HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A78-506, P0A78-808

DTC Code DTC Name
P0A78-506 Drive Motor "A" Inverter Performance
P0A78-808 Drive Motor "A" Inverter Performance

DESCRIPTION

For a description of the inverter.

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If the motor inverter overheats, has a circuit malfunction, or has an internal short, the inverter transmits this information to the MG ECU via the motor inverter fail signal line.

If an abnormal amount of current flows through the motor inverter, the MG ECU detects it and sends a signal to inform the power management control ECU of the malfunction.

Tech Tips

The term "drive motor A" indicates MG2.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P0A78-506 Drive Motor "A" Inverter Performance Motor inverter fail signal detection (overcurrent due to hybrid vehicle transaxle assembly malfunction)

  • Inverter with converter assembly

  • Hybrid vehicle generator assembly

  • Hybrid vehicle motor assembly

  • Wire harness or connector

 Comes on

Master Warning Light:

Comes on
P0A78-808 Drive Motor "A" Inverter Performance Abnormal MG2 current value detection (Hybrid vehicle transaxle assembly malfunction)

  • Inverter with converter assembly

  • Hybrid vehicle generator assembly

  • Hybrid vehicle motor assembly

  • Wire harness or connector

 Comes on

Master Warning Light:

Comes on

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A1A-200.

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CAUTION / NOTICE / HINT

CAUTION:


  • Before inspecting the high-voltage system or disconnecting the low voltage connector of the inverter with converter assembly, take safety precautions such as wearing insulated gloves and removing the service plug grip to prevent electrical shocks. After removing the service plug grip, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • After removing the service plug grip, wait for at least 10 minutes before touching any of the high-voltage connectors or terminals. After waiting for 10 minutes, check the voltage at the terminals in the inspection point in the inverter with converter assembly. The voltage should be 0 V before beginning work.

    Click here

    Tech Tips

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

Note

After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work.

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PROCEDURE


  1. CHECK DTC OUTPUT (HYBRID CONTROL)


    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. Check for DTCs.


      Powertrain > Hybrid Control > Trouble Codes
      Result
      Result Proceed to
      P0A78-202 is not output. A
      P0A78-202 is also output. B

      Note


      • If P0A78-202 is output, troubleshoot it first. After completing the troubleshooting for P0A78-202, perform troubleshooting for this DTC.

      • Parts repaired or replaced during troubleshooting for P0A78-202 do not need to be re-inspected in this diagnosis procedure.

    5. Turn the power switch off.


    B

    GO TO DTC CHART (P0A78-202) Click here

    A

  2. CHECK DTC OUTPUT (HYBRID CONTROL)


    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. Check for DTCs.


      Powertrain > Hybrid Control > Trouble Codes

      Tech Tips


      • If P0A78-202 was not output in step 1 of this diagnosis procedure, check Table 1 below.

      • If P0A78-202 was output in step 1 of this diagnosis procedure, diagnose that DTC first, then check Table 2 below.

      Result
      Result Proceed to
      P0A78-506 or 808 only is output, or DTCs except the ones in the tables below are also output. A
      Any of the following DTCs are also output. B
      Table 1
      DTC No. Relevant Diagnosis
      P0A1A (all INF codes)*1 Generator Control Module
      P0A1B (all INF codes)*1 Drive Motor "A" Control Module
      P0A1D (all INF codes)*1 Hybrid Powertrain Control Module
      P0A3F-243 Drive Motor "A" Position Sensor Circuit
      P0A40-500 Drive Motor "A" Position Sensor Circuit Range / Performance
      P0A41-245 Drive Motor "A" Position Sensor Circuit Low
      P0A4B-253 Generator Position Sensor Circuit
      P0A4C-513 Generator Position Sensor Circuit Range / Performance
      P0A4D-255 Generator Position Sensor Circuit Low
      P0A60 (all INF codes)*1 Drive Motor "A" Phase V Current
      P0A63 (all INF codes)*1 Drive Motor "A" Phase W Current
      P0A72 (all INF codes)*1 Generator Phase V Current
      P0A75 (all INF codes)*1 Generator Phase W Current
      P0A78-266, 267, 586 Drive Motor "A" Inverter Performance
      P0A94-585, 587, 589, 590 DC / DC Converter Performance
      P0C76-523 Hybrid Battery System Discharge Time Too Long
      Table 2
      DTC No. Relevant Diagnosis
      P0A1A (all INF codes)*1 Generator Control Module
      P0A1B (all INF codes)*1 Drive Motor "A" Control Module
      P0A1D (all INF codes)*1 Hybrid Powertrain Control Module
      P0A3F-243 Drive Motor "A" Position Sensor Circuit
      P0A40-500 Drive Motor "A" Position Sensor Circuit Range / Performance
      P0A41-245 Drive Motor "A" Position Sensor Circuit Low
      P0A4B-253 Generator Position Sensor Circuit
      P0A4C-513 Generator Position Sensor Circuit Range / Performance
      P0A4D-255 Generator Position Sensor Circuit Low
      P0A60-294 Drive Motor "A" Phase V Current
      P0A63-302 Drive Motor "A" Phase W Current
      P0A72 (all INF codes)*1 Generator Phase V Current
      P0A75 (all INF codes)*1 Generator Phase W Current
      P0A78-266, 267, 586 Drive Motor "A" Inverter Performance
      P0A94-585, 587, 589, 590 DC / DC Converter Performance
      P0C76-523 Hybrid Battery System Discharge Time Too Long

