LIGHTING SYSTEM Rear Fog Light Circuit

DESCRIPTION

Illumination of the rear fog lights is controlled by the main body ECU (multiplex network body ECU).

WIRING DIAGRAM

B006L5VE03

CAUTION / NOTICE / HINT

Note


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

  • Before performing troubleshooting, check that the taillight relay circuit operates properly.

  • 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. PERFORM ACTIVE TEST USING GTS (REAR FOG LIGHT RELAY)


    1. Using the GTS, perform the Active Test.

      Click here


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Rear Fog Light Relay Rear fog light relay ON or OFF The headlight dimmer switch (light control switch) is in the tail position.

      Body Electrical > Main Body > Active Test
      Tester Display
      Rear Fog Light Relay

      Tech Tips

      Check the operation with the taillights illuminated.

      Result
      Result Proceed to
      The Active Test is performed normally A
      The Active Test is not performed normally B

    A

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

    B

  2. INSPECT JUNCTION BLOCK ASSEMBLY LH (FOG RELAY)


    1. Remove the junction block assembly LH.

      Click here

      B006KHNN01

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

      Click here

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      4K-1 - 4H-14 Battery voltage applied to terminals 4K-1 and A-14 (TRLY), and 4K-1 and A-27 (RFGO) 11 to 14 V
      4K-1 - 4H-14 Battery voltage not applied to terminals 4K-1 and A-14 (TRLY), and 4K-1 and A-27 (RFGO) Below 1 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE JUNCTION BLOCK ASSEMBLY LH (FOG RR) Click here

    OK

  3. CHECK HARNESS AND CONNECTOR (REAR LIGHT LENS AND BODY RH - JUNCTION BLOCK ASSEMBLY LH)


    1. Disconnect the U4 rear light lens and body RH connector.

    2. Disconnect the U12 rear light lens and body LH connector.

    3. Disconnect the 4H junction block assembly LH connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      U4-1 (B) - 4H-14 Always Below 1 Ω
      U4-1 (B) or 4H-14 - 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