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 EV control ECU and inverter.

Related Parts Check
Area Inspection Step
Inverter +B low-voltage power source system check Check for inverter overcurrent malfunction. 1, 2
Communication malfunction between EV control ECU and MG-ECU inside inverter with converter assembly Check for inverter overcurrent malfunction due to communication malfunction. 3, 4
Check for short to ground in inverter +B low-voltage power source system - 5, 6, 7

WIRING DIAGRAM

B000ZW6E07

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:


  • B006JFB
    B006JM4

    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 grips from both FC stack assembly and EV battery.


    • Inspecting the high-voltage system

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

    • Disconnecting the low voltage connector of the EV battery

    • Disconnecting the low voltage connector of the FC stack assembly

    • Disconnecting the low voltage connector of the FC converter assembly

      Tech Tips

      No removal order is specified for the service plug grips of the FC stack assembly and EV battery.

  • B006JBZ

    After removing the service plug grip from the EV battery, put it in your pocket to prevent other technicians from accidentally reconnecting it while you are working on the high-voltage system. After removing the service grip from the FC stack assembly, store it in a safe location and use the "HIGH-VOLTAGE, DO NOT TOUCH" sign to notify other technicians that you are working on the high-voltage system.

  • B000ZMTC04
    *a Without waiting for 10 minutes

    After removal of the service plug grips of both FC stack assembly and EV battery, wait for at least 10 minutes before touching the high-voltage connectors and 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

    At least 10 minutes are necessary to discharge the high-voltage capacitors inside the inverter with converter assembly and FC stack 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.

    Click here

  • When reinstalling the service plug grip to the FC stack assembly or the EV battery, slide the lever of the service plug until the letters "UNLOCK" are completely hidden, and insert it firmly.

    Click here

  • When the vehicle is parked with the power switch off, if the FC control ECU judges that the FC stack temperature will go below 0°C (32°F), it activates the FC air compressor, hydrogen pump and FC cooling water pump for a maximum of 180 seconds and drains water from the FC stack assembly. When performing inspection or repairs with the power switch off (not on (IG) or on (READY)), disconnect the cable from the negative (-) auxiliary battery terminal before performing work (If the auxiliary battery voltage is needed to conduct inspection, warm up the FC system beforehand).

PROCEDURE


  1. CHECK FUSE (PCU)


    1. B000ZFHC04
      *1 Motor Compartment Relay Block
      *2 PCU Fuse

      Remove the PCU fuse from the motor compartment relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      PCU fuse terminal Always Below 1 Ω

    3. Install the PCU fuse.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - PCU 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 to FC stack assembly and EV battery.

      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 inverter with converter assembly connector.

      Click here

    3. B000ZLXC19
      *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
      Tester Connection Condition Specified Condition
      A10-10 (GND1) - Body ground Power switch off Below 1 Ω
      A10-11 (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
      Tester Connection Condition Specified Condition
      A10-30 (+B) - Body ground Power switch on (IG) Same as auxiliary battery voltage
      A10-31 (+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.

    9. Reconnect the inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE POWER SOURCE CIRCUIT

    OK

  3. CHECK HARNESS AND CONNECTOR (EV CONTROL ECU - INVERTER WITH CONVERTER ASSEMBLY)

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed to FC stack assembly and EV battery.

      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 inverter with converter assembly connector.

    3. Disconnect the EV control ECU connector.

    4. B000ZTYC02
      *a

      Front view of wire harness connector

      (to Inverter with Converter Assembly)
      *b

      Rear view of wire harness connector

      (to EV Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A10-9 (HTM+) - A27-24 (HTM+) Power switch off Below 1 Ω
      A10-20 (HTM-) - A27-25 (HTM-) Power switch off Below 1 Ω
      A10-8 (MTH+) - A27-23 (MTH+) Power switch off Below 1 Ω
      A10-19 (MTH-) - A27-22 (MTH-) Power switch off Below 1 Ω
      A10-26 (REQ+) - A27-31(REQ+) Power switch off Below 1 Ω
      A10-37 (REQ-) - A27-30 (REQ-) Power switch off Below 1 Ω
      A10-7 (CLK+) - A27-33 (CLK+) Power switch off Below 1 Ω
      A10-18 (CLK-) - A27-32 (CLK-) Power switch off Below 1 Ω
      A10-9 (HTM+) or A27-24 (HTM+) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-20 (HTM-) or A27-25 (HTM-) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-8 (MTH+) or A27-23 (MTH+) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-19 (MTH-) or A27-22 (MTH-) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-26 (REQ+) or A27-31(REQ+) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-37 (REQ-) or A27-30 (REQ-) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-7 (CLK+) or A27-33 (CLK+) - Body ground and other terminals Power switch off 10 kΩ or higher
      A10-18 (CLK-) or A27-32 (CLK-) - 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
      Tester Connection Condition Specified Condition
      A10-9 (HTM+) or A27-24 (HTM+) - Body ground Power switch on (IG) Below 1 V
      A10-20 (HTM-) or A27-25 (HTM-) - Body ground Power switch on (IG) Below 1 V
      A10-8 (MTH+) or A27-23 (MTH+) - Body ground Power switch on (IG) Below 1 V
      A10-19 (MTH-) or A27-22 (MTH-) - Body ground Power switch on (IG) Below 1 V
      A10-26 (REQ+) or A27-31(REQ+) - Body ground Power switch on (IG) Below 1 V
      A10-37 (REQ-) or A27-30 (REQ-) - Body ground Power switch on (IG) Below 1 V
      A10-7 (CLK+) or A27-33 (CLK+) - Body ground Power switch on (IG) Below 1 V
      A10-18 (CLK-) or A27-32 (CLK-) - Body ground Power switch on (IG) Below 1 V

      Note

      Turning the power switch on (IG) with the EV control ECU 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.

    10. Reconnect the EV control ECU connector.

    11. Reconnect the inverter with converter assembly connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK EV CONTROL ECU


    1. Disconnect the EV control ECU connector.

    2. B000ZFTC06
      *a

      Component without harness connected

      (EV Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A27-24 (HTM+) - A27-25 (HTM-) Power switch off 80 to 170 Ω
      A27-23 (MTH+) - A27-22 (MTH-) Power switch off 80 to 170 Ω
      A27-31 (REQ+) - A27-30 (REQ-) Power switch off 80 to 170 Ω
      A27-33 (CLK+) - A27-32 (CLK-) Power switch off 80 to 170 Ω

    3. Reconnect the EV control ECU connector.

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE EV CONTROL ECU Click here

  5. CHECK HARNESS AND CONNECTOR (INVERTER WITH CONVERTER ASSEMBLY - PCU FUSE)

    CAUTION:

    Be sure to wear insulated gloves.


    1. Check that the service plug grip is not installed to FC stack assembly and EV battery.

      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 inverter with converter assembly connector.

      Click here

    3. B000ZLXC20
      *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
      Tester Connection Condition Specified Condition
      A10-30 (+B) - Body ground Power switch off 10 kΩ or higher
      A10-31 (+B2) - Body ground Power switch off 10 kΩ or higher

    4. Reconnect the inverter with converter assembly connector.

      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 (PCU)

  7. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (PCU)