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, Click here.

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 (HV CPU) of the malfunction.

DTC No. INF Code DTC Detection Condition Trouble Area
P0A78 506 Motor inverter fail signal detection (overcurrent due to hybrid vehicle transaxle assembly malfunction)

  • Inverter with converter assembly

  • Hybrid vehicle transaxle assembly

  • Hybrid vehicle generator assembly

  • Wire harness or connector
P0A78 808 Abnormal MG2 current value detection (Hybrid vehicle transaxle assembly malfunction)

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A1A-200 Click here.

INSPECTION PROCEDURE

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 disconnecting 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.

Tech Tips

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

PROCEDURE


  1. CHECK DTC OUTPUT (HV)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Check if DTCs are output.

      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, return to 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 Click here

    A

  2. CHECK DTC OUTPUT (HV)


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes.

    4. Check if DTCs are output.

      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, repair that DTC first, then check Table 2 below.

      Result
      Result Proceed to
      P0A78-506 or 808 only is 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
      P0A1C (all INF codes)*1 Drive Motor "B" 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
      P0A45-669 Drive Motor "B" Position Sensor Circuit
      P0A46-671 Drive Motor "B" Position Sensor Circuit Range/Performance
      P0A47-670 Drive Motor "B" 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
      P0A69 (all INF codes)*1 Drive Motor "B" Phase V Current
      P0A6C (all INF codes)*1 Drive Motor "B" 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
      P0A1C (all INF codes)*1 Drive Motor "B" 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
      P0A45-669 Drive Motor "B" Position Sensor Circuit
      P0A46-671 Drive Motor "B" Position Sensor Circuit Range/Performance
      P0A47-670 Drive Motor "B" 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
      P0A69 (all INF codes)*1 Drive Motor "B" Phase V Current
      P0A6C (all INF codes)*1 Drive Motor "B" 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 set due to a malfunction which also causes DTCs in the preceding table to be set. In this case, first troubleshoot the output DTCs in the preceding table. 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 Click here

    A

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

    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.

      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.

      A01NHWR

    2. Check the connection of the low voltage connector of the inverter with converter assembly.

      OK
      The connector is connected securely and there are no contact 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.


    NG

    CONNECT SECURELY

    OK

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

    CAUTION:

    Be sure to wear insulated gloves.


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. Turn the power switch on (IG).

    3. A01NDPLE01
      Text in Illustration
      *1

      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 Switch Condition Specified Condition
      D44-1 (GRF) - Body ground Power switch on (IG) Below 1 V
      D44-7 (GRFG) - Body ground Power switch on (IG) Below 1 V
      D44-2 (GSN) - Body ground Power switch on (IG) Below 1 V
      D44-8 (GSNG) - Body ground Power switch on (IG) Below 1 V
      D44-3 (GCS) - Body ground Power switch on (IG) Below 1 V
      D44-9 (GCSG) - Body ground Power switch on (IG) Below 1 V

      Note

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

    4. Turn the power switch off.

    5. Connect the low voltage connector from the inverter with converter assembly.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK GENERATOR RESOLVER


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. A01NDPLE01
      Text in Illustration
      *1

      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 Switch Condition Specified Condition
      D44-1 (GRF) - D44-7 (GRFG) Power switch off 4.2 to 12.5 Ω
      D44-2 (GSN) - D44-8 (GSNG) Power switch off 9.8 to 20.1Ω
      D44-3 (GCS) - D44-9 (GCSG) Power switch off 9.8 to 20.1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      D44-1 (GRF) or D44-7 (GRFG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D44-2 (GSN) or D44-8 (GSNG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D44-3 (GCS) or D44-9 (GCSG) - Body ground and other terminals Power switch off 10 kΩ or higher

    3. Connect the inverter with converter assembly connector.


    NG

    Click here

    OK

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

    CAUTION:

    Be sure to wear insulated gloves.


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. Turn the power switch on (IG).

