Toyota 4Runner: Taillight Relay Circuit

Toyota 4Runner Service Manual / Vehicle Exterior / Lighting (ext) / Lighting System / Taillight Relay Circuit

DESCRIPTION

The main body ECU receives headlight dimmer switch information signals, and illuminates the clearance lights, taillights and license plate lights.

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 (TAILLIGHT RELAY)

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

Main Body

Tester Display	Test Part	Control Range	Diagnostic Note
Taillight Relay	Taillight relay	ON/OFF	-

OK:

Taillight relay operates (taillights illuminate).

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

2.	CHECK HARNESS AND CONNECTOR (BATTERY - MAIN BODY ECU)

(a) Remove the main body ECU (See page ).

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
A-14 (TRLY) - Body ground	Always	11 to 14 V

Text in Illustration

*a	Front view of wire harness connector (to Main Body ECU)

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

REPAIR OR REPLACE HARNESS OR CONNECTOR

Front Fog Light Circuit

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 b ...

Rear Combination Light Assembly

Components COMPONENTS ILLUSTRATION Removal REMOVAL CAUTION / NOTICE / HINT HINT: Use the same procedure for both the RH and LH sides. The procedure listed below is for the LH ...

Other materials about Toyota 4Runner:

Back door
The back door can be locked/unlocked and opened by the following procedures: Locking and unlocking the back door Entry function (vehicles with a smart key system) Wireless remote control Door lock switch Keys (vehicles without a smart key system) 1. ...

Precaution
PRECAUTION 1. IGNITION SWITCH EXPRESSION HINT: The type of ignition switch used on this model differs according to the specifications of the vehicle. The expressions listed in the table below are used in this section. Expression Ign ...