      Tech Tips


      • *1: If any INF codes are output for this DTC, refer to the corresponding diagnostic procedure.

      • P0A78-506 or P0A78-808 may be stored due to a malfunction which also causes DTCs in the preceding tables to be stored. In this case, first troubleshoot the output DTCs in the preceding tables. Then, perform a test to attempt to reproduce the problems, and check that no DTCs are output.

    5. Turn the power switch off.


    B

    GO TO DTC CHART (HYBRID CONTROL SYSTEM) Click here

    A

  3. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. A01SFRS

      Check the connector connections and contact pressure of the low voltage connectors of the inverter with converter assembly.

      Click here

      Note

      Before disconnecting the connector, confirm that it is properly connected by checking that the locking claws are engaged and that the connector does not pull out.

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

      Tech Tips

      When connecting the connector, insert it with the locking lever in the raised position. Rotate the lever downward and make sure that the connector is pulled into its socket. When the locking lever is in its fully closed position, a click will be heard as its locking claws engage. After the click is heard, pull up on the connector to confirm that it is properly connected.

      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  4. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - GENERATOR RESOLVER)

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the B179 inverter with converter assembly connector.

    3. Connect the cable to the negative (-) auxiliary battery terminal.

    4. Turn the power switch on (IG).

    5. A0031ZXC08
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B179-11 (GRF) - Body ground Power switch on (IG) Below 1 V
      B179-12 (GRFG) - Body ground Power switch on (IG) Below 1 V
      B179-7 (GSN) - Body ground Power switch on (IG) Below 1 V
      B179-8 (GSNG) - Body ground Power switch on (IG) Below 1 V
      B179-10 (GCS) - Body ground Power switch on (IG) Below 1 V
      B179-9 (GCSG) - Body ground Power switch on (IG) Below 1 V

      Note

      Turning the power switch on (IG) with the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    6. Turn the power switch off.

    7. Disconnect the cable from the negative (-) auxiliary battery terminal.

    8. Reconnect the B179 inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK GENERATOR RESOLVER

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the B179 inverter with converter assembly connector.

    3. A0031ZXC08
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B179-11 (GRF) - B179-12 (GRFG) Power switch off 7.1 to 21.6 Ω
      B179-7 (GSN) - B179-8 (GSNG) Power switch off 13.7 to 34.5 Ω
      B179-10 (GCS) - B179-9 (GCSG) Power switch off 12.8 to 32.4 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B179-11 (GRF) or B179-12 (GRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B179-7 (GSN) or B179-8 (GSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B179-10 (GCS) or B179-9 (GCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

    4. Reconnect the B179 inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR) Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - MOTOR RESOLVER)

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the B179 inverter with converter assembly connector.

    3. Connect the cable to the negative (-) auxiliary battery terminal.

    4. Turn the power switch on (IG).

    5. A0031ZXC07
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B179-1 (MRF) - Body ground Power switch on (IG) Below 1 V
      B179-2 (MRFG) - Body ground Power switch on (IG) Below 1 V
      B179-3 (MSN) - Body ground Power switch on (IG) Below 1 V
      B179-4 (MSNG) - Body ground Power switch on (IG) Below 1 V
      B179-6 (MCS) - Body ground Power switch on (IG) Below 1 V
      B179-5 (MCSG) - Body ground Power switch on (IG) Below 1 V

      Note

      Turning the power switch on (IG) with the inverter with converter assembly disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    6. Turn the power switch off.

