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Home >> Toyota >> 2020 >> Avalon Limited >> Repair and Diagnosis >> External Pages >> Different car >> Section 42 (Hybrid Control System - Diagnostic Codes (P0AA6-P1C81) (Lithium-Ion)) >> HYBRID CONTROL SYSTEM (for LITHIUM-ION BATTERY) >> DTC P0C73-96: Motor Electronics Coolant Pump "A" Component Internal Failure [08/2020 - ] >> Procedure

DTC P0C73-96: Motor Electronics Coolant Pump "A" Component Internal Failure [08/2020 - ]: Procedure

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  1. CHECK DTC OUTPUT (HYBRID CONTROL) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Enter the following menus: Powertrain/Hybrid Control/Trouble Codes.
    4. Check for DTCs.

      Powertrain > Hybrid Control > Trouble Codes 

      Result

      Result Proceed to
      P0C73-96 only is output, or DTCs except the ones in the table below are also output. A
      Any of the following DTCs including pending DTCs are also output. B
      Malfunction Content Relevant DTC
      Microcomputer malfunction P0606-47 Hybrid/EV Powertrain Control Module Processor Watchdog/Safety MCU Failure
      P0688-1F ECM/PCM Power Relay Sense Circuit Intermittent
      Sensor and actuator circuit malfunction P314A-31 Motor Electronics Coolant Pump "A" No Signal

      HINT: 

      P0C73-96 may be output as a result of the malfunction indicated by the DTCs above.

      1. The chart above is listed in inspection order of priority.
      2. Check DTCs that are output at the same time by following the listed order. (The main cause of the malfunction can be determined without performing unnecessary inspections.)
    5. Turn the power switch off.

    Result: 

    B 

    GO TO DTC CHART (HYBRID CONTROL SYSTEM). Refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2020 - 08/2021]  , or refer to  DIAGNOSTIC TROUBLE CODE CHART [08/2021 - ] 

    Result: 

    A 

    See step  2

  2. READ VALUE USING TECHSTREAM (INVERTER WATER PUMP REVOLUTION) 
    NOTE:

    Be sure to perform the inspection with the auxiliary battery voltage at 12 V or more.

    HINT: 

    • 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 Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Enter the following menus: Powertrain/Hybrid Control/Data List/Inverter Water Pump Revolution.

      Powertrain > Hybrid Control > Data List 

      Tester Display
      Inverter Water Pump Revolution
    4. According to the display on the Techstream, read the Data List.

      OK

      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG) 200 rpm or less

      HINT: 

      When the inverter water pump assembly is not operating, the Data List item "Inverter Water Pump Revolution" displays a value 200 rpm or less.

    5. Turn the power switch off.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  3

  3. CLEAR DTC 

    Refer to PROCEDURE - Step 3

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  4

  4. PERFORM ACTIVE TEST USING TECHSTREAM (ACTIVATE THE INVERTER WATER PUMP) 
    NOTE:
    • Make sure that the HV coolant level is above the low line of the inverter reserve tank.
    • Be sure to perform the inspection with the auxiliary battery voltage at 12 V or more.

    HINT: 

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

    1. Connect the Techstream 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 the Data List item "Inverter Water Pump Revolution".

      Powertrain > Hybrid Control > Active Test 

      Active Test Display
      Activate the Inverter Water Pump
      Data List Display
      Inverter Water Pump Revolution
    5. According to the display on the Techstream, perform the Active Test "Activate the Inverter Water Pump" and, check the value of the Data List item "Inverter Water Pump Revolution".