    3. A01NDPLE02
      Text in Illustration
      *1

      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 Switch Condition Specified Condition
      D44-4 (MRF) - Body ground Power switch on (IG) Below 1 V
      D44-11 (MRFG) - Body ground Power switch on (IG) Below 1 V
      D44-5 (MSN) - Body ground Power switch on (IG) Below 1 V
      D44-12 (MSNG) - Body ground Power switch on (IG) Below 1 V
      D44-6 (MCS) - Body ground Power switch on (IG) Below 1 V
      D44-13 (MCSG) - Body ground Power switch on (IG) Below 1 V

      Note

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

    4. Turn the power switch off.

    5. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK MOTOR RESOLVER


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. A01NDPLE02
      Text in Illustration
      *1

      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 Switch Condition Specified Condition
      D44-4 (MRF) - D44-11 (MRFG) Power switch off 4.2 to 12.5 Ω
      D44-5 (MSN) - D44-12 (MSNG) Power switch off 9.8 to 20.1 Ω
      D44-6 (MCS) - D44-13 (MCSG) Power switch off 9.8 to 20.1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      D44-4 (MRF) or D44-11 (MRFG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D44-5 (MSN) or D44-12 (MSNG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D44-6 (MCS) or D44-13 (MCSG) - Body ground and other terminals Power switch off 10 kΩ or higher

    3. Connect the inverter with converter assembly connector.


    NG

    Click here

    OK

  8. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)


    1. A01NHDI

      Check the connection of the generator resolver connector.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

  9. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)


    1. A01NDIO

      Check the connection of the motor resolver connector.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

  10. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)


    1. A01NHDI

      Check the connection of the generator resolver connector.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. A01ND3RE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Generator Resolver)
      *2

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

      Disconnect the generator resolver connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      D45-1 (GRF) - D44-1 (GRF) Power switch off Below 1 Ω
      D45-6 (GRFG) - D44-7 (GRFG) Power switch off Below 1 Ω
      D45-2 (GSN) - D44-2 (GSN) Power switch off Below 1 Ω
      D45-7 (GSNG) - D44-8 (GSNG) Power switch off Below 1 Ω
      D45-3 (GCS) - D44-3 (GCS) Power switch off Below 1 Ω
      D45-8 (GCSG) - D44-9 (GCSG) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      D45-1 (GRF) or D44-1 (GRF) - Body ground and other terminals Power switch off 10 kΩ or higher
      D45-6 (GRFG) or D44-7 (GRFG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D45-2 (GSN) or D44-2 (GSN) - Body ground and other terminals Power switch off 10 kΩ or higher
      D45-7 (GSNG) or D44-8 (GSNG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D45-3 (GCS) or D44-3 (GCS) - Body ground and other terminals Power switch off 10 kΩ or higher
      D45-8 (GCSG) or D44-9 (GCSG) - Body ground and other terminals Power switch off 10 kΩ or higher

      Tech Tips

      The generator resolver is not available separately. If it requires replacement, replace the hybrid vehicle transaxle assembly.

    4. Connect the generator resolver connector.

    5. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE GENERATOR ASSEMBLY Click here

  12. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)


    1. A01NDIO

      Check the connection of the motor resolver connector.

      OK
      The connector is connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

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


    1. Disconnect the low voltage connector D44 from the inverter with converter assembly.

    2. A01NG1VE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Motor Resolver)
      *2

      Front view of wire harness connector

      (to Inverter with Converter Assembly)

      Disconnect the motor resolver connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      D46-1 (MRF) - D44-4 (MRF) Power switch off Below 1 Ω
      D46-4 (MRFG) - D44-11 (MRFG) Power switch off Below 1 Ω
      D46-2 (MSN) - D44-5 (MSN) Power switch off Below 1 Ω
      D46-5 (MSNG) - D44-12 (MSNG) Power switch off Below 1 Ω
      D46-3 (MCS) - D44-6 (MCS) Power switch off Below 1 Ω
      D46-6 (MCSG) - D44-13 (MCSG) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      D46-1 (MRF) or D44-4 (MRF) - Body ground and other terminals Power switch off 10 kΩ or higher
      D46-4 (MRFG) or D44-11 (MRFG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D46-2 (MSN) or D44-5 (MSN) - Body ground and other terminals Power switch off 10 kΩ or higher
      D46-5 (MSNG) or D44-12 (MSNG) - Body ground and other terminals Power switch off 10 kΩ or higher
      D46-3 (MCS) or D44-6 (MCS) - Body ground and other terminals Power switch off 10 kΩ or higher
      D46-6 (MCSG) or D44-13 (MCSG) - Body ground and other terminals Power switch off 10 kΩ or higher

      Tech Tips

      The motor resolver is not available separately. If it requires replacement, replace the hybrid vehicle transaxle assembly.

    4. Connect the motor resolver connector.

    5. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Click here