HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A79-704

DTC Code DTC Name
P0A79-704 Drive Motor "B" Inverter Performance

DESCRIPTION

For a description of the inverter, Click here.

If the MGR torque execution value does not correspond to the torque command value from the MG ECU to MGR , the power management control ECU (HV CPU) will store this DTC.

Tech Tips

The term "drive motor B" indicates MGR.

DTC No. INF Code DTC Detection Condition Trouble Area
P0A79 704 MGR torque execution monitoring malfunction

  • Inverter with converter assembly

  • Rear traction motor with transaxle assembly

  • NO.3 wire frame

  • Extension wire assembly

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A79-136 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
      P0A79-704 only is output. A
      Any of the following DTCs are also output. B
      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 (except for INF code 390)*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
      P0A78-118, 119, 120, 266, 267, 279, 287, 503, 504, 505, 506, 586, 806, 807, 808 Drive Motor "A" Inverter Performance
      P0A79-693, 694, 695, 812, 813, 814, 703, 716 Drive Motor "B" Inverter Performance
      P0A7A-325, 517, 518, 809, 810, 811, 522 Generator Inverter Performance
      P0A94-124, 125, 126, 547, 548, 549, 554, 555, 556, 585, 587, 589, 590 DC / DC Converter Performance
      P0AA6 (all INF codes)*1 Hybrid Battery Voltage System Isolation Fault
      P3004-132 Power Cable Malfunction
      P3233-750 Short to B+ in Blocking of HV Gate Connection
      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.

      • P0A79-704 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

  2. 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

  3. CHECK INVERTER WITH CONVERTER ASSEMBLY (REAR MOTOR CABLE CONNECTION CONDITION)

    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. A01NE6E

      Remove the inverter terminal cover from the inverter with converter assembly.

    3. A01NEMY

      Check that the bolts for the rear motor cable are tightened to the specified torque, the rear motor cable is connected securely, and there are no contact problems.

      Specified Condition
      T=8.0 N*m {82 kgf*cm, 71 in.*lbf}

      Note

      Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

    4. Check for arc marks at the bolts for the rear motor cable.

      Result
      Result Proceed to
      The terminals are connected securely and there are no contact problems. There are no arc marks. A
      The terminals are not connected securely and there is a contact problem. There are arc marks. B
      The terminals are not connected securely and there is a contact problem. There are no arc marks. C
      The terminals are connected securely and there are no contact problems. There are arc marks. B

    5. Install the inverter terminal cover.


    B

    REPLACE MALFUNCTIONING PARTS

    C

    CONNECT SECURELY

    A

  4. CHECK REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY (MGR)

    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. A01NE6E

      Remove the inverter terminal cover from the inverter with converter assembly.

    3. A01NEMY

      Disconnect the rear motor cable from the inverter with converter assembly.

    4. A01NCLKE05
      Text in Illustration
      *1 Rear Motor Cable
      *2 Shielded Ground

      Check MGR for an interphase short using a milliohmmeter.


      1. Using a milliohmmeter, measure the resistance according to the value(s) in the table below.

        Tech Tips

        If the MGR temperature is high, the resistance will vary greatly from the specification. Therefore, measure the resistance at least 8 hours after the vehicle is stopped.

        Standard Resistance
        Tester Connection Switch Condition Specified Condition
        g4-3 (R-U) - g4-2 (R-V) Power switch off 162 to 176 mΩ
        g4-2 (R-V) - g4-1 (R-W) Power switch off 162 to 176 mΩ
        g4-1 (R-W) - g4-3 (R-U) Power switch off 162 to 176 mΩ

        Tech Tips

        To correct the variation of the measured resistance due to temperature, use the following formula to calculate the resistance at 20°C (68° F).


        • R20 = Rt / {1 + 0.00393 X (T - 20)}

        The calculation is based on the following:


        • R20: Resistance at 20°C (68° F) (mΩ)

        • Rt: Measured resistance (mΩ)

        • T: Temperature when the resistance is measured (° C)

    5. Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

      Note

      Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

      Standard resistance
      Tester Connection Switch Condition Specified Condition
      g4-3 (R-U) - Body ground and shielded ground Power switch off 100 MΩ or higher
      g4-2 (R-V) - Body ground and shielded ground Power switch off 100 MΩ or higher
      g4-1 (R-W) - Body ground and shielded ground Power switch off 100 MΩ or higher

    6. Connect the rear motor cable.

    7. Install the inverter terminal cover.


    NG

    Click here

    OK

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

  5. CHECK REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY (REAR MOTOR CABLE CONNECTION CONDITION)

    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. A01NE5V

      Check that the bolts for the rear motor cable are tightened to the specified torque, the rear motor cable is connected securely, and there are no contact problems.

