LIGHTING SYSTEM Power Source Circuit

DESCRIPTION

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

WIRING DIAGRAM

B006MWEE01

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 the Service Bulletin.

  • 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.

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY - BATTERY AND BODY GROUND)


    1. B006L4FC16
      *A Headlight light control ECU sub-assembly LH (main)
      *B Headlight light control ECU sub-assembly RH (sub)
      *a

      Front view of wire harness connector

      (to Headlight Light Control ECU Sub-assembly)

      Disconnect the headlight light control ECU sub-assembly LH (main) or headlight light control ECU sub-assembly RH (sub) connector.

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

      Standard Voltage
      Headlight light control ECU sub-assembly LH (main)
      Tester Connection Switch Condition Specified Condition
      A28-13 (ECUB) - Body ground Engine switch on (IG) 11 to 14 V
      Headlight light control ECU sub-assembly RH (sub)
      Tester Connection Switch Condition Specified Condition
      A29-13 (ECUB) - 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
      Headlight light control ECU sub-assembly LH (main)
      Tester Connection Condition Specified Condition
      A28-12 (GND) - Body ground Always Below 1 Ω
      Headlight light control ECU sub-assembly RH (sub)
      Tester Connection Condition Specified Condition
      A29-12 (GND) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK A
      NG (Headlight Light Control ECU Sub-assembly LH [main]) B
      NG (Headlight Light Control ECU Sub-assembly RH [sub]) C

    A

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

    C

    CHECK HEADLIGHT RELAY (H-LP RH) Click here

    B

  2. INSPECT HEADLIGHT RELAY (H-LP LH)


    1. Remove the headlight relay (H-LP LH) from the No. 1 engine room relay block.

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

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT RELAY (H-LP LH)

    OK

  3. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LH] - BATTERY)


    1. B006NKOC03
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP LH])

      Remove the headlight relay (H-LP LH) from the No. 1 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 1 - Body ground Always 11 to 14 V
      Relay terminal 5 - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LH] - HEADLIGHT LIGHT CONTROL ECU SUB-ASSEMBLY LH [MAIN])


    1. Remove the headlight relay (H-LP LH) from the No. 1 engine room relay block.

    2. Disconnect the A28 headlight light control ECU sub-assembly LH (main) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 3 - A28-13 (ECUB) Always Below 1 Ω
      Relay terminal 3 or A28-13 (ECUB) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LH] - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Remove the headlight relay (H-LP LH) from the No. 1 engine room relay block.

    2. Remove the junction block assembly LH.

      Click here

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

      Click here

    4. Disconnect the 4F junction block assembly LH connector.

    5. 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
      Proceed to
      OK
      NG

    OK

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

    NG

  6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LH] - JUNCTION BLOCK ASSEMBLY LH)


    1. Remove the headlight relay (H-LP LH) from the No. 1 engine room relay block.

    2. Disconnect the 4F junction block assembly 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 - 4F-30 Always Below 1 Ω
      Relay terminal 2 or 4F-30 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE JUNCTION BLOCK ASSEMBLY LH Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  7. CHECK HEADLIGHT RELAY (H-LP RH)


    1. Remove the headlight relay (H-LP RH) from the No. 2 engine room relay block.

    2. Inspect the headlight light relay (H-LP RH).

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEADLIGHT RELAY (H-LP RH)

    OK

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


    1. B006NKOC03
      *a

      Front view of wire harness connector

      (to Headlight Relay [H-LP RH])

      Remove the headlight relay (H-LP RH) from the No. 2 engine room relay block.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      Relay terminal 2 - Body ground Always 11 to 14 V
      Relay terminal 3 - 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 RH RELAY] - HEADLIGHT LIGHT CONTROL ECU ASSEMBLY RH AND MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Remove the headlight relay (H-LP RH) from the No. 2 engine room relay block.

    2. Disconnect the A29 headlight light control ECU sub-assembly RH (sub) connector.

    3. Disconnect the G63 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 - A29-13 (ECUB) Always Below 1 Ω
      Relay terminal 1 - G63-1 (DIM) Always Below 1 Ω
      Relay terminal 5 or A29-13 (ECUB) - Body ground Always 10 kΩ or higher
      Relay terminal 1 or G63-1 (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