Low Beam Headlight Circuit

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

DESCRIPTION

The headlight relay is turned on by operating the headlight switch.

When the theft deterrent system is activated, it causes the ECU to turn the headlight relay on and off repeatedly at approximately 0.25 second intervals to flash the headlights.

In this condition, if any of the following operations is performed, the ECU turns the headlight relay off to stop the headlight from flashing:

* Unlock the driver door with a key.

* Turn the engine switch on (ACC or IG).

* Unlock the doors with the wireless door lock control system.

WIRING DIAGRAM









INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

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

(e) Check that the relays operate.

Body (Main Body ECU RH)





OK:

Low beam headlights illuminate.

NG -- INSPECT FUSE (H-LP L LWR, H-LP R LWR)

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

2. INSPECT FUSE (H-LP L LWR, H-LP R LWR)

(a) Remove the H-LP L LWR fuse from the No. 2 engine room relay block.

(b) Remove the H-LP R LWR fuse from the No. 2 engine room relay block.

(c) Measure the resistance of the fuses.

Standard Resistance:

Below 1 Ohms

NG -- REPLACE FUSE
OK -- Continue to next step.

3. INSPECT HEAD LP RELAY

(a) Remove the HEAD LP relay from the engine room No. 1 relay block.





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

Standard Resistance:





NG -- REPLACE HEAD LP RELAY
OK -- Continue to next step.

4. CHECK HARNESS AND CONNECTOR (MAIN BODY ECU RH - BATTERY)

(a) Disconnect the RL main body ECU RH 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.

5. CHECK HARNESS AND CONNECTOR (HEADLIGHT (LOW LH OR LOW RH) - BATTERY AND BODY GROUND)

(a) Check the wire harness between the headlight (Low LH) and battery, and the headlight (Low LH) and body ground.





(1) Disconnect the B12 headlight connector.

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

Standard Voltage:





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

Standard Resistance:





Text in Illustration





(b) Check the wire harness between the headlight (Low RH) and battery, and the headlight (Low RH) and body ground.





(1) Disconnect the B2 headlight connector.

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

Standard Voltage:





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

Standard Resistance:





Text in Illustration





NG -- CHECK HARNESS AND CONNECTOR (HEADLIGHT (LOW LH OR LOW RH) - HEAD LP RELAY)

OK -- REPLACE HEADLIGHT ASSEMBLY (LOW LH OR LOW RH) Components

6. CHECK HARNESS AND CONNECTOR (HEADLIGHT (LOW LH OR LOW RH) - HEAD LP RELAY)

(a) Check the harness and the connectors between the headlight (Low LH or Low RH) and the HEAD LP relay.





(1) Disconnect the B12 headlight connector.

(2) Remove the HEAD LP relay from the engine room No. 1 relay block.

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

Standard Resistance (Check for Open):





Standard Resistance (Check for Short):





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

OK -- REPLACE MAIN BODY ECU RH (COWL SIDE JUNCTION BLOCK RH)