP) - F59-3 (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 A46 hybrid vehicle control ECU connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE INVERTER WATER PUMP ASSEMBLY. Refer to  REMOVAL [10/2018 - ] 

    Result: 

    OK 

    See step  13

  13. CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM) 
    1. Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.
    2. Turn the power switch on (IG).
    3. While turning the power switch on (IG), check the waveform between the hybrid vehicle control ECU terminals.
      GTY780605Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Hybrid Vehicle Control ECU)      		 - -
      Item Content
      Terminal A46-34 (IWP) - F59-3 (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

    Result: 

    NG 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [10/2018 - 07/2022]  Refer to  REMOVAL [07/2022 - ] 

    Result: 

    OK 

    See step  14

  14. REPLACE INVERTER WATER PUMP ASSEMBLY 

    Refer to REMOVAL [10/2018 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  15

  15. ADD HV COOLANT AND PERFORM AIR BLEEDING 
    1. After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

      Refer to PROCEDURE - Step 3

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

scientia non olet · About LEMON Manuals