HYBRID CONTROL SYSTEM, Diagnostic DTC:P0C73-776

DTC Code DTC Name
P0C73-776 Motor Electronics Coolant Pump "A" Control Performance

DESCRIPTION

The inverter water pump assembly transmits rotation speed information to the power management control ECU (HV CPU). The power management control ECU (HV CPU) monitors the rotation speed and detects malfunctions.

DTC No. INF Code DTC Detection Condition Trouble Area
P0C73 776

The inverter water pump assembly revolution speed is abnormally high or low (or stop) for 1 minute or more.

Or the inverter water pump assembly stops intermittently after abnormal revolution speed is detected.

(1 trip detection logic)

  • Inverter cooling system

  • Wire harness or connector

  • Inverter water pump assembly

  • Power management control ECU
Related Data List
DTC No. Data List
P0C73-776

  • Inverter W/P Revolution

  • W/P Run Control Duty*1

  • Ready Signal

Related Active Test
DTC No. Data List
P0C73-776 Activate the Water Pump*2

WIRING DIAGRAM

A004YKNE26

CAUTION / NOTICE / HINT

Note


  • In the case of a coolant leak, the inverter water pump assembly activates a fail-safe function. If the inverter water pump assembly is not the cause of the coolant leak, it is not necessary to replace it.

  • If this vehicle is jump started, etc. and excessive voltage is applied to the auxiliary battery, the inverter water pump assembly may suspend control as a fail-safe function and the power management control ECU may store this DTC.

    (When the auxiliary battery voltage returns to normal, the inverter water pump assembly will resume normal operation. In this case, it is not necessary to replace the inverter water pump assembly.)

  • If air enters the system while bleeding air and the inverter water pump assembly revolution speed becomes abnormally high, the inverter water pump assembly may suspend control as a fail-safe function and the power management control ECU may store this DTC.

    (When air bleeding is complete, the inverter water pump assembly will resume normal operation. In this case, it is not necessary to replace the inverter water pump assembly.)

Tech Tips

After the repair, clear the DTCs and perform the following procedure to check that DTCs are not output.


  1. Turn the power switch on (READY) and wait for 2 minutes or more.

PROCEDURE


  1. CHECK QUANTITY OF HV COOLANT


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

    2. Check for coolant leaks.

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

      Tech Tips

      After repairing the coolant leaks and adding coolant, perform the "Activate the 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.


    B

    ADD HV COOLANT

    C

    INSPECT FOR COOLANT LEAK

    A

  2. CHECK COOLANT HOSE


    1. Check if the hoses of the cooling system are kinked or clogged.


    NG

    CORRECT THE PROBLEM

    OK

  3. CHECK INVERTER WATER PUMP ASSEMBLY

    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.

    • When the inverter water pump assembly serial communication line (SWP - IWP) is open or its connection is faulty, the inverter water pump assembly is operated forcibly.


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Data List.

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

    5. Read the Data List.

      Result
      Tester Display Specified Condition
      Inverter W/P Revolution 625 rpm or less

      Tech Tips

      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.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) Click here

    OK

  4. CLEAR DTC


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / DTC.

    4. Clear DTCs and freeze frame data.

    5. Turn the power switch off.


    NEXT

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (ACTIVATE THE 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 intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

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

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

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

      Result
      Tester Display Specified Condition
      Inverter W/P Revolution 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.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) Click here

    OK

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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Read the freeze frame data Ambient Temperature using the intelligent tester.

    4. Check if the freeze frame data Ambient Temperature is below freezing.

      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 assembly, the coolant temperature in the inverter with converter assembly rises because the HV coolant cannot circulate. As a result, a DTC may be set.

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

      • If a DTC is set due to freezing of HV coolant, the problem cannot be reproduced. Judge whether freezing of HV coolant occurred according to the freeze point of the HV coolant, HV coolant change history and ambient temperature when the DTC was set.

    5. Turn the power switch off.


    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    B

    REPLACE HV COOLANT Click here

  7. CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR)


    1. Check the connections of the power management control ECU connectors.

      B001M45E01
      Text in Illustration
      *A for LHD *B for RHD
      OK
      The connectors are connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

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


    1. A004XMV

      Check the connection of the inverter water pump assembly connector.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

  9. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect connector A19 from the power management control ECU.

    2. Disconnect connector e1 from the inverter water pump assembly.

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

      A004XTKE02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 *b

      Front view of wire harness connector

      (to Inverter Water Pump Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      e1-3 (SWP) - A19-13 (IWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      e1-3 (SWP) or A19-13 (IWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Connect the power management control ECU connector.

    5. Connect the inverter water pump assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. READ VALUE USING INTELLIGENT TESTER (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 intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / ECU Data List.

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

    5. Disconnect connector e1 from the inverter water pump assembly.

    6. Read the Data List.

      Result
      Tester Display Specified Condition
      Inverter W/P Revolution 125 rpm or less

    7. Connect the inverter water pump assembly connector.

    8. Turn the power switch off.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INVERTER WATER PUMP ASSEMBLY)


    1. Disconnect connector A19 from the power management control ECU.

    2. Turn the power switch on (IG).

    3. A004XA3E02
      Text in Illustration
      *a

      Rear view of wire harness connector

      (to Power Management Control ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A19-13 (IWP) - H3-6 (E1) Power switch on (IG) 11 to 14 V

      Note

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

    4. Turn the power switch off.

    5. Connect the power management control ECU connector.


    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  12. CHECK POWER MANAGEMENT CONTROL ECU


    1. Turn the power switch on (IG).

    2. A004YR3E02
      Text in Illustration
      *a

      Component with Harness Connected

      (Power Management Control ECU)

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

      Item Content
      Terminal A19-13 (IWP) - H3-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Power switch on (IG)
      OK
      Waveform duty ratio is between 3% and 9%.

    3. Turn the power switch off.


    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here