Headlight Relay Circuit

LIGHTING: LIGHTING SYSTEM: Headlight Relay Circuit
- Headlight Relay Circuit

DESCRIPTION

When the light control switch, located on the headlight dimmer switch, is turned to the HEAD position, the HEAD relay illuminates the headlights.

WIRING DIAGRAM





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 the operation.

Main Body (Main Body ECU)





OK:

Headlight comes on.

OK -- CHECK WIRE HARNESS (HEADLIGHT DIMMER SWITCH - MAIN BODY ECU)
NG -- Continue to next step.

2. INSPECT FUSE (HEAD LL, HEAD RL)

(a) Remove the HEAD LL fuse and HEAD RL fuse from the engine room No. 2 relay block.

(b) Measure the resistance of the fuses.

Standard resistance:

Below 1 Ohms

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

3. INSPECT HEADLIGHT RELAY (Marking: HEAD)





(a) Remove the headlight relay from the engine room No. 2 relay block.

(b) Measure the resistance of the relay.

Standard resistance:





NG -- REPLACE HEADLIGHT RELAY
OK -- Continue to next step.

4. INSPECT BULB (HEADLIGHT BULB)





(a) Remove the headlight bulbs (LOW).

(b) Connect the positive (+) lead from the battery to terminal 2 and the negative (-) lead to terminal 1, then check that the bulb illuminates.

OK:

Bulb illuminates.

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

5. CHECK WIRE HARNESS (MAIN BODY ECU - BATTERY)





(a) Disconnect the E15 main body ECU connector.

(b) Measure the voltage of the wire harness side connector.

Standard voltage:





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

6. CHECK INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)





(a) Measure the voltage of the main body ECU.

Standard voltage:





NG -- REPLACE INSTRUMENT PANEL JUNCTION BLOCK (MAIN BODY ECU)

OK -- REPAIR OR REPLACE HARNESS AND CONNECTOR (HEAD RELAY - HEADLIGHT BULB AND BODY GROUND)

7. CHECK WIRE HARNESS (HEADLIGHT DIMMER SWITCH - MAIN BODY ECU)





(a) Disconnect the E17 main body ECU connector.

(b) Disconnect the E12 headlight dimmer switch connector.

(c) Measure the resistance of the wire harness side connectors.

Standard resistance:





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

8. INSPECT HEADLIGHT DIMMER SWITCH





(a) Disconnect the E12 headlight dimmer switch.

(b) Measure the resistance of the switch.

Standard resistance:





NG -- REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY

OK -- REPAIR OR REPLACE HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - BODY GROUND)