LIGHTING SYSTEM Power Source Circuit

DESCRIPTION

When the power switch is on (IG) or the operation conditions of the headlights are met, the main body ECU (multiplex network body ECU) supplies power to the No. 1 headlight ECU sub-assemblies via the No. 1 integration relay.

When the power switch is on (IG), the main body ECU (multiplex network body ECU) supplies power to the No. 1 headlight ECU sub-assemblies via the IG1-NO. 1 relay.

WIRING DIAGRAM

B004OYJE02

CAUTION / NOTICE / HINT

Note


  • Inspect the fuses for circuits related to this system before performing the following inspection 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 - POWER SOURCE AND BODY GROUND)


    1. Disconnect the A18 No. 1 headlight ECU sub-assembly LH connector.

    2. Disconnect the A19 No. 1 headlight ECU sub-assembly RH connector.

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

      Standard Voltage
      No. 1 Headlight ECU Sub-assembly LH
      Tester Connection Condition Specified Condition
      A18-13 (ECUB) - Body ground Power switch on (IG) 11 to 14 V
      A18-4 (IG) - Body ground Power switch on (IG) 11 to 14 V
      No. 1 Headlight ECU Sub-assembly RH
      Tester Connection Condition Specified Condition
      A19-13 (ECUB) - Body ground Power switch on (IG) 11 to 14 V
      A19-4 (IG) - Body ground Power switch on (IG) 11 to 14 V

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

      Standard Resistance
      No. 1 Headlight ECU Sub-assembly LH
      Tester Connection Condition Specified Condition
      A18-12 (GND) - Body ground Always Below 1 Ω
      No. 1 Headlight ECU Sub-assembly RH
      Tester Connection Condition Specified Condition
      A19-12 (GND) - Body ground Always Below 1 Ω
      Result
      Result Proceed to
      OK A
      NG (No. 1 Headlight ECU Sub-assembly LH) B
      NG (No. 1 Headlight ECU Sub-assembly RH) C

    A

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

    C

    INSPECT NO. 1 INTEGRATION RELAY (H-LP RH RELAY) Click here

    B

  2. INSPECT NO. 1 INTEGRATION RELAY (H-LP LH RELAY)


    1. Remove the No. 1 integration relay from the No. 1 engine room relay block and No. 1 junction block assembly.

      Click here

    2. Inspect the No. 1 integration relay.

      Click here

      OK
      No. 1 integration relay is normal.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (H-LP LH RELAY) - AUXILIARY BATTERY)


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1A-5 - Body ground Power switch off 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the 3F instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1B-2 - 3F-31 Always Below 1 Ω
      1B-2 or 3F-31 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    1. Remove the instrument panel junction block assembly.

      Click here

    2. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

      B004OH7C04
      *a

      Component without harness connected

      (Instrument Panel Junction Block Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      3F-31 - MB-15 (HRLY) Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

  6. INSPECT NO. 1 INTEGRATION RELAY (H-LP RH RELAY)


    1. Remove the No. 1 integration relay from the No. 1 engine room relay block and No. 1 junction block assembly.

      Click here

    2. Inspect the No. 1 integration relay.

      Click here

      OK
      No. 1 integration relay is normal.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 1 INTEGRATION RELAY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (H-LP RH RELAY) - AUXILIARY BATTERY)


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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1B-8 - Body ground Power switch off 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU))


    1. Disconnect the F17 main body ECU (multiplex network body ECU) connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1A-11 - F17-1 (DIM) Always Below 1 Ω
      1A-11 or F17-1 (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