      OK

      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG)
      During Active Test
      3176 to 8617 rpm

      HINT: 

      • 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 Water Pump Revolution" displays a value 200 rpm or less.
    6. Turn the power switch off.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  6

    Result: 

    OK 

    See step  5

  5. CHECK HV COOLANT (CHECK FOR CONDITIONS THAT MAY HAVE CAUSED FREEZING) 

    Refer to PROCEDURE - Step 8 [08/2020 - 08/2021] , or refer to PROCEDURE - Step 8 [08/2021 - ]

    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

    Result: 

    A 

    See step  12

    Result: 

    B 

    REPLACE HV COOLANT. Refer to  REPLACEMENT [04/2018 - ] 

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

    Refer to PROCEDURE - Step 1

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    CONNECT SECURELY 

    Result: 

    OK 

    See step  7

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

    Refer to PROCEDURE - Step 10 [08/2020 - 08/2021] , or refer to PROCEDURE - Step 10 [08/2021 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    CONNECT SECURELY 

    Result: 

    OK 

    See step  8

  8. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WATER PUMP ASSEMBLY) 
    1. Disconnect the A23 hybrid vehicle control ECU connector.
    2. Disconnect the X1 inverter water pump assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)

      Tester Connection Condition Specified Condition
      A23-13 (IWP) - X1-3 (SWP) Power switch off Below 1 Ω

      Standard Resistance (Check for Short)

      Tester Connection Condition Specified Condition
      A23-13 (IWP) or X1-3 (SWP) - Body ground and other terminals Power switch off 10 kΩ or higher
      GTY898225Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Rear view of wire harness connector
      (to Hybrid Vehicle Control ECU)
      *b Front view of wire harness connector
      (to Inverter Water Pump Assembly)

      HINT: 

      Check the condition (looseness, deterioration, etc.) of the wire to body ground for the inverter water pump assembly.

    4. Reconnect the X1 inverter water pump assembly connector.
    5. Reconnect the A23 hybrid vehicle control ECU connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  9

  9. READ VALUE USING TECHSTREAM (INVERTER WATER PUMP REVOLUTION) 
    NOTE:

    Be sure to perform the inspection with the auxiliary battery voltage at 12 V or more.

    HINT: 

    When the auxiliary battery voltage is low, the inverter water pump assembly may not operate.

    1. Connect the Techstream to the DLC3.
    2. Remove the INV W/PMP fuse from No. 4 relay block.
      GTY744268Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 No. 4 Relay Block
      *2 INV W/PMP Fuse
    3. Turn the power switch on (IG).
    4. Enter the following menus: Powertrain/Hybrid Control/Data List/Inverter Water Pump Revolution.

      Powertrain > Hybrid Control > Data List 

      Tester Display
      Inverter Water Pump Revolution
    5. According to the display on the Techstream, read the Data List.

      OK

      Tester Display Condition Specified Condition
      Inverter Water Pump Revolution Power switch on (IG) 200 rpm or less
    6. Turn the power switch off.
    7. Install the INV W/PMP fuse.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 - ] 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - INVERTER WATER PUMP ASSEMBLY) 
    1. Disconnect the A23 hybrid vehicle control ECU connector.
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.
      GTY850463Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Hybrid Vehicle Control ECU)
      *b Rear view of wire harness connector
      (to Hybrid Vehicle Control ECU)

      Standard Voltage

      Tester Connection Condition Specified Condition
      A23-13 (IWP) - G46-6 (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 A23 hybrid vehicle control ECU connector.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  12

    Result: 

    OK 

    See step  11

  11. CHECK HYBRID VEHICLE CONTROL ECU (CHECK WAVEFORM) 
    1. Connect an oscilloscope between the hybrid vehicle control ECU terminals specified in the table below.
    2. Check the waveform while turning the power switch on (IG).
      GTY856497Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Hybrid Vehicle Control ECU)
      Item Content
      Terminal A23-13 (IWP) - G46-6 (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.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE HYBRID VEHICLE CONTROL ECU. Refer to  REMOVAL [04/2018 - 08/2021]  , or refer to  REMOVAL [08/2021 - ] 

    Result: 

    OK 

    See step  12

  12. REPLACE INVERTER WATER PUMP ASSEMBLY 

    Refer to REMOVAL [04/2018 - ]

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  13

  13. ADD HV COOLANT AND PERFORM AIR BLEEDING 
    1. After replacing the inverter water pump assembly, add HV coolant and perform air bleeding.

      Refer to REPLACEMENT [04/2018 - ]

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END