LIGHTING SYSTEM Rear Fog Light Circuit

DTC Code DTC Name
Rear Fog Light Circuit

DESCRIPTION

When all of the following conditions are met, the rear fog lights come on.

  • The low beam headlights are turned on by automatic light control or manual light control.

  • The front fog lights are on.*

  • The rear fog light switch is on.

When any of the following conditions is met, the rear fog lights turn off.

  • The taillights are off.

  • The front fog light switch is off.*

  • The rear fog light switch is off.

Tip:

  • This circuit is only for vehicles with automatic light control or daytime running light control.

  • If the vehicle has automatic light control or daytime running light control, the exterior lights (headlights, taillights, front fog lights* and rear fog light) are controlled by the main body ECU.

  • If the vehicle does not have automatic light control or daytime running light control, the exterior lights (headlights, taillights, front fog lights* and rear fog light) are not controlled by the main body ECU. Perform troubleshooting according to the Problem Symptoms Table (Click here).

  • Before performing troubleshooting of rear fog light control, check that the low beam headlights and front fog lights* operate normally.

  • *: w/ Front Fog Light

WIRING DIAGRAM

E186278E01

CAUTION / NOTICE / HINT

Note:

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

PROCEDURE

  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (REAR FOG LIGHT RELAY)

    1. Using the intelligent tester, perform the Active Test (Click here).

      Table 1. Main Body

      Tester Display

      Test Part

      Control Range

      Diagnostic Note

      Rear Fog Light Relay

      Rear fog light relay

      ON/OFF

      -

      OK

      Rear fog light relay operates (rear fog light comes on).

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

  2. READ VALUE USING INTELLIGENT TESTER (REAR FOG LIGHT SWITCH)

    1. Using the intelligent tester, read the Data List (Click here).

      Table 2. Main Body

      Tester Display

      Measurement Item/Range

      Normal Condition

      Diagnostic Note

      Rear Fog Light SW

      Rear fog light switch signal / ON or OFF

      ON: Rear fog light switch on

      OFF: Rear fog light switch off

      -

      OK

      The display is as specified in the normal condition column.

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

  3. INSPECT REAR FOG LIGHT RELAY (RR FOG)

    E183428E01

    1. Remove the rear fog light relay from the No. 3 relay block.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      3 - 5

      Battery voltage not applied between terminals 1 and 2

      10 kΩ or higher

      3 - 5

      Battery voltage applied between terminals 1 and 2

      Below 1 Ω

    REPLACE REAR FOG LIGHT RELAY

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

    E142603E03

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      Rear fog light relay terminal 5 - Body ground

      Always

      11 to 14 V

      Rear fog light relay terminal 2 - Body ground

      Light control switch off → tail

      Below 1 V → 11 to 14 V
      Table 3. Text in Illustration

      *1

      No. 3 Relay Block

      *2

      Rear Fog Light Relay (RR FOG)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    U123645E02

    1. Disconnect the H80 main body ECU connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      Rear fog light relay terminal 1 - H80-11 (RFGO)

      Always

      Below 1 Ω

      H80-11 (RFGO) - Body ground

      Always

      10 kΩ or higher
      Table 4. Text in Illustration

      *1

      Front view of wire harness connector

      (to Main Body ECU)

      *2

      No. 3 Relay Block

      *3

      Rear Fog Light Relay (RR FOG)

      -

      -

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. CHECK MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

    U123641E02

    1. Reconnect the H80 main body ECU connector.

    2. Install the rear fog light relay to the No. 3 relay block.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      H80-11 (RFGO) - Body ground

      Light control switch in head and rear fog light switch off

      11 to 14 V

      Light control switch in head and rear fog light switch on

      Below 1 V
      Table 5. Text in Illustration

      *1

      Component with harness connected

      (Main Body ECU)

    REPAIR OR REPLACE HARNESS OR CONNECTOR (REAR FOG LIGHT RELAY [RR FOG] - REAR COMBINATION LIGHT ASSEMBLY [REAR FOG LIGHT])

    REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)