HYBRID CONTROL SYSTEM, Diagnostic DTC:P0A09-591

DTC Code DTC Name
P0A09-591 DC / DC Converter Status Circuit Low Input

DESCRIPTION

The hybrid vehicle converter (DC/DC converter) controls output voltage (12 V) based on duty ratio signals sent from the power management control ECU (HV CPU) .

DTC No. INF Code DTC Detection Condition Trouble Area
P0A09 591 Hybrid vehicle converter voltage switching (VLO) signal circuit malfunction (Open or short to GND)

  • Wire harness or connector

  • Inverter with converter assembly

  • Power management control ECU

WIRING DIAGRAM

A01NGL4E01

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 CONNECTOR CONNECTION CONDITION (POWER MANAGEMENT CONTROL ECU CONNECTOR)


    1. Check the connections of the power management control ECU connectors.

      A01NF3IE01
      Text in Illustration
      *1 for LHD *2 for RHD
      OK
      The connectors are connected securely and there are no contact problems.

    NG

    CONNECT SECURELY

    OK

  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 POWER MANAGEMENT CONTROL ECU (CHECK WAVEFORM)


    1. Turn the power switch on (IG).

    2. A01NECNE01
      Text in Illustration
      *1

      Component with harness connected

      (Power Management Control ECU)

      Connect an oscilloscope between the power management control ECU terminals specified in the table below, and measure the waveform.

      Item Content
      Terminal A80-11 (VLO) - F97-6 (E1)
      Equipment Setting 5V/DIV., 50ms/DIV.
      Condition Power switch on (IG)
      OK
      The waveform appears as shown in the illustration.

      Tech Tips


      • Perform this inspection with the power management control ECU connector connected.

    3. Turn the power switch off.


    NG

    CHECK POWER MANAGEMENT CONTROL ECU Click here

    OK

  4. CLEAR DTC


    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. Clear DTCs and freeze frame data.


    NEXT

  5. CHECK DTC OUTPUT (HV)


    1. Turn the power switch on (READY).

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

    3. Check if DTCs are output.

      Result
      Result Proceed to
      DTC P0A09-591 is not output. A
      DTC P0A09-591 is output again. for LHD B
      for RHD C

    4. Turn the power switch off.


    B

    REPLACE POWER MANAGEMENT CONTROL ECU (for LHD) Click here

    C

    REPLACE POWER MANAGEMENT CONTROL ECU (for RHD) Click here

    A

  6. CHECK FOR INTERMITTENT PROBLEMS


    1. Check for intermittent problems Click here.

      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    B

    REPLACE POWER MANAGEMENT CONTROL ECU (for RHD) Click here

    C

    REPAIR OR REPLACE MALFUNCTIONING PARTS, COMPONENT AND AREA

    A

    REPLACE POWER MANAGEMENT CONTROL ECU (for LHD) Click here

  7. CHECK POWER MANAGEMENT CONTROL ECU

    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 A79 connector from the inverter with converter assembly.

    3. A01NFV3E13
      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
      Tester Connection Switch Condition Specified Condition
      A79-4 (VLO) - Body ground Power switch off 370 to 430 kΩ

    4. Connect the inverter with converter assembly connector.


    NG

    CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER - POWER MANAGEMENT CONTROL ECU) Click here

    OK

    REPLACE INVERTER WITH CONVERTER ASSEMBLY Click here

  8. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER - POWER MANAGEMENT CONTROL ECU)


    1. Disconnect the A79 connector from the inverter with converter assembly.

    2. Disconnect the A80 connector from the power management control ECU.

    3. A01NEUQE02
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Inverter with Converter Assembly)
      *2

      Rear view of wire harness connector

      (to Power Management Control ECU)

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      A79-4 (VLO) - A80-11 (VLO) Power switch off Below 1 Ω
      A79-4 (VLO) or A80-11 (VLO) - Body ground and other terminals Power switch off 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    4. Connect the inverter with converter assembly connector.

    5. Connect the power management control ECU connector.


    B

    REPLACE POWER MANAGEMENT CONTROL ECU (for RHD) Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    A

    REPLACE POWER MANAGEMENT CONTROL ECU (for LHD) Click here