      Specified Condition
      T=8.0 N*m{82 kgf*cm, 71 in.*lbf}

      Note

      Make sure that the tightening torque of the bolts is between 6.4 and 9.6 N*m (65 and 98 kgf*cm, 57 and 85 in.*lbf).

    3. Disconnect the rear motor cable from the rear traction motor with transaxle assembly.

    4. Check for arc marks at the bolts for the rear motor cable.

      Result
      Result Proceed to
      The terminals are connected securely and there are no contact problems. There are no arc marks. A
      The terminals are not connected securely and there is a contact problem. There are arc marks. B
      The terminals are not connected securely and there is a contact problem. There are no arc marks. C
      The terminals are connected securely and there are no contact problems. There are arc marks. B

    5. Connect the rear motor cable.


    B

    REPLACE MALFUNCTIONING PARTS

    C

    CONNECT SECURELY

    A

  6. CHECK NO.3 WIRE FRAME (REAR MOTOR CABLE)

    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. A01NE6E

      Remove the inverter terminal cover from the inverter with converter assembly.

    3. A01NEMY

      Disconnect the rear motor cable from the inverter with converter assembly.

    4. A01NE5V

      Disconnect the rear motor cable from the rear traction motor with transaxle assembly.

    5. A01NDPUE02
      Text in Illustration
      *1 Rear Motor Cable
      *2 Shielded Ground

      Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

      Note

      Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      g4-3 (R-U) - Body ground and shielded ground Power switch off 10 MΩ or higher
      g4-2 (R-V) - Body ground and shielded ground Power switch off 10 MΩ or higher
      g4-1 (R-W) - Body ground and shielded ground Power switch off 10 MΩ or higher

      Note

      Wrap the terminals of three-phase AC cable with insulating tape to avoid them coming into contact with body ground.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      g4-3 (R-U) - g5-3 (R-U) Power switch off Below 1 Ω
      g4-2 (R-V) - g5-2 (R-V) Power switch off Below 1 Ω
      g4-1 (R-W) - g5-1 (R-W) Power switch off Below 1 Ω
      g4-3 (R-U) - g5-2 (R-V) Power switch off 10 kΩ or higher
      g4-2 (R-V) - g5-1 (R-W) Power switch off 10 kΩ or higher
      g4-1 (R-W) - g5-3 (R-U) Power switch off 10 kΩ or higher

    7. Connect the rear motor cable to the rear traction motor with transaxle assembly.

    8. Connect the rear motor cable to the inverter with converter assembly.

    9. Install the inverter terminal cover.


    NG

    REPLACE NO.3 WIRE FRAME Click here

    OK

  7. CHECK EXTENSION WIRE ASSEMBLY

    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. Remove the rear traction motor with transaxle assembly.

    3. Remove the extension wire assembly from the rear traction motor with transaxle assembly.

    4. A01NFEFE03
      Text in Illustration
      *1 Extension Wire Assembly
      *2 Shielded Ground

      Using a megohmmeter set to 500 V, measure the resistance according to the value(s) in the table below.

      Note

      Be sure to set the megohmmeter to 500 V when performing this test. Using a setting higher than 500 V can result in damage to the component being inspected.

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      R-U - Body ground and shielded ground Power switch off 10 MΩ or higher
      R-V - Body ground and shielded ground Power switch off 10 MΩ or higher
      R-W - Body ground and shielded ground Power switch off 10 MΩ or higher

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      R-U - R-U Power switch off Below 1 Ω
      R-V - R-V Power switch off Below 1 Ω
      R-W - R-W Power switch off Below 1 Ω
      R-U - R-V Power switch off 10 kΩ or higher
      R-V - R-W Power switch off 10 kΩ or higher
      R-W - R-U Power switch off 10 kΩ or higher

    6. Install the extension wire.

    7. Install the rear traction motor with transaxle assembly.


    NG

    REPLACE EXTENSION WIRE ASSEMBLY Click here

    OK

    REPLACE REAR TRACTION MOTOR WITH TRANSAXLE ASSEMBLY Click here