Last Modified: 11-29-2007 1.6 J
Service Category: Vehicle Exterior Section: Lighting (ext)
Model Year: 2008 Model: Sequoia Doc ID: RM000002WKU005X
Title: LIGHTING (EXT): LIGHTING SYSTEM: DESCRIPTION (2008 Sequoia)

Front Fog Light Circuit

DESCRIPTION

The main body ECU receives a front fog light switch information signal from the light control switch (front fog switch), and illuminates the front fog lights.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (FRONT FOG LIGHT)

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Active Test / Front Fog Light.

(e) Check that the front fog lights turn on/off.

Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Front Fog Light Relay

Front fog light

ON or OFF

-

OK:

Front fog lights turn on/off.

OK

2.

INSPECT FUSE (FOG)

(a) Remove the FOG fuse from the engine room junction block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

FOG fuse

Always

Below 1 Ω

(c) Reinstall the FOG fuse.

OK

3.

INSPECT FOG LIGHT BULB

(a) Temporarily replace the front fog light bulb with a new or normally functioning one LIGHTING (EXT): FOG LIGHT ASSEMBLY: DISASSEMBLY (2008 Sequoia)+ .

(b) Check that the front fog light turn on.

OK:

front fog light turn on.

OK

4.

CHECK HARNESS AND CONNECTOR (FRONT FOG LIGHT BULB - BATTERY)


(a) for LH:

(1) Disconnect the A36 front fog light LH connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A36-2 - Body ground

Light control switch TAIL, front fog light switch ON

11 to 14 V

Light control switch TAIL, front fog light switch OFF

Below 1 V

(3) Reconnect the front fog light LH connector.

(b) for RH:

(1) Disconnect the A37 front fog light RH connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

A37-2 - Body ground

Light control switch TAIL, front fog light switch ON

11 to 14 V

Light control switch TAIL, front fog light switch OFF

Below 1 V

(3) Reconnect the front fog light RH connector.

OK

5.

INSPECT FOG LIGHT RELAY (FOG)


(a) Remove the fog light relay from the engine room relay block.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

3 - 5

When battery voltage is not applied to terminals 1 and 2

10 kΩ or higher

When battery voltage is applied to terminals 1 and 2

Below 1 Ω

(c) Reinstall the fog light relay.

OK

6.

CHECK HARNESS AND CONNECTOR (FOG LIGHT RELAY - BATTERY, TAIL RELAY)


(a) Remove the fog light relay from the engine room relay block.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

Fog light relay terminal 1 - Body ground

Light control switch TAIL

11 to 14 V

Fog light relay terminal 3 - Body ground

Always

11 to 14 V

(c) Reinstall the fog light relay.

OK

7.

CHECK HARNESS AND CONNECTOR (FR FOG RELAY - FRONT FOG LIGHT BULB)

(a) Remove the fog light relay from the engine room relay block.

(b) for LH:

(1) Disconnect the A36 front fog light LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Fog light relay terminal 5 - A36-2

Always

Below 1 Ω

Fog light relay terminal 5 - Body ground

Always

10 kΩ or higher

(3) Reconnect the front fog light LH connector.

(c) for RH:

(1) Disconnect the A37 front fog light RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Fog light relay terminal 5 - A37-2

Always

Below 1 Ω

Fog light relay terminal 5 - Body ground

Always

10 kΩ or higher

(3) Reconnect the front fog light RH connector.

(d) Reinstall the fog light relay.

OK

8.

CHECK HARNESS AND CONNECTOR (FOG LIGHT RELAY - MAIN BODY ECU)


(a) Disconnect the H4 main body ECU connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

H4-4 - Body ground

Light control switch TAIL

11 to 14 V

(c) Reconnect the main body ECU connector.

OK