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

B002HW7E04

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 Service Bulletin.

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 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 (for LHD) B
      The Active Test is not performed normally (for RHD) C

    A

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

    C

    INSPECT REAR FOG LIGHT RELAY (FOG RR) Click here

    B

  2. INSPECT REAR FOG LIGHT RELAY (FOG RR)


    1. Remove the rear fog light relay from the junction block.

    2. Inspect the rear fog light relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE REAR FOG LIGHT RELAY (FOG RR)

    OK

  3. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - BATTERY)


    1. B002KI1C10
      *a

      Front view of wire harness connector

      (to Rear Fog Light Relay [FOG RR])

      Remove the rear fog light relay from the junction block.

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

      Standard Voltage
      Tester Connection Swich Condition Specified Condition
      Relay terminal 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 (TAIL RELAY - REAR FOG LIGHT RELAY [FOG RR])


    1. B002KI1C10
      *a

      Front view of wire harness connector

      (to Rear Fog Light Relay [FOG RR])

      Remove the rear fog light relay from the junction 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

      • Headlight dimmer switch off →TAIL orHEAD (When vehicle has the dimmer switch off position)

      • Headlight dimmer switch in AUTO with low beams off → low beams on

      		 Below 1 V → 11 to 14 V
      If the low beams are illuminated, shine a light on the automatic light control sensor to change the system to daytime mode.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - REAR LIGHT ASSEMBLY LH AND BODY GROUND)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the Y11 rear light assembly LH.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 3 - Y11-1 (B) Always Below 1 Ω
      Y11-4 (E) - Body ground Always Below 1 Ω
      Relay terminal 3 or Y11-1 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Remove the rear fog light relay from the junction block.

    2. Remove the instrument panel junction block assembly.

      Click here

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

      Click here

    4. Reconnect the 4D instrument panel junction block assembly 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-27 (RFGO) Always Below 1 Ω
      Relay terminal 2 or A-27 (RFGO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  7. INSPECT REAR LIGHT ASSEMBLY LH


    1. Remove the rear light assembly LH.

      Click here

    2. Inspect the rear light assembly LH.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE REAR LIGHT ASSEMBLY LH Click here

  8. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the 4C instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 1 - 4C-22 Always Below 1 Ω
      Relay terminal 1 or 4C-22 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  9. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the 4D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 2 - 4D-53 Always Below 1 Ω
      Relay terminal 2 or 4D-53 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. INSPECT REAR FOG LIGHT RELAY (FOG RR)


    1. Remove the rear fog light relay from the junction block.

    2. Inspect the rear fog light relay.

      Click here

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE REAR FOG LIGHT RELAY (FOG RR)

    OK

  11. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - BATTERY)


    1. B002KI1C10
      *a

      Front view of wire harness connector

      (to Rear Fog Light Relay [FOG RR])

      Remove the rear fog light relay from the junction block.

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

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  12. CHECK HARNESS AND CONNECTOR (TAILLIGHT RELAY [TAIL RELAY] - REAR FOG LIGHT RELAY [FOG RR])


    1. B002KI1C10
      *a

      Front view of wire harness connector

      (to Rear Fog Light Relay [FOG RR])

      Remove the rear fog light relay from the junction 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

      • Headlight dimmer switch off →TAIL orHEAD (When vehicle has the dimmer switch off position)

      • Headlight dimmer switch in AUTO with low beams off → low beams on

      		 Below 1 V → 11 to 14 V
      If the low beams are illuminated, shine a light on the automatic light control sensor to change the system to daytime mode.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  13. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - REAR LIGHT ASSEMBLY RH AND BODY GROUND)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the Y10 rear light assembly RH.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 3 - Y10-1 (B) Always Below 1 Ω
      Y10-4 (E) - Body ground Always Below 1 Ω
      Relay terminal 3 or Y10-1 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  14. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Remove the rear fog light relay from the junction block.

    2. Remove the instrument panel junction block assembly.

      Click here

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

      Click here

    4. Reconnect the 4D instrument panel junction block assembly 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-27 (RFGO) Always Below 1 Ω
      Relay terminal 2 or A-27 (RFGO) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY) Click here

    OK

  15. INSPECT REAR LIGHT ASSEMBLY RH


    1. Remove the rear light assembly RH.

      Click here

    2. Inspect the rear light assembly RH.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

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

    NG

    REPLACE REAR LIGHT ASSEMBLY RH Click here

  16. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the 4C instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 1 - 4C-22 Always Below 1 Ω
      Relay terminal 1 or 4C-22 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  17. CHECK HARNESS AND CONNECTOR (REAR FOG LIGHT RELAY [FOG RR] - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)


    1. Remove the rear fog light relay from the junction block.

    2. Disconnect the 4D instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      Relay terminal 2 - 4D-53 Always Below 1 Ω
      Relay terminal 2 or 4D-53 - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR