Low Beam Headlight Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Low Beam Headlight Circuit
- Low Beam Headlight Circuit

DESCRIPTION

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

WIRING DIAGRAM

1. for LED Headlight:





2. except LED Headlight:





INSPECTION PROCEDURE

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

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the power switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Main Body / Active Test.

(e) Check that the relays operate.

Main Body





OK:

Headlight relays operate. (Low beam headlights illuminate.)

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

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Exterior Lighting System

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

(a) Disconnect the 1G and 1H No. 1 integration relay connectors.

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

Standard Voltage:





Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

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

(a) Disconnect the 1G No. 1 integration relay connector.

(b) Disconnect the 2C instrument panel junction block assembly connector.

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

Standard Resistance:





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly.





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

Standard Resistance:





Text in Illustration





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY
OK -- Continue to next step.

5. REPLACE NO. 1 INTEGRATION RELAY

(a) Replace the No. 1 integration relay with a new or a known good one Removal.

(b) Check that the low beam headlights operate normally.

OK:

Low beam headlights operate normally.

NG -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Removal

OK -- END (NO. 1 INTEGRATION RELAY WAS DEFECTIVE)