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 EV control ECU. The EV control ECU monitors the speed and detects malfunctions.

DTC No. Detection Item DTC Detection Condition Trouble Area 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

  • EV water pump with motor assembly

  • EV control ECU

Master Warning Light:

Comes on

Tech Tips

The EV water pump with motor assembly operates when the power switch is on (READY).

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

  • Inverter Water Pump Revolution

  • Inverter Water Pump Run Control Duty

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

WIRING DIAGRAM

A01MJ4OE01

CAUTION / NOTICE / HINT

Note


  • If DTC P0A78-284, 286, P1D82-464, 468, 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 EV water pump with motor assembly may suspend control as a self-protection function and store DTC.

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

  • If air enters the system while bleeding air during coolant exchange, etc. and the EV water pump with motor assembly revolution speed becomes abnormally high, the EV water pump with motor assembly may suspend control as a fail-safe function and the EV control ECU may store this DTC.

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

  • When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work(If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).

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 EV COOLANT

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

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

    2. Check for EV coolant leaks.

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

      Tech Tips


      • After repairing the EV coolant leaks and adding coolant, perform the "Activate the Water Pump" Active Test (EV Active Test item) and the "Control the Electric Cooling Fan" Active Test (FC Active Test item) and make sure that there are no malfunctions.

      • The EV water pump with motor assembly will not malfunction due to coolant leaks.


    B

    ADD EV COOLANT

    C

    INSPECT FOR EV COOLANT LEAK

    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 WATER PUMP 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 / EV / Data List / Inverter Water Pump Revolution.


      Powertrain > EV > Data List
      Tester Display
      Inverter Water Pump Revolution

    4. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter Water Pump 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 Water Pump Revolution" displays a value lower than 625 rpm.

    5. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK CONNECTOR CONNECTION CONDITION (EV 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 / EV / Trouble Codes.

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


      Powertrain > EV > Trouble Codes

    5. Clear the DTCs and freeze frame data.


      Powertrain > EV > Clear DTCs

    6. Turn the power switch off and wait 3 minutes or more.

      Result
      Proceed to
      NEXT

    NEXT

  5. READ VALUE USING GTS (ACTIVATE THE WATER PUMP)

    Note

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

    Tech Tips

    When the auxiliary battery voltage is low, the EV water pump with motor assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

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

    4. Select "Inverter Water Pump Revolution" in the Data List.


      Powertrain > EV > Active Test
      Active Test Display
      Activate the Water Pump
      Data List Display
      Inverter Water Pump Revolution

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

      Result
      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG) 2500 to 5875 rpm

      Tech Tips


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

      • When the EV water pump with motor assembly is not operating, the Data List item "Inverter Water Pump 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 EV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING)

    Result
    Result Proceed to
    Ambient Temperature value is above freezing temperature of the EV coolant. A
    Ambient Temperature value is below freezing temperature of the EV coolant. B

    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / EV / Trouble Codes.

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


      Powertrain > EV > Trouble Codes

    5. Check if the freeze frame data item Ambient Temperature is below the freezing temperature of the EV coolant.

      Result
      Result Proceed to
      Ambient Temperature value is above freezing temperature of the EV coolant. A
      Ambient Temperature value is below freezing temperature of the EV coolant. B

      Tech Tips


      • EV coolant (SLLC) with a 30% concentration freezes at -15°C (5°F) and EV coolant (SLLC) with a 50% concentration freezes at -35°C (-31°F).

      • If the EV coolant freezes in the EV radiator or EV water pump, the coolant temperature in the inverter with converter assembly rises because the EV coolant cannot circulate. As a result, a DTC may be stored.

      • A DTC is stored when the EV water pump impeller cannot rotate due to freezing of the EV 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.


    A

    REPLACE EV WATER PUMP WITH MOTOR ASSEMBLY Click here

    B

    REPLACE EV COOLANT Click here

  7. CHECK CONNECTOR CONNECTION CONDITION (EV CONTROL ECU CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. A01MGTOC01
      *A for LHD
      *B for RHD

      Check the connector connections and contact pressure of the relevant terminals for the EV 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 (EV WATER PUMP WITH MOTOR ASSEMBLY CONNECTOR)


    1. A01MGKS

      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 (EV CONTROL ECU - EV WATER PUMP WITH MOTOR ASSEMBLY)


    1. Disconnect the EV control ECU connector.

    2. Disconnect the EV water pump with motor assembly connector.

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

      A01MG8IC23
      *a

      Rear view of wire harness connector

      (to EV Control ECU)

      		 *b

      Front view of wire harness connector

      (to EV Water Pump with Motor Assembly)
      Standard Resistance
      Tester Connection Condition Specified Condition
      A28-13 (IWP) - D10-3 (SWP) Power switch off Below 1 Ω
      A28-13 (IWP) or D10-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the EV water pump with motor assembly connector.

    5. Reconnect the EV control ECU connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. READ VALUE USING GTS (INVERTER WATER PUMP REVOLUTION)

    Note

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

    Tech Tips

    When the auxiliary battery voltage is low, the EV water pump with motor assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. A01MH9PC10
      *1 Motor Compartment Relay Block
      *2 EV WATER PMP Fuse

      Remove the EV WATER PMP fuse from motor compartment relay block.

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / EV / Data List / Inverter Water Pump Revolution


      Powertrain > EV > Data List
      Tester Display
      Inverter Water Pump Revolution

    5. Read the Data List.

      Result
      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG) 125 rpm or less

    6. Turn the power switch off.

    7. Install the EV WATER PMP fuse.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EV CONTROL ECU Click here

    OK

  11. CHECK HARNESS AND CONNECTOR (EV CONTROL ECU - EV WATER PUMP WITH MOTOR ASSEMBLY)


    1. Disconnect the EV control ECU connector.

    2. Turn the power switch on (IG).

    3. A01MIIJC01
      *a

      Rear view of wire harness connector

      (to EV Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A28-13 (IWP) - G45-6 (E1) Power switch on (IG) 11 to 14 V

      Note

      Turning the power switch on (IG) with the EV 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 EV control ECU connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE EV WATER PUMP WITH MOTOR ASSEMBLY Click here

    OK

  12. CHECK EV CONTROL ECU (CHECK WAVEFORM)


    1. Connect an oscilloscope between the EV control ECU terminals specified in the table below.

    2. Turn the power switch on (IG).

    3. A01MG4FC98
      *a

      Component with harness connected

      (EV Control ECU)

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

      Item Content
      Terminal A28-13 (IWP) - G45-6 (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 EV WATER PUMP WITH MOTOR ASSEMBLY Click here

    NG

    REPLACE EV CONTROL ECU Click here