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 hybrid vehicle control ECU. The hybrid vehicle control ECU 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 is detected.

(1 trip detection logic)

  • Inverter cooling system

  • Wire harness or connector

  • Inverter water pump assembly

  • Hybrid vehicle control ECU
Related Data List
DTC No. Data List
P0C73-776

  • Inverter W/P Revolution

  • (Inverter) W/P Run Control Duty

The following items can be helpful when performing repairs:


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

WIRING DIAGRAM

A01UZ71E11

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
      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
      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.

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


    B

    ADD HV COOLANT

    C

    INSPECT FOR HV COOLANT LEAK AND ADD COOLANT

    A

  2. CHECK COOLANT HOSE


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


    NG

    CORRECT THE PROBLEM

    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 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

      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 ignition switch off.


    NG

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

    OK

  4. CLEAR DTC


    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. Clear DTCs and freeze frame data.

    5. Turn the ignition switch off.


    NEXT

  5. PERFORM ACTIVE TEST 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 ignition switch to ON (IG).

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

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

    5. While performing the "Activate the (Inverter) 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) 3000 to 9300 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 ignition switch off.


    NG

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

    OK

  6. 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 below freezing temperature of the HV coolant. A
      Ambient Temperature value is above 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 HV COOLANT

    B

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

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


    1. A01V0I0E02
      Text in Illustration
      *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.

    NG

    CONNECT SECURELY

    OK

  8. 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 Click here.

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

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the hybrid vehicle control ECU connector.

    2. Disconnect the inverter water pump assembly connector.

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

      A01UYPQE02
      Text in Illustration
      *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 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 hybrid vehicle control ECU connector.

    5. Connect the inverter water pump assembly connector.


    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. A01V1FKE02
      Text in Illustration
      *1 No. 2 Engine Room Relay Block
      *2 IGCT NO. 3 Fuse

      Remove the IGCT NO. 3 fuse from the No. 2 engine room relay block.

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

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

    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. Install the IGCT NO. 3 fuse.


    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 hybrid vehicle control ECU connector.

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

    3. A01UZHME02
      Text in Illustration
      *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 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 hybrid vehicle 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 hybrid vehicle control ECU connector.


    NG

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    OK

  12. CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM)


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

    2. A01UYYSE02
      Text in Illustration
      *a

      Component with Harness Connected

      (Hybrid Vehicle Control ECU)

      While turning the ignition switch to ON (IG), check the waveform between the hybrid vehicle 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%.

    3. Turn the ignition switch off.


    NG

    REPLACE HYBRID VEHICLE CONTROL ECU Click here

    OK

  13. REPLACE INVERTER WATER PUMP ASSEMBLY


    1. Replace the inverter water pump assembly Click here.


    NEXT

  14. ADD HV COOLANT AND PERFORM AIR BLEEDING


    1. After replacing the inverter water pump assembly, add HV coolant and perform air bleeding Click here.


    NEXT

    COMPLETED