Lighting System Headlight Relay Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEADLIGHT RELAY)

INSPECT HEADLIGHT RELAY (H-LP LO)

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

CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY

LIGHTING SYSTEM - Headlight Relay Circuit


DESCRIPTION

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

WIRING DIAGRAM


Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System.Lighting System Headlight Relay Circuit


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses and bulbs for circuits related to this system before performing the following inspection procedure.
1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER (HEADLIGHT RELAY)

  1. Using the intelligent tester, perform the Active Test (LandCruiser RM000000PKV0J6X.html).

    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).


NG
Go to step 2
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (LandCruiser RM000003WBO05FX.html)

2.INSPECT HEADLIGHT RELAY (H-LP LO)


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System.Lighting System Headlight Relay Circuit

  1. Remove the headlight relay from the engine room relay block.

  1. 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
    3 - 5
    		Battery voltage applied between terminals 1 and 2
    		Below 1 Ω


NG
REPLACE HEADLIGHT RELAY (H-LP LO)
OK


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


    Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System.Lighting System Headlight Relay Circuit

  1. 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 [H-LP LO])


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY [H-LP LO] - DRIVER SIDE JUNCTION BLOCK ASSEMBLY)

  1. Remove the headlight relay from the engine room relay block.

  1. Disconnect the 2F driver side junction block assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Headlight relay terminal 2 - 2F-40
    		Always
    		Below 1 Ω
    2F-40 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT DRIVER SIDE JUNCTION BLOCK ASSEMBLY
Land Cruiser, Land Cruiser Prado. Grj150 Trj150,155 Kdj150,155 Lj150, Gdj150,155.Lighting (Ext).Lighting System.Lighting System Headlight Relay Circuit

  1. Remove the driver side junction block assembly (LandCruiser RM000003WBO05FX.html).

  1. Remove the main body ECU from the driver side junction block assembly (LandCruiser RM000003WBO05FX.html).

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A-15 (HRLY) - 2F-40
    		Always
    		Below 1 Ω


NG
REPLACE DRIVER SIDE JUNCTION BLOCK ASSEMBLY (LandCruiser RM000003WBO05FX.html)
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (LandCruiser RM000002CE20QHX.html)