Component Tests and General Diagnostics
LIGHTING: LIGHTING SYSTEM: Headlight Signal Circuit
Headlight Signal 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 illuminate.
Result:
C -- INSPECT FUSE (H-LP LH HI, H-LP RH HI)
B -- INSPECT FUSE (H-LP LH LO, H-LP RH LO)
A -- Continue to next step.
2. INSPECT FUSE (H-LP MAIN)
(a) Remove the H-LP MAIN fuse 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 MAIN fuse.
NG -- REPLACE FUSE
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (BATTERY - H-LP RELAY)
(a) Remove the H-LP relay from the engine room relay block.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Reinstall the H-LP relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
4. INSPECT H-LP RELAY
(a) Remove the H-LP 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 relay.
NG -- REPLACE H-LP RELAY
OK -- Continue to next step.
5. INSPECT HEADLIGHT DIMMER SWITCH
(a) Remove the headlight dimmer switch assembly.
(b) Inspect the light control switch.
(1) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Inspect the headlight dimmer switch.
(1) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(d) Reinstall the headlight dimmer switch assembly.
NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT DIMMER SWITCH)
(a) Disconnect the C11 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)
7. INSPECT FUSE (H-LP LH LO, H-LP RH LO)
(a) Remove the H-LP LH LO and H-LP RH LO 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 LO and H-LP RH LO fuses.
NG -- REPLACE FUSE
OK -- Continue to next step.
8. INSPECT BULB (LOW-BEAM)
(a) Remove the headlight (Low-beam ).
(b) Apply battery voltage to the terminals and check that the headlight illuminates.
OK:
(c) Reinstall the headlight (Low-beam).
NG -- REPLACE BULB
OK -- Continue to next step.
9. CHECK HARNESS AND CONNECTOR (H-LP RELAY - H-LP LH LO, H-LP RH LO FUSE)
(a) Remove the H-LP relay from the engine room relay block.
(b) Remove the H-LP LH LO and H-LP RH LO fuses from the engine room relay block.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(d) Reinstall the H-LP LH LO and H-LP RH LO fuses.
(e) Reinstall the H-LP relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
10. CHECK HARNESS AND CONNECTOR (H-LP LH LO AND H-LP RH LO FUSE - HEADLIGHT (LOW-BEAM))
(a) Disconnect the A27 and A28 headlight (Low-beam) connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Reconnect the headlight (Low-beam) connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT (LOW-BEAM) - BODY GROUND)
11. INSPECT FUSE (H-LP LH HI, H-LP RH HI)
(a) Remove the H-LP LH HI and H-LP RH HI 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 HI and H-LP RH HI fuses.
NG -- REPLACE FUSE
OK -- Continue to next step.
12. INSPECT BULB (HI-BEAM)
(a) Remove the headlight (Hi-beam ).
(b) Apply battery voltage to the terminals and check that the headlight illuminates.
OK:
(c) Reinstall the headlight (Hi-beam).
NG -- REPLACE BULB
OK -- Continue to next step.
13. INSPECT HEADLIGHT (SYSTEM VOLTAGE)
(a) Disconnect the A25 and A26 headlight (Hi-beam) connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(c) Reconnect the headlight (Hi-beam) connectors.
NG -- CHECK HARNESS AND CONNECTOR (DIMMER RELAY - H-LP RELAY, H-LP LH HI AND H-LP RH HI FUSE)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT (HI) - BODY GROUND)
14. CHECK HARNESS AND CONNECTOR (DIMMER RELAY - H-LP RELAY, H-LP LH HI AND H-LP RH HI FUSE)
(a) Remove the DIMMER and H-LP relay from the engine room relay block.
(b) Remove the H-LP LH HI and H-LP RH HI fuses from the engine room relay block.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(d) Reinstall the H-LP LH HI and H-LP RH HI fuses.
(e) Reinstall the DIMMER relay.
(f) Reinstall the H-LP relay.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
15. INSPECT DIMMER RELAY
(a) Remove the DIMMER 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 DIMMER relay.
NG -- REPLACE DIMMER RELAY
OK -- Continue to next step.
16. CHECK HARNESS AND CONNECTOR (H-LP LH HI AND H-LP RH HI FUSE - HEADLIGHT (HI-BEAM))
(a) Remove the H-LP LH HI and H-LP RH HI fuses from the engine room relay block.
(b) Disconnect the A25 and A26 headlight assembly connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(d) Reinstall the H-LP LH HI and H-LP RH HI fuses.
(e) Reconnect the headlight (Hi-beam) connectors.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
17. INSPECT HEADLIGHT DIMMER SWITCH
(a) Remove the headlight dimmer switch assembly.
(b) Inspect the headlight dimmer switch.
(1) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reinstall the headlight dimmer switch.
NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
18. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - BODY GROUND)
(a) Disconnect the C11 headlight dimmer switch connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:
(c) Reconnect the headlight dimmer switch connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (DIMMER RELAY - HEADLIGHT DIMMER SWITCH)