    7. Disconnect the cable from the negative (-) auxiliary battery terminal.

    8. Reconnect the B179 inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK MOTOR RESOLVER

    Result
    Proceed to
    OK
    NG

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed.

      Note

      After removing the service plug grip, do not turn the power switch on (READY), unless instructed by the repair manual because this may cause a malfunction.

    2. Disconnect the B179 inverter with converter assembly connector.

    3. A0031ZXC07
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B179-1 (MRF) - B179-2 (MRFG) Power switch off 7.1 to 21.6 Ω
      B179-3 (MSN) - B179-4 (MSNG) Power switch off 13.7 to 34.5 Ω
      B179-6 (MCS) - B179-5 (MCSG) Power switch off 12.8 to 32.4 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B179-1 (MRF) or B179-2 (MRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B179-3 (MSN) or B179-4 (MSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B179-6 (MCS) or B179-5 (MCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

    4. Reconnect the B179 inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR) Click here

    OK

  8. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. A003237

      Check the connection of the generator resolver connector.

      OK
      The connector is connected securely and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  9. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. A0031Y3

      Check the connection of the motor resolver connector.

      OK
      The connector is connected securely and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    OK

    REFER TO REPLACE INVERTER WITH CONVERTER ASSEMBLY PARTS Click here

    NG

    CONNECT SECURELY

  10. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. A0031Y3

      Check the connection of the motor resolver connector.

      OK
      The connector is connected securely and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  11. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (MOTOR RESOLVER)

    Result
    Proceed to
    OK
    NG

    1. A0031Y3N01

      Disconnect the B168 motor resolver connector.

    2. A00324EC01
      *a

      Component without harness connected

      (Motor Resolver (Hybrid Vehicle Transaxle Assembly))

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

      Standard Resistance (Check for Open)
      Tester Connection Condition Specified Condition
      B168-3 (MRF) - B168-6 (MRFG) Power switch off 7.1 to 21.6 Ω
      B168-1 (MSN) - B168-4 (MSNG) Power switch off 13.7 to 34.5 Ω
      B168-2 (MCS) - B168-5 (MCSG) Power switch off 12.8 to 32.4 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B168-3 (MRF) - Body ground and other terminals Power switch off 1 MΩ or higher
      B168-6 (MRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B168-1 (MSN) - Body ground and other terminals Power switch off 1 MΩ or higher
      B168-4 (MSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B168-2 (MCS) - Body ground and other terminals Power switch off 1 MΩ or higher
      B168-5 (MCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

      Tech Tips

      The motor resolver is not available as a supply part. If it requires replacement, replace the hybrid vehicle transaxle assembly.

    3. Reconnect the B168 motor resolver connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG

    REPLACE HYBRID VEHICLE MOTOR ASSEMBLY Click here

  12. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)

    Result
    Proceed to
    OK
    NG

    1. A003237

      Check the connection of the generator resolver connector.

      OK
      The connector is connected securely and there are no contact problems.
      Result
      Proceed to
      OK
      NG

    NG

    CONNECT SECURELY

    OK

  13. INSPECT HYBRID VEHICLE TRANSAXLE ASSEMBLY (GENERATOR RESOLVER)

    Result
    Proceed to
    OK
    NG

    1. A003237N01

      Disconnect the B166 generator resolver connector.

    2. A00328TC03
      *a

      Component without harness connected

      (Generator Resolver (Hybrid Vehicle Transaxle Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      B166-1 (GRF) - B166-5 (GRFG) Power switch off 7.1 to 21.6 Ω
      B166-2 (GSN) - B166-6 (GSNG) Power switch off 13.7 to 34.5 Ω
      B166-3 (GCS) - B166-7 (GCSG) Power switch off 12.8 to 32.4 Ω
      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition
      B166-1 (GRF) - Body ground and other terminals Power switch off 1 MΩ or higher
      B166-5 (GRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B166-2 (GSN) - Body ground and other terminals Power switch off 1 MΩ or higher
      B166-6 (GSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      B166-3 (GCS) - Body ground and other terminals Power switch off 1 MΩ or higher
      B166-7 (GCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

      Tech Tips

      The generator resolver is not available as a supply part. If it requires replacement, replace the hybrid vehicle transaxle assembly.

    3. Reconnect the B166 generator resolver connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG

    REPLACE HYBRID VEHICLE GENERATOR ASSEMBLY Click here