LIGHTING SYSTEM Power Source Circuit

DESCRIPTION

The main body ECU (multiplex network body ECU) receives IG signals and supplies power to the headlight ECU sub-assembly via the headlight light dimmer relay.

WIRING DIAGRAM

B0019UVE02

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • If the main body ECU (multiplex network body ECU) is replaced, refer to Service Bulletin.

  • w/ Door Control Battery:

    As the door control battery is installed between the vehicle battery and main body ECU (multiplex network body ECU), first perform the inspections in On-Vehicle Inspection to confirm that there are no malfunctions in the power source circuit for the main body ECU (multiplex network body ECU) before performing this troubleshooting procedure Click here.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (HEADLIGHT ECU SUB-ASSEMBLY - POWER SOURCE AND BODY GROUND)


    1. Disconnect the A64*1and A65*2 headlight ECU sub-assembly connectors.


      • *1: for LH Side

      • *2: for RH Side

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

      Standard Voltage
      for LH Side
      Tester Connection Switch Condition Specified Condition
      A64-13 (ECUB) - Body ground Engine switch on (IG) or light control switch tail or head position 11 to 14 V
      A64-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      for RH Side
      Tester Connection Switch Condition Specified Condition
      A65-13 (ECUB) - Body ground Engine switch on (IG) or light control switch tail or head position 11 to 14 V
      A65-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V

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

      Standard Resistance
      for LH Side
      Tester Connection Condition Specified Condition
      A64-12 (GND) - Body ground Always Below 1 Ω
      for RH Side
      Tester Connection Condition Specified Condition
      A65-12 (GND) - Body ground Always Below 1 Ω
      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

    CHECK H-LP HI OR H-LP RH RELAY Click here

    B

  2. INSPECT H-LP LO OR H-LP LH RELAY


    1. Remove the H-LP LO or H-LP LH relay from the engine room relay block.

    2. Inspect the H-LP LO or H-LP LH relay Click here.


    NG

    REPLACE H-LP LO OR H-LP LH RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (BATTERY - H-LP LO OR H-LP LH RELAY)


    1. B0018RAE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to H-LP LO or H-LP LH relay relay)

      Remove the H-LP LO or H-LP LH relay relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Relay terminal 1 - Body ground Always 11 to 14 V
      Relay terminal 3- Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (H-LP LO OR H-LP LH RELAY - HEADLIGHT ECU SUB-ASSEMBLY LH)


    1. Remove the H-LP LO or H-LP LH relay from the engine room relay block.

    2. Disconnect the A64 headlight ECU sub-assembly LH connectors.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 5- A64-13 (ECUB) Always Below 1 Ω
      Relay terminal 5 or A64-13 (ECUB) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (H-LP LO OR H-LP LH RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))


    1. Remove the H-LP LO or H-LP LH relay from the engine room relay block.

    2. Remove the cowl side junction block LH.


    3. Remove the main body ECU (multiplex network body ECU) from the cowl side junction block LH.


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 2 - A-15 (HRLY) Always Below 1 Ω
      Relay terminal 2 or A-15 (HRLY) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

  6. CHECK HARNESS AND CONNECTOR (H-LP LO OR H-LP LH RELAY - COWL SIDE JUNCTION BLOCK LH)


    1. Remove the H-LP LO or H-LP LH relay from the engine room relay block.

    2. Disconnect the 2H cowl side junction block LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 2 - 2H-30 Always Below 1 Ω
      Relay terminal 2 or 2H-30 - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    B

    REPLACE COWL SIDE JUNCTION BLOCK LH Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK H-LP HI OR H-LP RH RELAY


    1. Remove the H-LP HI or H-LP RH relay from the engine room relay block.

    2. Inspect the H-LP HI or H-LP RH relay Click here.


    NG

    REPLACE H-LP HI OR H-LP RH RELAY

    OK

  8. CHECK HARNESS AND CONNECTOR (H-LP HI OR H-LP RH RELAY - BATTERY)


    1. B0018RAE01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to H-LP HI or H-LP RH relay)

      Remove the H-LP HI or H-LP RH relay from the engine room relay block.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Relay terminal 1 - Body ground Always 11 to 14 V
      Relay terminal 3- Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (H-LP HI OR H-LP RH RELAY - HEADLIGHT ECU SUB-ASSEMBLY RH AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))


    1. Remove the H-LP HI or H-LP RH relay from the engine room relay block.

    2. Disconnect the A65 headlight ECU sub-assembly RH connector.

    3. Disconnect the E118 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
      Relay terminal 5- A65-13 (ECUB) Always Below 1 Ω
      Relay terminal 2 - E118-1 (DIM) Always Below 1 Ω
      Relay terminal 5 or A65-13 (ECUB) - Body ground Always 10 kΩ or higher
      Relay terminal 2 or E118-1 (DIM) - Body ground Always 10 kΩ or higher
      Result
      Result Proceed to
      OK (for LHD) A
      OK (for RHD) B
      NG C

    A

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

    B

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

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR