HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A7A-344

DTC Code DTC Name
P0A7A-344 Generator Inverter Performance

DESCRIPTION

For a description of the inverter, Click here.

If the MG1 torque execution value does not correspond to the torque command value from the MG ECU to MG1, the hybrid vehicle control ECU will store this DTC.

DTC No. INF Code DTC Detection Condition Trouble Area
P0A7A 344 MG1 torque execution monitoring malfunction
  • Hybrid vehicle transmission assembly

  • Inverter with converter assembly

  • Generator cable

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. Select the following menu items: Powertrain / Hybrid Control / Trouble Codes.

    4. Check if DTCs are output.

      Result
      Result Proceed to
      P0A7A-344 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
      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, 279, 287, 503, 504, 505, 506, 586, 806, 807, 808 Drive Motor "A" Inverter Performance
      P0A7A-325, 517, 518, 809, 810, 811 Generator Inverter Performance
      P0A94-547, 548, 549, 554, 555, 556, 585, 587, 589, 590 DC / DC Converter Performance
      P0AA6 (all INF codes) *1 Hybrid Battery Voltage System Isolation Fault
      P0C76-523 Hybrid Battery System Discharge Time Too Long
      P3004-132 Power Cable Malfunction
      P3233-750 Short to B+ in Blocking of HV Gate Connection
      P3240-443 DC / DC Converter Control Circuit

      Tech Tips


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

      • P0A7A-344 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.


    B
    A
  2. CHECK CONNECTOR CONNECTION CONDITION (INVERTER WITH CONVERTER ASSEMBLY CONNECTOR)

    CAUTION:

    Be sure to wear insulated gloves.


    1. Turn the power switch off.

    2. Remove the service plug grip. Click here

      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.

    3. 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
    OK
  3. CHECK INVERTER WITH CONVERTER ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)

    CAUTION:

    Be sure to wear insulated gloves.


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

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


      • For LHD vehicles, use the following procedures Click here.

      • For RHD vehicles, use the following procedures Click here.

      Note

      Lift the inverter terminal cover horizontally so that it does not tilt. Failure to do so may break the inverter cover guide pins.

      A01H1SOE01
    3. Check that the bolts for the generator cable are tightened to the specified torque, the generator cable is connected securely, and there are no contact problems.

      A01H0UWE01
      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 generator 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

    B
    C
    A
  4. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (MG1)

    CAUTION:

    Be sure to wear insulated gloves.


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

    2. Disconnect the generator cable and motor cable from the inverter with converter assembly.

      Tech Tips

      For the removal and installation procedures related to the generator cable and motor cable, Click here.

    3. Check MG1 for an interphase short using a milliohmmeter.

      A01H1D2E01

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

        Tech Tips

        If the MG1 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
        LHD
        Tester Connection Switch Condition Specified Condition
        U - V Power switch off 32.4 to 35.8 mΩ
        V - W Power switch off 31.3 to 34.6 mΩ
        W - U Power switch off 31.4 to 34.7 mΩ
        RHD
        Tester Connection Switch Condition Specified Condition
        U - V Power switch off 32.3 to 35.7 mΩ
        V - W Power switch off 31.2 to 34.5 mΩ
        W - U Power switch off 31.3 to 34.6 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)

    4. 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
      U - Body ground and shielded wire ground Power switch off 100 MΩ or higher
      V - Body ground and shielded wire ground Power switch off 100 MΩ or higher
      W - Body ground and shielded wire ground Power switch off 100 MΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B
    C
    A
  5. CHECK HYBRID VEHICLE TRANSMISSION ASSEMBLY (GENERATOR CABLE CONNECTION CONDITION)


    1. A01H0G5

      Remove the hybrid vehicle transmission assembly Click here.

    2. Check that the bolts for the generator cable are tightened to the specified torque, the generator 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. Check for arc marks at the bolts for the generator 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

    B
    C
    A
  6. CHECK GENERATOR CABLE


    1. Remove the generator cable from the hybrid vehicle transmission assembly. Click here

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

      A01H1PIE01

      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
      U - Shielded wire ground Power switch off 100 MΩ or higher
      V - Shielded wire ground Power switch off 100 MΩ or higher
      W - Shielded wire ground Power switch off 100 MΩ or higher
      U - V Power switch off 100 MΩ or higher
      V - W Power switch off 100 MΩ or higher
      W - U Power switch off 100 MΩ or higher
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance
      Tester Connection Condition Specified Condition
      U - U Power switch off 1 Ω or less
      V - V Power switch off 1 Ω or less
      W - W Power switch off 1 Ω or less

    NG
    OK