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.

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 -- INSPECT POWER DISTRIBUTOR ENGINE ROOM JUNCTION BLOCK ASSEMBLY

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

2. INSPECT POWER DISTRIBUTOR ENGINE ROOM JUNCTION BLOCK ASSEMBLY

(a) Remove the power distributor (engine room junction block assembly) from the engine room relay block Components.





(b) Connect a positive (+) lead from the battery to terminal 3A-1

(c) Connect a negative (-) lead from the battery to terminals 3C-13 and 3C-17.

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

Standard Voltage:





Text in Illustration





NG -- REPLACE POWER DISTRIBUTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY) Components
OK -- Continue to next step.

3. CHECK HARNESS AND CONNECTOR (BATTERY - POWER DISTRIBUTOR)

(a) Disconnect the 3A power distributor (engine room junction block assembly) connector.





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

Standard Voltage:





Text in Illustration





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

4. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR - BODY GROUND)

(a) Disconnect the 3C power distributor (engine room junction block assembly) connector.





(b) 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.

5. CHECK HARNESS AND CONNECTOR (POWER DISTRIBUTOR - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 3C power distributor (engine room junction block assembly) connector.





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

(c) 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.

6. 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 -- REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Components