Headlight (HI-Beam) Circuit

LIGHTING: LIGHTING SYSTEM: Headlight (HI-BEAM) Circuit

Headlight (HI-BEAM) Circuit

DESCRIPTION

The main body ECU receives light control switch and dimmer switch information signals from the headlight dimmer switch, and illuminates the headlight high beam.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT)
(a) Operate the Techstream according to the steps on the display and select "Active Test".

Main Body





OK:
Headlight (High) turns on / off.
NG -- INSPECT FUSE (HEAD LH, HEAD RH)
OK -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2. INSPECT FUSE (HEAD LH, HEAD RH)
(a) Remove the HEAD LH and HEAD RH fuse from the engine room junction block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE FUSE
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (HEADLIGHT HIGH BULB - BATTERY)




(a) for LH:
(1) Disconnect the A8 headlight connector.
(2) Measure the voltage according to the value(s) in the table below.
Standard voltage:









(b) for RH:
(1) Disconnect the A9 headlight connector.
(2) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- INSPECT HEADLIGHT DIMMER RELAY (DIM)
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT HIGH BULB - BODY GROUND)
4. INSPECT HEADLIGHT DIMMER RELAY (DIM)




(a) Remove the headlight dimmer relay from the engine room relay block.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE HEADLIGHT DIMMER RELAY
OK -- Continue to next step.
5. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - BATTERY)




(a) Remove the headlight dimmer relay from the engine room relay block.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER RELAY - HEADLIGHT HIGH BULB)




(a) Remove the headlight dimmer relay from the engine room relay block.
(b) for LH:
(1) Disconnect the A8 headlight connector.
(2) Measure the resistance according to the value(s) in the table below.
Standard resistance:





(c) for RH:
(1) Disconnect the A9 headlight connector.
(2) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
7. CHECK HEADLIGHT (HIGH BEAM)




(a) Disconnect the DB ECU connector.
(b) Using a service wire, connect DB-19 (DIM) on the wire harness side and body ground.
(c) Check that the headlight high beam illuminates.
OK:
Headlight high beam illuminates.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEADLIGHT DIMMER RELAY - MAIN BODY ECU)
OK -- REPLACE MAIN BODY ECU