LIGHTING SYSTEM(for LED Headlight) Power Source Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives IG signals and supplies power to the No. 1 headlight ECU sub-assembly via the headlight light dimmer relay.

WIRING DIAGRAM

B001CZZE02

CAUTION / NOTICE / HINT

Note


  • Inspect the fuse for circuits related to this system before performing the follow procedure.

  • Before replacing the main body ECU (multiplex network body ECU), refer to Service Bulletin.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY - BATTERY AND BODY GROUND)


    1. Disconnect the A102 No. 1 headlight ECU sub-assembly LH connector.

    2. Disconnect the A103 No. 1 headlight ECU sub-assembly RH connector.

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

      Standard Voltage
      for RH Side
      Tester Connection Switch Condition Specified Condition
      A103-4 (IG) - Body ground Ignition switch ON 11 to 14 V

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

      Standard Resistance
      for LH Side
      Tester Connection Condition Specified Condition
      A102-12 (GND) - Body ground Always Below 1 Ω
      for RH Side
      Tester Connection Condition Specified Condition
      A103-12 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (NO. 1 HEADLIGHT ECU SUB-ASSEMBLY - BATTERY)


    1. Disconnect the A102 No. 1 headlight ECU sub-assembly LH connector.

    2. Disconnect the A103 No. 1 headlight ECU sub-assembly RH connector.

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

      Standard Voltage
      for LH Side
      Tester Connection Condition Specified Condition
      A102-13 (ECUB) - Body ground Ignition switch ON, light control switch in Tail or Head position 11 to 14 V
      Ignition switch ON, light control switch in off position Below 1 V
      for RH Side
      Tester Connection Condition Specified Condition
      A103-13 (ECUB) - Body ground Ignition switch ON, light control switch in Tail or Head position 11 to 14 V
      Ignition switch ON, light control switch in off position Below 1 V
      Result
      Result Proceed to
      OK A
      NG (for LH Side) B
      NG (for RH Side) C

    A

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    C

    INSPECT HEADLIGHT RELAY (H-LP HI) Click here

    B

  3. INSPECT HEADLIGHT RELAY (H-LP LO)


    1. Remove the headlight relay (H-LP LO) from engine room relay block.

    2. Inspect the headlight relay (H-LP LO) relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT RELAY (H-LP LO)

    OK

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - BATTERY)


    1. B001HRSC03
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP LO])

      Remove the headlight relay (H-LP LO) from engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP LO) terminal 1 - Body ground Always 11 to 14 V
      Headlight relay (H-LP LO) terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH AND DRIVER SIDE JUNCTION BLOCK ASSEMBLY)


    1. Remove the headlight relay (H-LP LO) from engine room relay block.

    2. Disconnect the A102 No. 1 headlight ECU sub-assembly LH connector.

    3. Disconnect the 2M driver side junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP LO) terminal 3 - A102-13 (ECUB) Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 2 - 2M-17 Always Below 1 Ω
      Headlight relay (H-LP LO) terminal 3 or A102-13 (ECUB) - Body ground Always 10 kΩ or higher
      Headlight relay (H-LP LO) terminal 2 or 2M-17 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK DRIVER SIDE JUNCTION BLOCK ASSEMBLY


    1. B001HUUC01
      *a

      Component without harness connected

      (Driver Side Junction Block Assembly)

      Remove the driver side junction block assembly.

      Click here

    2. Remove the main body ECU (multiplex network body ECU) from the driver side junction block assembly.

      Click here

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      2M-17 - A-15 (HRLY) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY Click here

  7. INSPECT HEADLIGHT RELAY (H-LP HI)


    1. Remove the headlight relay (H-LP HI) from engine room relay block.

    2. Inspect the headlight relay (H-LP HI) relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT RELAY (H-LP HI)

    OK

  8. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP HI] - BATTERY)


    1. B001HRSC03
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP HI])

      Remove the headlight relay (H-LP HI) from engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP HI) terminal 1 - Body ground Always 11 to 14 V
      Headlight relay (H-LP HI) terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - NO. 1 HEADLIGHT ECU SUB-ASSEMBLY RH AND MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Remove the headlight relay (H-LP HI) from engine room relay block.

    2. Disconnect the A103 No. 1 headlight ECU sub-assembly RH connector.

    3. Disconnect the G218 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Headlight relay (H-LP HI) terminal 3 - A103-13 (ECUB) Always Below 1 Ω
      Headlight relay (H-LP HI) terminal 2 - G218-1 (DIM) Always Below 1 Ω
      Headlight relay (H-LP HI) terminal 3 or A103-13 (ECUB) - Body ground Always 10 kΩ or higher
      Headlight relay (H-LP HI) terminal 2 or G218-1 (DIM) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR