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 of the malfunction.

Tech Tips

The term "drive motor A" indicates MG2.

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

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

MONITOR DESCRIPTION

P0A78 (INF 506):

If excessive amperage flows through the motor inverter due to an internal short, the motor inverter will transmit an inverter fail signal to the MG ECU. Upon receiving this signal, the power management control ECU will illuminate the MIL and set a DTC.

P0A78 (INF808):

The MG ECU monitors the motor inverter electric current. If the current exceeds the threshold level for a specified period of time, the power management control ECU will illuminate the MIL and set a DTC.

MONITOR STRATEGY

Related DTCs

P0A78 (INF 506): MFIV detection (Over current malfunction)

P0A78 (INF 808): Motor inverter abnormal current
Required sensors / components Motor inverter
Frequency of operation Continuous
Duration TMC's intellectual property
MIL operation 1 driving cycle
Sequence of operation None

TYPICAL ENABLING CONDITIONS

The monitor will run whenever the following DTCs are not present TMC's intellectual property
Other conditions belong to TMC's intellectual property -

TYPICAL MALFUNCTION THRESHOLDS

TMC's intellectual property -

COMPONENT OPERATING RANGE

Power management control ECU DTC P0A78 (INF 506/808) is not detected

CONFIRMATION DRIVING PATTERN

A01HU7ZE02

  1. Connect the Techstream to the DLC3.

  2. Turn the power switch on (IG) and turn the Techstream on.

  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the power switch off.

  5. Turn the power switch on (IG) and check that there are no abnormalities (abnormal sounds, coolant leaks, DTC output, etc).

  6. Turn the power switch on (READY) and turn the Techstream on. [A]

  7. With the shift lever in P, wait for several seconds.

  8. Enter the following menus: Powertrain / Hybrid Control / Trouble Codes. [B]

  9. Check that permanent DTCs are cleared.

  10. If the permanent DTCs are not cleared, perform a universal trip, and then check for permanent DTCs again.

Tech Tips


  • If a permanent DTC is output, the system is malfunctioning.

  • If no permanent DTC is output, the system is normal.

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 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 Click here.

PROCEDURE


  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 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 (P0A78-202) Click here

    A

  2. 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 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
      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 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 (HYBRID CONTROL SYSTEM) 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.

    2. 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.

      A01HVLPE01
      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.


    NG

    CONNECT SECURELY

    OK

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

    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 connector E1 from the inverter with converter assembly.

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

    4. Turn the power switch on (IG).

    5. A01HUMVE01
      Text in Illustration
      *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 Switch Condition Specified Condition
      E1-1 (GRF) - Body ground Power switch on (IG) Below 1 V
      E1-7 (GRFG) - Body ground Power switch on (IG) Below 1 V
      E1-2 (GSN) - Body ground Power switch on (IG) Below 1 V
      E1-8 (GSNG) - Body ground Power switch on (IG) Below 1 V
      E1-3 (GCS) - Body ground Power switch on (IG) Below 1 V
      E1-9 (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.

    6. Turn the power switch off.

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

    8. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK GENERATOR RESOLVER

    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 connector E1 from the inverter with converter assembly.

    3. A01HUMVE01
      Text in Illustration
      *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 Switch Condition Specified Condition
      E1-1 (GRF) - E1-7 (GRFG) Power switch off 4.2 to 12.5 Ω
      E1-2 (GSN) - E1-8 (GSNG) Power switch off 9.8 to 20.1 Ω
      E1-3 (GCS) - E1-9 (GCSG) Power switch off 9.8 to 20.1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      E1-1 (GRF) or E1-7 (GRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-2 (GSN) or E1-8 (GSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-3 (GCS) or E1-9 (GCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

    4. 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. 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 connector E1 from the inverter with converter assembly.

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

    4. Turn the power switch on (IG).

    5. A01HUMVE02
      Text in Illustration
      *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 Switch Condition Specified Condition
      E1-4 (MRF) - Body ground Power switch on (IG) Below 1 V
      E1-11 (MRFG) - Body ground Power switch on (IG) Below 1 V
      E1-5 (MSN) - Body ground Power switch on (IG) Below 1 V
      E1-12 (MSNG) - Body ground Power switch on (IG) Below 1 V
      E1-6 (MCS) - Body ground Power switch on (IG) Below 1 V
      E1-13 (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.

