High Beam Headlight Circuit

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

DESCRIPTION

The main body ECU (multiplex network body ECU) controls the high beam headlights via the engine room junction block assembly.

WIRING DIAGRAM





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 high beam headlights illuminate.

Main Body





OK:

The high beam headlights illuminate.

NG -- CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

OK -- PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Problem Symptoms Table

2. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Using a voltmeter, check the signal reading of the engine room junction block assembly Testing and Inspection.

OK:

Output signal reading is normal

NG -- INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY (RESULTS OF SIGNAL READING CHECK) Testing and Inspection
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY POWER SOURCE AND BODY GROUND) Daytime Running Light Relay Circuit

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

4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Disconnect the 3D instrument panel junction block assembly connector.

(b) 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.

5. CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the instrument panel junction block assembly Removal.

(b) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

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

Standard Resistance:





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

6. CHECK ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Replace the engine room junction block assembly with a new or a known good one Removal.

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

OK:

The high beam headlights operate normally.

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

OK -- END (ENGINE ROOM JUNCTION BLOCK ASSEMBLY WAS DEFECTIVE)