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 revolution information to the power management control ECU. The power management control ECU monitors the revolution and detects malfunctions.

DTC No. INF Code DTC Detection Condition Trouble Area
P0C73 776 A revolution or intermittent stop malfunction occurs in the inverter water pump assembly.

  • Inverter cooling system

  • Wire harness or connector

  • Inverter water pump assembly

  • Power management control ECU

WIRING DIAGRAM

A01UY2PE02
*a IGCT NO. 3
*b Inverter Water Pump Assembly
*c IGCT-MAIN
*d Power Management Control ECU

CAUTION / NOTICE / HINT

Tech Tips


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


    1. Turn the ignition switch to ON (READY) and wait for 2 minutes or more.

  • 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 self-protection function and store 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.)

PROCEDURE


  1. 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
      HV coolant leaks are not evident. HV coolant level is above the low line in the inverter reserve tank. A
      HV coolant leaks are not evident. HV coolant level is below the low line in the inverter reserve tank. B
      HV coolant leaks are evident. C

      Tech Tips

      After repairing the HV 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 Click here

    C

    INSPECT FOR HV COOLANT LEAK Click here

    A

  2. CHECK COOLANT HOSE


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


    NG

    CORRECT THE PROBLEM Click here

    OK

  3. 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. Turn the ignition switch to ON (IG).

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

    4. Read the Data List.

      Result
      GTS Display Switch Condition Specified Condition
      Inverter W/P Revolution Ignition switch ON (IG) 625 rpm or less

    5. Turn the ignition switch off.


    NG

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

    OK

  4. PERFORM ACTIVE TEST USING GTS (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 GTS to the DLC3.

    2. Turn the ignition switch to 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
      GTS Display Switch Condition Specified Condition
      Inverter W/P Revolution Ignition 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).

    6. Turn the ignition switch off.


    NG

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

    OK

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


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON (IG).

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

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

    5. 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 HV 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 set.

      • A DTC is set when the water pump 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.

    6. Turn the ignition switch off.


    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    B

    REPLACE HV COOLANT Click here

  6. ADD HV COOLANT


    1. Add HV coolant up to the high level in the reserve tank.


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  7. INSPECT FOR HV COOLANT LEAK


    1. Diagnose and repair the HV coolant leak.


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  8. CORRECT THE PROBLEM


    1. Correct the coolant hose.


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

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


    1. A01V0I0E01
      Text in Illustration
      *A for LHD
      *B for RHD

      Check the connector connections and contact pressure of the relevant terminals for the power management control ECU connectors Click here.

      OK
      The connectors are connected securely and there are no contact pressure problems.

    NG

    CONNECT SECURELY Click here

    OK

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


    1. A01UY5T

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

      OK
      The connectors are connected securely and there are no contact pressure problems.

    NG

    CONNECT SECURELY Click here

    OK

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


    1. Disconnect the power management control ECU connector.

    2. Disconnect the inverter water pump assembly connector.

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

      A01V0FUE02
      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
      A36-3 (SWP) - A26-13 (IWP) Ignition switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      A36-3 (SWP) or A26-13 (IWP) - Body ground and other terminals Ignition 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 Click here

    OK

  12. 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. Turn the ignition switch to ON (IG).

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

    4. Disconnect connector A36 from the inverter water pump assembly.

    5. Read the Data List.

      Result
      GTS Display Switch Condition Specified Condition
      Inverter W/P Revolution Ignition switch ON (IG) 125 rpm or less

    6. Turn the ignition switch off.

    7. Connect the inverter water pump assembly connector.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

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


    1. Disconnect the power management control ECU connector.

    2. Turn the ignition switch to ON (IG).

    3. A01UXVTE02
      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
      A26-13 (IWP) - F55-6 (E1) Ignition switch ON (IG) 11 to 14 V

      Note

      Turning the ignition switch to 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 ignition switch off.

    5. Connect the power management control ECU connector.


    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  14. CHECK POWER MANAGEMENT CONTROL ECU (CHECK WAVEFORM)


    1. Connect an oscilloscope between the power management control ECU terminals specified in the following table.

    2. Turn the ignition switch to ON (IG).

    3. A01V205E02
      Text in Illustration
      *a

      Component with Harness Connected

      (Power Management Control ECU)

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

      Item Content
      Terminal A26-13 (IWP) - F55-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Ignition switch ON (IG)
      OK
      Waveform duty ratio is between 3% and 9%.

    4. Turn the ignition switch off.


    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

  15. CONNECT SECURELY


    1. Connect the power management control ECU connectors securely.


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  16. CONNECT SECURELY


    1. Connect the inverter water pump assembly connector securely.


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  17. REPAIR OR REPLACE HARNESS OR CONNECTOR


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  18. REPLACE POWER MANAGEMENT CONTROL ECU

    Click here


    NEXT

    CHECK INVERTER WATER PUMP ASSEMBLY Click here

  19. REPLACE HV COOLANT


    1. Replace the HV coolant with coolant having an appropriate concentration (appropriate freeze point) for the vehicle usage conditions Click here.


    NEXT

  20. CHECK INVERTER WATER PUMP ASSEMBLY


    1. Perform a road test and check that DTCs are not stored.

      CAUTION:

      Perform this road test only in an appropriate safe location, in accordance with all local laws.

      OK
      DTCs are not stored.

    OK

    COMPLETED

    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here