HYBRID CONTROL SYSTEM Inverter Low-voltage Circuit

DESCRIPTION

The cause of the malfunction may be the low-voltage circuit.

Check whether there is an open circuit in the inverter +B low-voltage power source system or a problem in the communication between the hybrid vehicle control ECU assembly and inverter.

Related Parts Check
Area Inspection
Inverter +B low-voltage power source system check Check for inverter overcurrent malfunction.
Communication malfunction between hybrid vehicle control ECU assembly and MG-ECU inside inverter with converter assembly Check for inverter overcurrent malfunction due to communication malfunction.
Check for short to ground in inverter +B low-voltage power source system -

WIRING DIAGRAM

B004TXOE18

CAUTION / NOTICE / HINT

This step is referenced from the procedures for each DTC.

If the inspection results below are normal, perform the next procedure for the referenced DTC.

CAUTION:


  • B004STG

    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

  • B004Y5N

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

  • B004SX1

    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.

  • B004W3JC06
    *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.

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    Tech Tips

    Waiting for at least 10 minutes is required to discharge the high-voltage capacitor inside the inverter with converter assembly.

  • Make sure to insulate the high-voltage connectors and terminals of the HV battery with insulating tape after removing it.

    If the HV battery stored without insulating the connectors and terminals, electric shock or fire may result.

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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Tech Tips

After the power switch is turned off, even if the cable is disconnected from the negative (-) auxiliary battery terminal, voltage will continue to be supplied to terminal +B and terminal +B2 of the inverter with converter assembly by the inverter battery (backup power supply) for approximately 2 minutes.

PROCEDURE


  1. CHECK FUSE (IGCT NO.2)


    1. B004WBOC02
      *1 No. 2 Luggage Room Relay Block
      *2 IGCT NO.2 Fuse

      Remove the IGCT NO.2 fuse from the No. 2 luggage room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IGCT NO.2 fuse terminal Always Below 1 Ω

    3. Install the IGCT NO.2 fuse.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - IGCT NO.2 FUSE) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY POWER SOURCE CIRCUIT)

    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 A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

    3. B004TPFC46
      *A for LHD
      *B for RHD
      *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
      for LHD:
      Tester Connection Condition Specified Condition
      A94-30 (GND1) - Body ground Power switch off Below 1 Ω
      A94-31 (GND2) - Body ground Power switch off Below 1 Ω
      for RHD:
      Tester Connection Condition Specified Condition
      A78-30 (GND1) - Body ground Power switch off Below 1 Ω
      A78-31 (GND2) - Body ground Power switch off Below 1 Ω

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

    5. Turn the power switch on (IG).

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

      Standard Voltage
      for LHD:
      Tester Connection Condition Specified Condition
      A94-10 (+B) - Body ground Power switch on (IG) Same as auxiliary battery voltage
      A94-11 (+B2) - Body ground Power switch on (IG) Same as auxiliary battery voltage
      for RHD:
      Tester Connection Condition Specified Condition
      A78-10 (+B) - Body ground Power switch on (IG) Same as auxiliary battery voltage
      A78-11 (+B2) - Body ground Power switch on (IG) Same as auxiliary battery voltage

      Note

      Turning the power switch on (IG) with the inverter with converter assembly connector disconnected causes other DTCs to be stored. Clear the DTCs after performing this inspection.

    7. Turn the power switch off.

    8. Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.

    9. Reconnect the A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT

    OK

  3. 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 A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

    3. Disconnect the A77 hybrid vehicle control ECU assembly connector.

    4. B004Y0NC27
      *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 resistance according to the value(s) in the table below.

      Standard Resistance (Check for Open)
      for LHD:
      Tester Connection Condition Specified Condition
      A94-5 (HMCH) - A77-28 (HMCH) Power switch off Below 1 Ω
      A94-6 (HMCL) - A77-20 (HMCL) Power switch off Below 1 Ω
      for RHD:
      Tester Connection Condition Specified Condition
      A78-5 (HMCH) - A77-28 (HMCH) Power switch off Below 1 Ω
      A78-6 (HMCL) - A77-20 (HMCL) Power switch off Below 1 Ω
      Standard Resistance (Check for Short)
      for LHD:
      Tester Connection Condition Specified Condition
      A94-5 (HMCH) or A77-28 (HMCH) - Body ground and other terminals Power switch off 10 kΩ or higher
      A94-6 (HMCL) or A77-20 (HMCL) - Body ground and other terminals Power switch off 10 kΩ or higher
      for RHD:
      Tester Connection Condition Specified Condition
      A78-5 (HMCH) or A77-28 (HMCH) - Body ground and other terminals Power switch off 10 kΩ or higher
      A78-6 (HMCL) or A77-20 (HMCL) - Body ground and other terminals Power switch off 10 kΩ or higher

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

    6. Turn the power switch on (IG).

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

      Standard Voltage
      for LHD:
      Tester Connection Condition Specified Condition
      A94-5 (HMCH) or A77-28 (HMCH) - Body ground and other terminals Power switch on (IG) Below 1 V
      A94-6 (HMCL) or A77-20 (HMCL) - Body ground and other terminals Power switch on (IG) Below 1 V
      for LHD:
      Tester Connection Condition Specified Condition
      A78-5 (HMCH) or A77-28 (HMCH) - Body ground and other terminals Power switch on (IG) Below 1 V
      A78-6 (HMCL) or A77-20 (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.

    8. Turn the power switch off.

    9. Disconnect the cable from the negative (-) auxiliary battery terminal and wait for 2 minutes or more.

    10. Reconnect the A77 hybrid vehicle control ECU assembly connector.

    11. Reconnect the A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY


    1. Disconnect the A77 hybrid vehicle control ECU assembly connector.

    2. B004ROCC04
      *a

      Component without harness connected

      (Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A77-28 (HMCH) - A77-20 (HMCL) Power switch off 80 to 170 Ω

    3. Reconnect the A77 hybrid vehicle control ECU assembly connector.

      Result
      Proceed to
      OK
      NG

    OK

    INVERTER LOW-VOLTAGE CIRCUIT NORMAL (PERFORM NEXT STEP FOR REFERENCED DTC)

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here

  5. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - IGCT NO.2 FUSE)

    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 A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

    3. B004TPFC47
      *A for LHD
      *B for RHD
      *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
      for LHD:
      Tester Connection Condition Specified Condition
      A94-10 (+B) - Body ground Power switch off 10 kΩ or higher
      A94-11 (+B2) - Body ground Power switch off 10 kΩ or higher
      for RHD:
      Tester Connection Condition Specified Condition
      A78-10 (+B) - Body ground Power switch off 10 kΩ or higher
      A78-11 (+B2) - Body ground Power switch off 10 kΩ or higher

    4. Reconnect the A94*1, A78*2 inverter with converter assembly connector.


      • *1: for LHD

      • *2: for RHD

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

    OK

  6. REPLACE INVERTER WITH CONVERTER ASSEMBLY

    Click here

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT NO.2)

  7. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT NO.2)