Last Modified: 11-29-2007 1.6 J
Service Category: Vehicle Exterior Section: Lighting (ext)
Model Year: 2008 Model: Sequoia Doc ID: RM000002WKW005X
Title: LIGHTING (EXT): LIGHTING SYSTEM: DESCRIPTION (2008 Sequoia)

Taillight Circuit

DESCRIPTION

The main body ECU receives a light control switch information signal from the headlight dimmer switch, and illuminates the taillights.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1.

PERFORM ACTIVE TEST USING TECHSTREAM (TAILLIGHT)

(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 / Tail Light

(e) Check that the taillights turn on/off.

Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Taillight Relay

Taillight

ON or OFF

-

OK:

Taillights turn on/off.

Result

Result

Proceed to

OK

A

NG (All taillights do not turn on)

B

NG (Front parking lights and side marker light do not turn on)

C

NG (Taillight and license plate light do not turn on)

D
A

2.

INSPECT FUSE (TAIL)

(a) Remove the TAIL fuse from the main body ECU.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

TAIL fuse

Always

Below 1 Ω

(c) Reinstall the TAIL fuse.

OK

3.

CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - BATTERY)


(a) Disconnect the DA main body ECU connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

DA-1 - Body ground

Always

11 to 14 V

(c) Reconnect the main body ECU connector.

OK

4.

CHECK VEHICLE CONDITION

(a) Check vehicle condition.

Result

Result

Proceed to

Front parking light and side marker light do not turn on

A

Front parking light does not turn on

B

Side marker light does not turn on

C
A

5.

INSPECT MAIN BODY ECU

(a) Remove the main body ECU with its connector still connected.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

DB-8 - Body Ground

Light control switch

OFF → TAIL

Below 1 V → 11 to 14 V

(c) Reinstall the main body ECU.

OK

6.

INSPECT FRONT PARKING LIGHT BULB

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

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

OK:

Front parking light turn on.

OK

7.

CHECK HARNESS AND CONNECTOR (FRONT PARKING LIGHT - BODY GROUND)


(a) for LH

(1) Disconnect the A15 front parking light connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A15-2 (E) - Body Ground

Always

Below 1 Ω

(3) Reconnect the front parking light connector.

(b) for RH

(1) Disconnect the A16 front parking light connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A16-2 (E) - Body Ground

Always

Below 1 Ω

(3) Reconnect the front parking light connector.

OK

8.

INSPECT SIDE MARKER LIGHT BULB

(a) Temporarily replace the side marker light bulb with a new or normally functioning one LIGHTING (EXT): HEADLIGHT ASSEMBLY: DISASSEMBLY (2008 Sequoia)+ .

(b) Check that the side marker light turn on.

OK:

Side marker light turn on.

OK

9.

CHECK HARNESS AND CONNECTOR (SIDE MARKER LIGHT - BODY GROUND)


(a) for LH

(1) Disconnect the A39 side marker light connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A39-1 - Body Ground

Always

Below 1 Ω

(3) Reconnect the side marker light connector.

(b) for RH

(1) Disconnect the A38 front parking light connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

A38-1 - Body Ground

Always

Below 1 Ω

(3) Reconnect the front turn signal light connector.

OK

10.

CHECK VEHICLE CONDITION

(a) Check vehicle condition.

Result

Result

Proceed to

Taillight and license plate light does not turn on

A

Taillight (for Rear combination light) does not turn on

B

Taillight (for Rear light) does not turn on

C

License plate light does not turn on

D
A

11.

INSPECT MAIN BODY ECU

(a) Remove the main body ECU with its connector still connected.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

DC-22 - Body Ground

Light control switch

OFF → TAIL

Below 1 V → 11 to 14 V

(c) Reinstall the main body ECU.

OK

12.

INSPECT REAR COMBINATION LIGHT BULB (TAILLIGHT BULB)

(a) Temporarily replace the rear combination light (taillight) bulb with a new or normally functioning one LIGHTING (EXT): REAR COMBINATION LIGHT ASSEMBLY: DISASSEMBLY (2008 Sequoia)+ .

(b) Check that the rear combination light (taillight) turn on.

OK:

Rear combination light (taillight) turn on.

OK

13.

CHECK HARNESS AND CONNECTOR (REAR COMBINATION LIGHT (TAILLIGHT) - BODY GROUND)


(a) for LH:

(1) Disconnect the O21 rear combination light LH connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

O21-1 (E) - Body ground

Always

Below 1 Ω

(3) Reconnect the rear combination light LH connector.

(b) for RH:

(1) Disconnect the O20 rear combination light RH connector.

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

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

O20-1 (E) - Body ground

Always

Below 1 Ω

(3) Reconnect the rear combination light RH connector.

OK

14.

INSPECT REAR LIGHT (TAILLIGHT BULB)

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

(b) Check that the rear light (taillight) turn on.

OK:

Rear light (taillight) turn on.

OK

15.

CHECK HARNESS AND CONNECTOR (REAR LIGHT (TAILLIGHT) - BODY GROUND)


(a) for LH:

(1) Disconnect the V8 rear light LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

V8-3 (E) - Body ground

Always

Below 1 Ω

(3) Reconnect the rear light LH connector.

(b) for RH:

(1) Disconnect the V7 rear light RH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

V7-3 (E) - Body ground

Always

Below 1 Ω

(3) Reconnect the rear light RH connector.

OK

16.

INSPECT LICENSE PLATE LIGHT BULB

(a) Temporarily replace the license plate light bulb with a new or normally functioning one LIGHTING (EXT): LICENSE PLATE LIGHT ASSEMBLY: REMOVAL (2008 Sequoia)+ .

(b) Check that the license plate light turns on.

OK:

License plate light turns on.

OK

17.

CHECK HARNESS AND CONNECTOR (LICENSE PLATE LIGHT - BODY GROUND)


(a) Disconnect the V9 license plate light LH connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

V9-1 (E) - Body ground

Always

Below 1 Ω

(c) Reconnect the license plate light connector.

(1) Reconnect the license plate light connector.

OK