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


  1. w/ Door Ajar Warning Buzzer Function:

    B006L5VE07

  2. w/o Door Ajar Warning Buzzer Function:

    B006PJFE01

CAUTION / NOTICE / HINT

Note


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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    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 (w/ Door Ajar Warning Buzzer Function) B
      The Active Test is not performed normally (w/o Door Ajar Warning Buzzer Function) C

    A

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

    C

    INSPECT REAR FOG LIGHT SET Click here

    B

  2. INSPECT JUNCTION BLOCK ASSEMBLY LH


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4K-1 - 4H-14 Always 10 kΩ or higher

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

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

    NG

    REPLACE JUNCTION BLOCK ASSEMBLY LH Click here

    OK

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


    1. Disconnect the U20 rear light assembly RH connector.

    2. Disconnect the U23 rear light assembly 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
      U20-2 (B) - 4H-14 Always Below 1 Ω
      U20-2 (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

  4. INSPECT REAR FOG LIGHT SET


    1. Remove the rear fog light set.

      Click here

    2. Inspect the rear fog light set.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE REAR FOG LIGHT SET Click here

    OK

  5. INSPECT JUNCTION BLOCK ASSEMBLY LH


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

      Standard Resistance
      Tester Connection Condition Specified Condition
      4K-1 - 4H-14 Always 10 kΩ or higher

    4. 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
      Battery voltage not applied to terminals 4K-1 and A-14 (TRLY), and 4K-1 and A-27 (RFGO) Below 1 V
      Battery voltage applied to terminals 4K-1 and A-27 (RFGO)
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE JUNCTION BLOCK ASSEMBLY LH Click here

    OK

  6. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT SET - JUNCTION BLOCK ASSEMBLY LH)


    1. Disconnect the K39 rear fog light set connector.

    2. Disconnect the 4H 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
      K39-2 (S) - 4H-14 Always Below 1 Ω
      K39-1 (E) - Body ground Always Below 1 Ω
      K39-2 (S) 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