    6. Turn the power switch off.

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

    8. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. CHECK MOTOR RESOLVER

    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 connector E1 from the inverter with converter assembly.

    3. A01HUMVE02
      Text in Illustration
      *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 Switch Condition Specified Condition
      E1-4 (MRF) - E1-11 (MRFG) Power switch off 4.2 to 12.5 Ω
      E1-5 (MSN) - E1-12 (MSNG) Power switch off 9.8 to 20.1 Ω
      E1-6 (MCS) - E1-13 (MCSG) Power switch off 9.8 to 20.1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      E1-4 (MRF) or E1-11 (MRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-5 (MSN) or E1-12 (MSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-6 (MCS) or E1-13 (MCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

    4. Connect the inverter with converter assembly connector.


    NG

    Click here

    OK

  8. CHECK CONNECTOR CONNECTION CONDITION (GENERATOR RESOLVER CONNECTOR)


    1. A01HT4O

      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. A01HSIA

      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. A01HT4O

      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)

    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 connector E1 from the inverter with converter assembly.

    3. A01HSKRE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)
      *b

      Front view of wire harness connector

      (to Generator Resolver)

      Disconnect the generator resolver connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      E1-1 (GRF) - E13-1 (GRF) Power switch off Below 1 Ω
      E1-7 (GRFG) - E13-5 (GRFG) Power switch off Below 1 Ω
      E1-2 (GSN) - E13-2 (GSN) Power switch off Below 1 Ω
      E1-8 (GSNG) - E13-6 (GSNG) Power switch off Below 1 Ω
      E1-3 (GCS) - E13-3 (GCS) Power switch off Below 1 Ω
      E1-9 (GCSG) - E13-7 (GCSG) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      E1-1 (GRF) or E13-1 (GRF) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-7 (GRFG) or E13-5 (GRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-2 (GSN) or E13-2 (GSN) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-8 (GSNG) or E13-6 (GSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-3 (GCS) or E13-3 (GCS) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-9 (GCSG) or E13-7 (GCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

      Tech Tips

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

    5. Connect the generator resolver connector.

    6. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Click here

  12. CHECK CONNECTOR CONNECTION CONDITION (MOTOR RESOLVER CONNECTOR)


    1. A01HSIA

      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)

    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 connector E1 from the inverter with converter assembly.

    3. A01HU2TE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)
      *b

      Front view of wire harness connector

      (to Motor Resolver)

      Disconnect the motor resolver connector.

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

      Standard Resistance (Check for Open)
      Tester Connection Switch Condition Specified Condition
      E1-4 (MRF) - E12-1 (MRF) Power switch off Below 1 Ω
      E1-11 (MRFG) - E12-4 (MRFG) Power switch off Below 1 Ω
      E1-5 (MSN) - E12-2 (MSN) Power switch off Below 1 Ω
      E1-12 (MSNG) - E12-5 (MSNG) Power switch off Below 1 Ω
      E1-6 (MCS) - E12-3 (MCS) Power switch off Below 1 Ω
      E1-13 (MCSG) - E12-6 (MCSG) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      Tester Connection Switch Condition Specified Condition
      E1-4 (MRF) or E12-1 (MRF) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-11 (MRFG) or E12-4 (MRFG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-5 (MSN) or E12-2 (MSN) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-12 (MSNG) or E12-5 (MSNG) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-6 (MCS) or E12-3 (MCS) - Body ground and other terminals Power switch off 1 MΩ or higher
      E1-13 (MCSG) or E12-6 (MCSG) - Body ground and other terminals Power switch off 1 MΩ or higher

      Tech Tips

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

    5. Connect the motor resolver connector.

    6. Connect the inverter with converter assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

    REPLACE HYBRID VEHICLE TRANSAXLE ASSEMBLY Click here