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 speed information to the power management control ECU (HV CPU). The power management control ECU (HV CPU) monitors the revolution 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

Tech Tips

The inverter water pump assembly operates when the power switch is on (READY).

Related Data List
DTC No. Data List Item
P0C73-776

  • W/P Run Control Duty*1

  • Inverter W/P Revolution

  • Ready Signal

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

WIRING DIAGRAM

A01NI3VE22

INSPECTION PROCEDURE

Note


  • If DTC P0A78-284, 286, P0A79-692, 696, P0A7A-322, 324, P0A94-553 or 557 is output, replace the inverter with converter assembly after this inspection.

  • 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.

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 LEAKS

    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 signal 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.

      OK
      Inverter W/P Revolution is 625 rpm or less.

      Tech Tips

      When the inverter water pump assembly is not operating, the Data List item "Inverter W/P Revolution" usually displays 625 rpm continuously.

    6. Turn the power switch off.


    NG

    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 / Trouble Codes.

    4. Clear DTCs and freeze frame data.


    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
      Data List Item Specified Condition
      Inverter W/P Revolution 2375 to 5375 rpm

      Tech Tips


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

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

    6. Turn the power switch off.


    NG

    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 assemblyp, 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.


    B

    Click here

    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

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


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

      A01NJQWE01
      Text in Illustration
      *1 for LHD *2 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. A01NLPZ

      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 A80 from the power management control ECU.

    2. Disconnect connector A73 from the inverter water pump assembly.

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

      A01NIO2E03
      Text in Illustration
      *1

      Rear view of wire harness connector

      (to Power Management Control ECU)

      		 *2

      Front view of wire harness connector

      (to Inverter Water Pump Assembly)
      Standard Resistance (Check for open)
      Tester Connection Switch Condition Specified Condition
      A73-3 (SWP) - A80-13 (IWP) Power switch off Below 1 Ω
      Standard Resistance (Check for short)
      Tester Connection Switch Condition Specified Condition
      A73-3 (SWP) or A80-13 (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. CHECK POWER MANAGEMENT CONTROL ECU

    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. Remove the INV W/P fuse from the engine room relay block No. 2.

    3. Turn the power switch on (IG).

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

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

    6. Read the Data List.

      OK
      Inverter W/P Revolution is 125 rpm or less.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    7. Turn the power switch off.

    8. Install the INV W/P fuse.


    B

    REPLACE POWER MANAGEMENT CONTROL ECU (for LHD) Click here

    C

    REPLACE POWER MANAGEMENT CONTROL ECU (for RHD) Click here

    A

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


    1. Disconnect the A80 power management control ECU connector.

    2. Turn the power switch on (IG).

    3. A01NLLEE54
      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
      A80-13 (IWP) - F97-6 (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. Reconnect the A80 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. A01NMFME25
      Text in Illustration
      *1

      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 A80-13 (IWP) - F97-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Power switch on (IG)
      OK
      Waveform duty ratio is between 3% and 9%.
      Result
      Result Proceed to
      OK A
      NG (for LHD) B
      NG (for RHD) C

    3. Turn the power switch off.


    B

    REPLACE POWER MANAGEMENT CONTROL ECU (for LHD) Click here

    C

    REPLACE POWER MANAGEMENT CONTROL ECU (for RHD) Click here

    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

  13. 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

    COMPLETED