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 hybrid vehicle control ECU. The hybrid vehicle control ECU monitors the speed and detects malfunctions.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P0C73-776 Motor Electronics Coolant Pump "A" Control Performance

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

  • Hybrid vehicle control ECU

 Comes on

Master Warning Light:

Comes on

Tech Tips

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

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

  • Inverter W/P Revolution

  • (Inverter) W/P Run Control Duty

  • Ready Signal
Related Active Test
DTC No. Active Test
P0C73-776 Activate the (Inverter) Water Pump

WIRING DIAGRAM

A00024ZE12

CAUTION / NOTICE / HINT

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.

  • 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.)

  • If air enters the system while bleeding air during coolant exchange, etc. 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 hybrid vehicle 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

    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

    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 "Activate the (Inverter) 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.

      • The inverter water pump assembly will not malfunction due to coolant leaks.


    B

    ADD HV COOLANT

    C

    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.

    A

  2. CHECK COOLANT HOSE

    Result
    Proceed to
    OK
    NG

    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

  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.

    • 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 GTS to the DLC3.

    2. Turn the power switch on (IG).

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


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter W/P Revolution

    4. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 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.

    5. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK CONNECTOR CONNECTION CONDITION (HYBRID VEHICLE CONTROL ECU CONNECTOR) Click here

    OK

  4. CLEAR DTC

    Result
    Proceed to
    NEXT

    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

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

    4. Read and record the DTCs and freeze frame data.


      Powertrain > Hybrid Control > Trouble Codes

    5. Clear the DTCs and freeze frame data.


      Powertrain > Hybrid Control > Clear DTCs

    6. Turn the power switch off.

      Result
      Proceed to
      NEXT

    NEXT

  5. READ VALUE USING GTS (ACTIVATE THE (INVERTER) 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 power switch on (IG).

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


      Powertrain > Hybrid Control > Active Test
      Tester Display
      Activate the (Inverter) Water Pump

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


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter W/P Revolution

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

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power 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).

      • 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.

      Result
      Proceed to
      OK
      NG

    NG

    GO TO STEP 7 Click here

    OK

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

    1. Connect the GTS to the DLC3

    2. Turn the power switch on (IG).

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

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


      Powertrain > Hybrid Control > Trouble Codes

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

    6. Turn the power switch off.


    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    B

    REPLACE HV COOLANT Click here

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

    Result
    Proceed to
    OK
    NG

    1. A01CQIMC01
      *A for LHD
      *B for RHD

      Check the connector connections and contact pressure of the relevant terminals for the hybrid vehicle control ECU 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

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


    1. A0000VE

      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 and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the A60 hybrid vehicle control ECU connector.

    2. Disconnect the A55 inverter water pump assembly connector.

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

      A0001TBC16
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 *b

      Front view of wire harness connector

      (to Inverter Water Pump Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      A60-13 (IWP) - A55-3 (SWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      A60-13 (IWP) or A55-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A55 inverter water pump assembly connector.

    5. Reconnect the A60 hybrid vehicle control ECU connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. 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. A000134C02
      *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 / Hybrid Control / Data List / Inverter W/P Revolution.


      Powertrain > Hybrid Control > Data List
      Tester Display
      Inverter W/P Revolution

    5. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 125 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 Click here

    OK

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


    1. Disconnect the A60 hybrid vehicle control ECU connector.

    2. Turn the power switch on (IG).

    3. B002KSTC68
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A60-13 (IWP) - I115-6 (E1) Power switch on (IG) 11 to 14 V

      Note

      Turning the power switch on (IG) with the hybrid vehicle 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 A60 hybrid vehicle control ECU connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  12. 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. A00017PC32
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU)

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

      Item Content
      Terminal A60-13 (IWP) - I115-6 (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

    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU Click here