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 with motor assembly transmits rotation revolution speed information to the power management control ECU. The power management control ECU monitors the revolution speed and detects malfunctions.

DTC No. DTC Detection Condition Trouble Area
P0C73-776

The inverter water pump with motor assembly revolution speed is abnormally high or low (or stop) for 1 minute or more or the inverter water pump with motor assembly stops intermittently after abnormal revolution speed is detected.

(1 trip detection logic)

  • Inverter cooling system

  • Wire harness or connector

  • Inverter water pump with motor assembly

  • Power management control ECU

Tech Tips

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

Related Data List
DTC No. 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

A01FV1AE04

INSPECTION PROCEDURE

Note

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

Tech Tips


  • When an overvoltage condition in the auxiliary battery voltage occurs due to receiving external assistance, etc., control may be stopped temporarily and this DTC may be output due to the self-protection function of the inverter water pump with motor assembly. (When there is no longer an overvoltage condition in the auxiliary battery voltage, control resumes. Therefore, it is not necessary to replace the inverter water pump with motor assembly.)

  • 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 (when the power switch is turned on (READY), the inverter water pump with motor assembly operates).

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

      Note

      The inverter water pump with motor assembly has a protection function that activates when there is an HV coolant leak. Therefore, it is not necessary to replace the inverter water pump with motor assembly unless the cause of the HV coolant leak is the inverter water pump with motor assembly.

      Tech Tips

      After repairing the HV coolant leaks and adding coolant, perform the "(Inverter) " 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 HV COOLANT LEAK AND ADD COOLANT

    A

  2. CHECK COOLANT HOSE


    1. Check that the cooling system hoses are not kinked or clogged.


    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 with motor assembly may not operate.

    • When the inverter water pump with motor assembly signal line (SWP - IWP) is open or its connection is faulty, the inverter water pump with motor 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.

    4. Read the Data List.

      Result
      Tester Display Switch Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 625 rpm or less

      Tech Tips

      When the inverter water pump with motor 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.


    NG

    Click here

    OK

  4. CLEAR DTC


    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.

    5. Clear the DTCs and freeze frame data.

    6. Turn the power switch off.


    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 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 / 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
      Tester Display Switch Condition Specified Condition
      Inverter W/P Revolution Power switch on (IG) 2375 to 5750 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 with motor 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.


    NG

    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 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.

    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 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 stored.

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

      • If a DTC is stored 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 stored.

    6. Turn the power switch off.


    B

    REPLACE HV COOLANT Click here

    A

    REPLACE INVERTER WATER PUMP WITH MOTOR ASSEMBLY Click here

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


    1. A01FQC6E01
      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

    OK

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


    1. A01FUMK

      Check the connector connections and contact pressure of the relevant terminals for the inverter water pump with motor 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 (POWER MANAGEMENT CONTROL ECU - INVERTER WATER PUMP WITH MOTOR ASSEMBLY)


    1. Disconnect the A35 power management control ECU connector.

    2. Disconnect the A26 inverter water pump with motor assembly connector.

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

      A01FS70E05
      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 with Motor Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      A35-13 (IWP) - A26-3 (SWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      A35-13 (IWP) or A26-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A26 inverter water pump with motor assembly connector.

    5. Reconnect the A35 power management control ECU 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 with motor assembly may not operate.


    1. Connect the GTS to the DLC3.

    2. A01FVKME01
      Text in Illustration
      *1 No. 1 Engine Room Relay Block and Junction Block Assembly
      *2 INV W/P Fuse

      Remove the INV W/P fuse from the No. 1 engine room relay block and junction block assembly.

    3. Turn the power switch on (IG).

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

    5. Read the Data List.

      Result
      Tester Display Switch 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/P fuse.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

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


    1. Disconnect the A35 power management control ECU connector.

    2. Turn the power switch on (IG).

    3. A01FQSYE32
      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 Display Switch Condition Specified Condition
      A35-13 (IWP) - N91-6 (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 A35 power management control ECU connector.


    NG

    REPLACE INVERTER WATER PUMP WITH MOTOR ASSEMBLY Click here

    OK

  12. CHECK POWER MANAGEMENT CONTROL ECU (CHECK WAVEFORM)


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

    2. Turn the power switch on (IG).

    3. A01FV0LE20
      Text in Illustration
      *a

      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 Condition
      Terminal A35-13 (IWP) - N91-6 (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.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

    REPLACE INVERTER WATER PUMP WITH MOTOR ASSEMBLY Click here