Headlight Relay Circuit

LIGHTING (EXT): LIGHTING SYSTEM: Headlight Relay Circuit
- Headlight Relay Circuit

DESCRIPTION

The main body ECU (driver side junction block assembly) 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 ignition switch to ON.

(c) Turn the Techstream on.

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

(e) Check that the relays operate.

Main Body

Main Body:

OK:

Headlight relays operate. (Low beam headlights illuminate.)

NG -- INSPECT ENGINE ROOM JUNCTION BLOCK ASSEMBLY

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

2. INSPECT 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 1A-1.

(c) Connect a negative (-) lead from the battery to terminal 1F-17.

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

Standard Voltage:





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

3. CHECK HARNESS AND CONNECTOR (BATTERY - ENGINE ROOM JUNCTION BLOCK ASSEMBLY)

(a) Disconnect the 1A power distributor (engine room junction block assembly) connector.





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

Standard Voltage:





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

4. CHECK HARNESS AND CONNECTOR (ENGINE ROOM JUNCTION BLOCK ASSEMBLY - MAIN BODY ECU)

(a) Disconnect the 1F power distributor (engine room junction block assembly) connector.





(b) Disconnect the 2G main body ECU (driver side junction block assembly) connector.

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

Standard Resistance:





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Text in Illustration:

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

OK -- REPLACE MAIN BODY ECU (DRIVER SIDE JUNCTION BLOCK ASSEMBLY) Components