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 information to the power management control ECU. The power management control ECU monitors the revolution and detects malfunctions.

DTC No. INF Code DTC Detection Condition Trouble Area
P0C73 776

A speed or intermittent stop malfunction occurs in the inverter water pump assembly.

A revolution malfunction (speed is too high/low) or an intermittent stop malfunction (operation stops intermittently when the revolution speed is abnormal) occurs in the inverter water pump assembly.

  • 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. INF Code Data List Item
P0C73 776

  • W/P Run Control Duty*1

  • Inverter W/P Revolution

  • Ready Signal

*1: This Data List item is related to the inverter water pump assembly.

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

*2: This is an Active Test of the inverter water pump assembly.

WIRING DIAGRAM

A005BW2E10

CAUTION / NOTICE / HINT

Note


  • 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.

  • 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


    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
      HV 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 LEAK

    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 operation command 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.

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

    5. 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.

    6. Turn the power switch off.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR) 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. Clear DTCs and freeze frame data.

    5. Turn the power switch off.


    NEXT

  5. PERFORM ACTIVE TEST USING GTS (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. the GTS 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
      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.


    NG

    CHECK CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT 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 power switch on (IG).

    3. Read the freeze frame data Ambient Temperature using the GTS.

    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 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.

    5. Turn the power switch off.


    A

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    B

    REPLACE HV COOLANT

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


    1. Check the connector connections and contact pressure of the relevant terminals for the power management control ECU connectors Click here.

      A005DLOE01
      Text in Illustration
      *A for LHD *B for RHD
      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. A005BDE

      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 pressure problems.

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the A21 power management control ECU connector.

    2. Disconnect the g1 inverter water pump assembly connector.

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

      A005EIUE02
      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 Assembly)
      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      g1-3 (SWP) - A21-13 (IWP) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      g1-3 (SWP) or A21-13 (IWP) - Body ground and other terminals Power switch off 10 kΩ or higher

    4. Reconnect the A21 power management control ECU connector.

    5. Reconnect the g1 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. A005EU8E02
      Text in Illustration
      *1 Engine Room Relay Block and Junction Block Assembly
      *2 IGCT No. 3 Fuse

      Remove the IGCT No. 3 fuse from the engine room relay block and junction block assembly.

    3. Turn the power switch on (IG).

    4. Enter the following menus: Powertrain / Hybrid Control / ECU Data List / 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 IGCT No. 3 fuse.


    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here

    OK

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


    1. Disconnect the A21 power management control ECU connector.

    2. Turn the power switch on (IG).

    3. A0059WCE02
      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 Condition Specified Condition
      A21-13 (IWP) - L5-6 (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 A21 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. A005AE2E02
      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 Content
      Terminal A21-13 (IWP) - L5-6 (E1)
      Equipment Setting 5 V/DIV., 50 ms./DIV.
      Condition Power switch on (IG)
      OK
      Waveform duty ratio is between 3% and 9%.

    3. Turn the power switch off.


    OK

    REPLACE INVERTER WATER PUMP ASSEMBLY Click here

    NG

    REPLACE POWER MANAGEMENT CONTROL ECU Click here