Lighting System Headlight Signal Circuit


DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

READ VALUE USING INTELLIGENT TESTER (HEADLIGHT)

CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - HEADLIGHT LEVELING ECU ASSEMBLY AND BODY GROUND)

INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY

LIGHTING SYSTEM - Headlight Signal Circuit


DESCRIPTION

The headlight leveling ECU receives the low beam headlight on/off state information from the headlight dimmer switch to control the headlight beam level control system.
HINT:
Before performing troubleshooting of the automatic headlight beam level control system, check that the low beam headlights operate normally.

WIRING DIAGRAM


Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Lighting.Lighting System.Lighting System Headlight Signal Circuit


INSPECTION PROCEDURE

HINT:
After replacing the headlight leveling ECU, initialization of the ECU is necessary (Toyota Fortuner RM000002CE402CX.html).
1.READ VALUE USING INTELLIGENT TESTER (HEADLIGHT)

  1. Using the intelligent tester, read the Data List (Toyota Fortuner RM000000PKV08JX.html).

    HL Auto Leveling
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    Headlight Low Beam State
    		Low beam headlight state / ON or OFF
    		ON: Low beam headlights on
    OFF: Low beam headlights off
    		-
    OK:
    The display is as specified in the normal condition column.


NG
Go to step 2
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Toyota Fortuner RM000002CE208UX.html)

2.CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH ASSEMBLY - HEADLIGHT LEVELING ECU ASSEMBLY AND BODY GROUND)

  1. Disconnect the C29 headlight dimmer switch connector.

  1. Disconnect the H17 headlight leveling ECU connector.

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

    Standard Resistance:
    for LHD
    Tester Connection
    		Condition
    		Specified Condition
    C29-20 (H) - H17-3 (B2)
    		Always
    		Below 1 Ω
    C29-12 (EL) - Body ground
    		Always
    		Below 1 Ω
    H17-3 (B2) - Body ground
    		Always
    		10 kΩ or higher
    for RHD
    Tester Connection
    		Condition
    		Specified Condition
    C29-11 (H) - H17-3 (B2)
    		Always
    		Below 1 Ω
    C29-19 (EL) - Body ground
    		Always
    		Below 1 Ω
    H17-3 (B2) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.INSPECT HEADLIGHT DIMMER SWITCH ASSEMBLY


    Toyota Fortuner. Ggn50, 60 Kun51, 61 Tgn51 Lan50.Lighting.Lighting System.Lighting System Headlight Signal Circuit

  1. Remove the headlight dimmer switch (Toyota Fortuner RM0000014MA002X.html).

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

    Standard Resistance:
    for LHD
    Tester Connection
    		Switch Condition
    		Specified Condition
    20 (H) - 12 (EL)
    		Headlight dimmer switch head
    		Below 1 Ω
    Headlight dimmer switch off
    		10 kΩ or higher
    for RHD
    Tester Connection
    		Switch Condition
    		Specified Condition
    11 (H) - 19 (EL)
    		Headlight dimmer switch head
    		Below 1 Ω
    Headlight dimmer switch off
    		10 kΩ or higher


NG
REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY (Toyota Fortuner RM0000014MA002X.html)
OK

REPLACE HEADLIGHT LEVELING ECU ASSEMBLY (Toyota Fortuner RM000000ZQ500LX.html)