MOTOR GENERATOR CONTROL SYSTEM, Diagnostic DTC:P31241F, P312487

DTC Code DTC Name
P31241F Lost Communication between Drive Motor "A" and HV ECU Circuit Intermittent
P312487 Lost Communication between Drive Motor "A" and HV ECU Missing Message

DESCRIPTION

The motor generator control ECU, which is built into the inverter with converter assembly, controls the motor (MG2) based on commands from the hybrid vehicle control ECU assembly.

The motor generator control ECU (MG ECU) monitors communication data and detects malfunctions.

A communication error between the motor generator control ECU and hybrid vehicle control ECU assembly is detected.

DTC No. Detection Item DTC Detection Condition Trouble Area MIL Warning Indicate
P31241F Lost Communication between Drive Motor "A" and HV ECU Circuit Intermittent

Error in reception from hybrid vehicle control ECU assembly via serial communication (out of communication standard) detected when DTC P0C7917, P0D3319, P1C5D19 or P1C5F19 is stored.

(1 trip detection logic)

  • Wire harness or connector

  • Inverter with converter assembly

  • Hybrid vehicle control ECU assembly

 Does not come on

Master Warning Light:

Does not come on
P312487 Lost Communication between Drive Motor "A" and HV ECU Missing Message

Error in reception from hybrid vehicle control ECU assembly via serial communication (out of communication standard)

(1 trip detection logic)

  • Wire harness or connector

  • Inverter with converter assembly

  • Hybrid vehicle control ECU assembly

 Does not come on

Master Warning Light:

Comes on

CONFIRMATION DRIVING PATTERN

Tech Tips

After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.

Click here


  1. Connect the GTS to the DLC3.

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

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

  4. Turn the power switch off and wait for 2 minutes or more.

  5. Turn the power switch on (IG) and turn the GTS on.

  6. With power switch on (IG) and wait for 2 minutes or more.

  7. Enter the following menus: Powertrain / Motor Generator / Utility / All Readiness.

  8. Check the DTC judgment result.

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform driving pattern again.

WIRING DIAGRAM

Refer to the wiring diagram for the Inverter Low-voltage Circuit.

Click here

CAUTION / NOTICE / HINT

CAUTION:


  • B004BJX

    Before the following operations are conducted, take precautions to prevent electric shock by turning the power switch off, wearing insulated gloves, and removing the service plug grip from HV battery.


    • Inspecting the high-voltage system

    • Disconnecting the low voltage connector of the inverter with converter assembly

    • Disconnecting the low voltage connector of the HV battery

  • B004C5R

    To prevent electric shock, make sure to remove the service plug grip to cut off the high voltage circuit before servicing the vehicle.

  • B0049VM

    After removing the service plug grip from the HV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system.

  • B004AZGC06
    *a Without waiting for 10 minutes

    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. CLEAR DTC


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Powertrain / Motor Generator / Trouble Codes.

    5. Clear the DTCs.


      Powertrain > Motor Generator > Clear DTCs

    6. Turn the power switch off.

      Result
      Proceed to
      NEXT

    NEXT

  2. CHECK DIAGNOSIS RELATED INFORMATION AND DTC OUTPUT (MOTOR GENERATOR CONTROL)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Enter the following menus: Powertrain / Motor Generator / Utility / Diagnosis Related Information.


      Powertrain > Motor Generator > Utility
      Tester Display
      Diagnosis Related Information

    4. Enter the following menus: Powertrain / Motor Generator / Trouble Codes.


      Powertrain > Motor Generator > Trouble Codes

    5. Check for DTCs.

      Result
      Result Proceed to
      P31241F or P312487 is listed in Diagnosis Related Information or DTC P31241F or P312487 is output. A
      P31241F and P312487 is not listed in Diagnosis Information and DTC P31241F and P312487 is not output. B

    6. Turn the power switch off.


    B

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  3. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY (CHECK WAVEFORM)


    1. Connect an oscilloscope between the hybrid vehicle control ECU assembly terminals specified in the following table.

    2. Turn the power switch on (IG).

    3. B004CAQC02
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

      Measure the waveform.

      Item Contents
      Tester Connection

      CH1: A22-28 (HMCH) - P64-6 (E1)

      CH2: A22-20 (HMCL) - P64-6 (E1)
      Equipment Setting 1 V/DIV., 200 μs./DIV.
      Condition Power switch on (IG)
      Result
      Result Proceed to
      The waveform appears as shown in the illustration. A
      The waveform differs from the one shown in the illustration. B

      Tech Tips


      • Perform this inspection with the connector connected.

      • If pulses are generated, the shape of the waveform can be assumed to be normal.

      • The shape of the waveform may vary according to communication conditions.

    4. Turn the power switch off.


    A

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

    B

  4. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU ASSEMBLY - INVERTER WITH CONVERTER 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. Disconnect the A22 hybrid vehicle control ECU assembly connector.

    3. Disconnect the A23*1 or A24*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

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

    5. Turn the power switch on (IG).

    6. B004BIEC14
      *A for LHD
      *B for RHD
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)
      *b

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      for LHD
      Tester Connection Condition Specified Condition
      A23-5 (HMCH) or A22-28 (HMCH) - Body ground and other terminals Power switch on (IG) Below 1 V
      A23-6 (HMCL) or A22-20 (HMCL) - Body ground and other terminals Power switch on (IG) Below 1 V
      for RHD
      Tester Connection Condition Specified Condition
      A24-5 (HMCH) or A22-28 (HMCH) - Body ground and other terminals Power switch on (IG) Below 1 V
      A24-6 (HMCL) or A22-20 (HMCL) - Body ground and other terminals Power switch on (IG) Below 1 V

      Note

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

    7. Turn the power switch off.

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

      Standard Resistance (Check for Open)
      for LHD
      Tester Connection Condition Specified Condition
      A23-5 (HMCH) - A22-28 (HMCH) Power switch off Below 1 Ω
      A23-6 (HMCL) - A22-20 (HMCL) Power switch off Below 1 Ω
      for RHD
      Tester Connection Condition Specified Condition
      A24-5 (HMCH) - A22-28 (HMCH) Power switch off Below 1 Ω
      A24-6 (HMCL) - A22-20 (HMCL) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      for LHD
      Tester Connection Condition Specified Condition
      A23-5 (HMCH) or A22-28 (HMCH) - Body ground and other terminals Power switch off 10 kΩ or higher
      A23-6 (HMCL) or A22-20 (HMCL) - Body ground and other terminals Power switch off 10 kΩ or higher
      for RHD
      Tester Connection Condition Specified Condition
      A24-5 (HMCH) or A22-28 (HMCH) - Body ground and other terminals Power switch off 10 kΩ or higher
      A24-6 (HMCL) or A22-20 (HMCL) - Body ground and other terminals Power switch off 10 kΩ or higher

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

    10. Reconnect the A23*1 or A24*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

    11. Reconnect the A22 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK INVERTER WITH CONVERTER ASSEMBLY


    1. Disconnect the A22 hybrid vehicle control ECU assembly connector.

    2. B004BBAC37
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A22-28 (HMCH) - A22-20 (HMCL) Power switch off 80 to 170 Ω

    3. Reconnect the A22 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

    NG

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here