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 integration relay.

WIRING DIAGRAM

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 (INTEGRATION RELAY - BATTERY AND BODY GROUND)

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE How To Proceed With Troubleshooting

2. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BATTERY AND BODY GROUND)

(a) Disconnect the 1H integration relay connector.

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

Standard Voltage:

Standard Resistance:

Text in Illustration

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

Standard Resistance:

Text in Illustration

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

3. CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 1G 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 INTEGRATION NO.1 RELAY

(a) Temporarily replace the integration relay with a new or normally functioning one Components.

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

OK:

Low beam headlights operate normally.

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

OK -- END