Toyota 4Runner manuals

Toyota 4Runner: Headlight Relay Circuit

DESCRIPTION

The main body ECU receives headlight dimmer switch information signals, and illuminates the low beam headlight.

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 (HEADLIGHT RELAY)

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


Main Body

Tester Display

Test Part

Control Range

Diagnostic Note

Headlight Relay

Low beam headlight relay

ON/OFF

-

OK:

Headlight relay operates (low beam headlights illuminate).


OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE


NG

2.

INSPECT HEADLIGHT RELAY (H-LP LO)

(a) Remove the headlight relay from the engine room relay block, junction block.


(b) 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

Battery voltage applied between terminals 1 and 2

Below 1 Ω


NG

REPLACE HEADLIGHT RELAY


OK

3.

CHECK HARNESS AND CONNECTOR (BATTERY - HEADLIGHT RELAY [H-LP LO])

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

Headlight relay terminal 1 - Body ground

Always

11 to 14 V

Headlight relay terminal 5 - Body ground

Text in Illustration

*a

Front view of wire harness connector

(to Headlight Relay)



NG

REPAIR OR REPLACE HARNESS OR CONNECTOR


OK

4.

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - MAIN BODY ECU)

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


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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Headlight relay terminal 2 - A-15 (HRLY)

Always

Below 1 Ω

A-15 (HRLY) - Body ground

Always

10 kΩ or higher


OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

Headlight Dimmer Switch Circuit
DESCRIPTION The main body ECU receives the following signals: Headlight dimmer switch tail, head, AUTO*, high or high flash signal Front fog light switch signal *: w/ Aut ...

Headlight (HI-BEAM) Circuit
DESCRIPTION The main body ECU (multiplex network body ECU) receives headlight dimmer switch information signals, and illuminates the high beam headlight. WIRING DIAGRAM CAUTION / NOTICE / HINT ...

Other materials about Toyota 4Runner:

System Description
SYSTEM DESCRIPTION 1. KEY REMINDER WARNING SYSTEM DESCRIPTION (a) When the driver side door is opened while the ignition switch is ACC or off and the key is in the ignition key cylinder, this system causes a buzzer to sound in order to warn the driver th ...

Problem Symptoms Table
PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of probability in the "Suspected Area" column of ...

© 2016-2020 | www.to4runner.net

0.0033