HYBRID BATTERY SYSTEM ECU Power Source Circuit

DESCRIPTION

If the power switch is on (IG), the hybrid vehicle control ECU applies current to the MREL terminal to turn the IGCT relay on. This supplies power to the IGCT terminals.

WIRING DIAGRAM

B006IPRE02
*a IGCT SCENE Relay
*b IGCT NO.2
*c ERTH
*d t14 Battery ECU Assembly

CAUTION / NOTICE / HINT

CAUTION:


  • B006HUP

    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

    • Disconnecting the low voltage connector of the electric vehicle charger assembly

    • Disconnecting the low voltage connector of the solar energy control unit

  • B006IQP

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

  • B006HQC

    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.

  • B006IVPC02
    *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 and the electric vehicle charger 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

PROCEDURE


  1. CHECK BATTERY ECU ASSEMBLY (IGCT VOLTAGE)

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.


    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. Remove the upper hybrid battery cover sub-assembly.

      Click here

    3. B006J82N02

      Disconnect the t14 battery ECU assembly connector.

      Note

      Before disconnecting the connector, check that it is not loose or disconnected.

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

    5. Turn the power switch on (IG).

    6. B006I6MC59
      *a

      Front view of wire harness connector

      (to Battery ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      t14-24 (IGCT) - Body ground Power switch on (IG) 11 to 14 V

    7. Turn the power switch off.

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

    9. Reconnect the t14 battery ECU assembly connector.

    10. Install the upper hybrid battery cover sub-assembly.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK FUSE (IGCT NO. 2) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (BATTERY ECU ASSEMBLY - BODY GROUND)

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.


    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. Remove the upper hybrid battery cover sub-assembly.

      Click here

    3. B006J82N02

      Disconnect the t14 battery ECU assembly connector.

      Note

      Before disconnecting the connector, check that it is not loose or disconnected.

    4. B006I6MC60
      *a

      Front view of wire harness connector

      (to Battery ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      t14-9 (GND) - Body ground Always Below 1 Ω
      t14-29 (GND1) - Body ground Always Below 1 Ω
      t14-53 (GND2) - Body ground Always Below 1 Ω
      t14-48 (ERTH) - Body ground Always Below 1 Ω

    5. Reconnect the t14 battery ECU assembly connector.

    6. Install the upper hybrid battery cover sub-assembly.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK FUSE (IGCT NO. 2)


    1. B006HKGC02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 IGCT NO. 2 Fuse

      Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IGCT NO. 2 fuse terminals - Body ground Always Below 1 Ω

    3. Install the IGCT NO. 2 fuse to the No. 1 engine room relay block and No. 1 junction block assembly.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - BATTERY ECU ASSEMBLY) Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (BATTERY ECU ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.


    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. Remove the upper hybrid battery cover sub-assembly.

      Click here

    3. B006J82N02

      Disconnect the t14 battery ECU assembly connector.

      Note

      Before disconnecting the connector, check that it is not loose or disconnected.

    4. Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      B006I8FC02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *a IGCT NO. 2 Fuse Terminal
      *b

      Front view of wire harness connector

      (to Battery ECU Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      t14-24 (IGCT) - 2 (IGCT NO. 2 fuse terminal) Always Below 1 Ω

    6. Install the IGCT NO. 2 fuse to the No. 1 engine room relay block and No. 1 junction block assembly.

    7. Reconnect the t14 battery ECU assembly connector.

    8. Install the upper hybrid battery cover sub-assembly.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Remove the IGCT SCENE relay from the No. 2 relay block.

      Note

      Check the relay for deformation and corrosion.

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

      B006IOCC04
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *a IGCT NO. 2 Fuse Terminal
      *b No. 2 Relay Block *c IGCT SCENE Relay Terminal
      Standard Resistance
      Tester Connection Condition Specified Condition
      5 (IGCT SCENE relay terminal) - 1 (IGCT NO. 2 fuse terminal) Always Below 1 Ω

    4. Install the IGCT SCENE relay to the No. 2 relay block.

    5. Install the IGCT NO. 2 fuse to the No. 1 engine room relay block and No. 1 junction block assembly.

      Result
      Proceed to
      OK
      NG

    OK

    CHECK ECU Power Source Circuit (HYBRID CONTROL SYSTEM) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY - BATTERY ECU ASSEMBLY)

    CAUTION:

    Be sure to wear insulated gloves and protective goggles.


    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. Remove the upper hybrid battery cover sub-assembly.

      Click here

    3. B006J82N02

      Disconnect the t14 battery ECU assembly connector.

      Note

      Before disconnecting the connector, check that it is not loose or disconnected.

    4. Remove the IGCT NO. 2 fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      B006I8FC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *a IGCT NO. 2 Fuse Terminal
      *b

      Front view of wire harness connector

      (to Battery ECU Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      t14-24 (IGCT) or 2 (IGCT NO. 2 fuse terminal) - Body ground and other terminals Always Below 1 Ω

    6. Install the IGCT NO. 2 fuse to the No. 1 engine room relay block and No. 1 junction block assembly.

    7. Reconnect the t14 battery ECU assembly connector.

    8. Install the upper hybrid battery cover sub-assembly.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUSE (IGCT NO. 2)

    NG

  7. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT NO. 2)