LIGHTING SYSTEM > Low Beam Headlight Circuit

for Preparation Click here


DESCRIPTION

The main body ECU (multiplex network body ECU) controls the headlight relays located within the No. 1 integration relay.

WIRING DIAGRAM


for LED Headlight:

E223763E03


except LED Headlight:

E196592E05


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

1.PERFORM ACTIVE TEST USING INTELLIGENT TESTER

  1. Connect the intelligent tester to the DLC3.

  1. Turn the power switch on (IG).

  1. Turn the intelligent tester on.

  1. Enter the following menus: Body / Main Body / Active Test.

  1. Check that the relays operate.

    Main Body 
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Headlight Relay
    		Headlight relays
    		ON/OFF
    		-

    OK:
    Headlight relays operate. (Low beam headlights illuminate.)



NG
Go to step 2
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)  

2.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - AUXILIARY BATTERY AND BODY GROUND)

  1. Disconnect the 1G and 1H No. 1 integration relay connectors.

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

    Standard Voltage:
    Tester Connector
    		Condition
    		Specified Condition
    1G-14 (IG1) - Body ground
    		Power switch on (IG)
    		11 to 14 V
    1H-7 (BATT) - Body ground
    		Power switch off
    		11 to 14 V

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1H-3 (GND2) - Body ground
    		Always
    		Below 1 Ω
    1G-22 (GND1) - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


3.CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK)

  1. Disconnect the 1G No. 1 integration relay connector.

  1. Disconnect the 2C instrument panel junction block assembly connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1G-9 (HL4) - 2C-32
    		Always
    		Below 1 Ω
    1G-9 (HL4) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY


    E182506E18

  1. Remove the instrument panel junction block assembly.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    2C-32 - A-15 (HRLY)
    		Always
    		Below 1 Ω
    2C-32 - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *a
    		Component without harness connected
    (Instrument Panel Junction Block Assembly)



NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK


5.REPLACE NO. 1 INTEGRATION RELAY

  1. Replace the combination meter assembly with a new or a known good one (Click here).

  1. Check that the low beam headlights operate normally.

    OK:
    Low beam headlights operate normally.



NG
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (Click here)
OK

END