Toyota 4Runner Quiz
Vehicle Exterior

Front Fog Light Circuit

In this manual: Vehicle Exterior
General — 25Audio / Visual / Telematics — 283Brake — 187Drivetrain — 204Power Source / Network — 79Steering — 76Suspension — 130Vehicle Exterior — 391Vehicle Interior — 693
~1min read
DESCRIPTION

The main body ECU receives headlight dimmer switch information signals, and illuminates the front fog light.

WIRING DIAGRAM
CAUTION / NOTICE / HINT

NOTICE:

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

PROCEDURE

  1. PERFORM ACTIVE TEST USING TECHSTREAM (FRONT FOG LIGHT RELAY)

(a) Using the Techstream, perform the Active Test (See page ).


Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Front Fog Light Relay

Front fog light relay

ON/OFF

-

OK:

Front fog light relay operates (front fog lights come on).


OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)
NG

  1. CHECK MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

2D-9 - Body ground

Headlight dimmer switch in tail and front fog light switch on

11 to 14 V
Text in Illustration

*a

Component with harness connected

(Driver Side Junction Block Assembly)

OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (DRIVER SIDE JUNCTION BLOCK ASSEMBLY - FOG LIGHT ASSEMBLY)

NG

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

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