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 H-LP/AMT relay illuminates the headlights.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (HEAD LIGHT)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch ON.
(c) Turn the tester on.
(d) Enter the following menus: Body Electrical / Main Body / Active Test / Headlight Relay.
(e) Check the headlight (Low-beam) while operating the headlight relay using the tester.
Main Body (Main Body ECU):






OK:
The headlight (Low-beam) comes on when operating it through the Techstream.
OK -- INSPECT HEADLIGHT DIMMER SWITCH
NG -- Continue to next step.
2. INSPECT FUSE (H-LP RH/H-LP LO RH, H-LP LH/H-LP LO LH)
(a) Remove the H-LP RH/H-LP LO RH and H-LP LH/H-LP LO LH fuses from the engine room relay block.
(b) Measure the resistance.
Standard resistance:
Below 1 Ohms
(c) Reinstall the H-LP RH/H-LP LO RH and H-LP LH/H-LP LO LH fuses
NG -- REPLACE FUSE
OK -- Continue to next step.
3. INSPECT BULB (HEADLIGHT BULB)




(a) Disconnect the B4 and B6 headlight connectors.
(b) Apply battery voltage to the terminals and check that the headlight illuminates.
Standard:





(c) Reconnect the headlight connectors.
NG -- REPLACE BULB
OK -- Continue to next step.
4. INSPECT H-LP/AMT RELAY




(a) Remove the H-LP/AMT relay from the engine room relay block No. 2.
(b) Measure the resistance.
Standard resistance:





(c) Reinstall the H-LP/AMT relay.
NG -- REPLACE H-LP/AMT RELAY
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (FUSE - HEADLIGHT BULB)




(a) Disconnect the B4 and B6 headlight bulb connectors.
(b) Measure the voltage.
Standard voltage:





(c) Reconnect the headlight bulb connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (HEADLIGHT - H-LP/AMT RELAY)




(a) Remove the H-LP/AMT relay from the engine room relay block No. 2.
(b) Measure the voltage.
Standard voltage:





(c) Reinstall the H-LP/AMT relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT - HEADLIGHT DIMMER SWITCH)
7. INSPECT HEADLIGHT DIMMER SWITCH




(a) Remove the headlight dimmer switch.
(b) Inspect the light control switch.
(c) Measure the resistance.
Standard resistance:





(d) Inspect the headlight dimmer switch.
(e) Measure the resistance.
Standard resistance:





(f) Reinstall the headlight dimmer switch.
NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (H-LP/AMT RELAY - HEADLIGHT DIMMER SWITCH)




(a) Disconnect the D4 headlight dimmer switch connector.
(b) Measure the voltage.
Standard voltage:





(c) Reconnect the headlight dimmer switch connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT DIMMER SWITCH - BODY GROUND)