Headlight Relay Circuit
LIGHTING: LIGHTING SYSTEM: Headlight Relay Circuit
Headlight Relay Circuit
DESCRIPTION
The headlights are illuminated when the light control switch, located on the headlight dimmer switch, is turned to the HEAD position.
WIRING DIAGRAM
INSPECTION PROCEDURE
PROCEDURE
1. CHECK VEHICLE CONDITION
(a) Check whether the headlights come on.
Result:
B -- REPLACE BULB
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT RELAY)
(a) Connect the Techstream to the DLC3.
(b) Turn the ignition switch to 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.
NG -- INSPECT FUSES (H-LP LH/H-LP LO LH, H-LP RH/H-LP LO RH)
OK -- Continue to next step.
3. INSPECT HEADLIGHT DIMMER SWITCH
(a) Remove the headlight dimmer switch assembly Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the headlight dimmer switch assembly.
NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (H-LP/AMT RELAY - HEADLIGHT DIMMER SWITCH)
(a) Disconnect the F6 headlight dimmer switch connector.
(b) Measure the voltage according to the value(s) in the table below.
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)
5. INSPECT FUSES (H-LP LH/H-LP LO LH, H-LP RH/H-LP LO RH)
(a) Remove the H-LP LH/H-LP LO LH and H-LP RH/H-LP LO RH fuses from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the H-LP LH/H-LP LH LO and H-LP RH/H-LP RH LO fuses.
NG -- REPLACE FUSE
OK -- Continue to next step.
6. REPLACE BULB
(a) Temporarily replace the headlight bulb with a new or normally functioning one Disassembly.
NEXT -- Continue to next step.
7. CHECK HEADLIGHT BULB
(a) Check that the headlight (low-beam) come on.
OK:
Headlight (low-beam) come on.
NG -- CHECK HARNESS AND CONNECTOR (BATTERY - HEADLIGHT)
OK -- END (REPLACE BULB)
8. CHECK HARNESS AND CONNECTOR (BATTERY - HEADLIGHT)
(a) Disconnect the B3 and B6 headlight connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Reconnect the headlight connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
9. INSPECT RELAY (H-LP/AMT)
(a) Remove the H-LP/AMT relay from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the H-LP/AMT relay.
NG -- REPLACE RELAY
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (H-LP/AMT RELAY - HEADLIGHT, H-LP LH/H-LP LH LO FUSE)
(a) Remove the H-LP/AMT relay from the No. 2 engine room relay block.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Reinstall the H-LP/AMT relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
11. CHECK HARNESS AND CONNECTOR (H-LP/AMT RELAY - BODY GROUND)
(a) Remove the H-LP/AMT relay from the No. 2 engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the H-LP/AMT relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (H-LP/AMT RELAY - HEADLIGHT DIMMER SWITCH)
12. REPLACE BULB
(a) Temporarily replace the headlight bulb with a new or normally functioning one Disassembly.
NEXT -- Continue to next step.
13. CHECK HEADLIGHT BULB
(a) Check that the headlight (high-beam) come on.
OK:
Headlight (high-beam) come on.
NG -- INSPECT HEADLIGHT DIMMER SWITCH
OK -- END (REPLACE BULB)
14. INSPECT HEADLIGHT DIMMER SWITCH
(a) Remove the headlight dimmer switch assembly Removal.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the headlight dimmer switch assembly.
NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT - HEADLIGHT DIMMER SWITCH)