LO-Beam Headlight Does Not Illuminate

LIGHTING (EXT): LIGHTING SYSTEM: LO-beam Headlight does not Illuminate

LO-beam Headlight does not Illuminate

DESCRIPTION

The main body ECU receives a headlight switch information signal from the light control switch, and illuminates the headlight low beam.

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. READ VALUE USING TECHSTREAM (HEADLIGHT DIMMER SWITCH)
(a) Using the Techstream, read the Data List.

Main Body





OK:
When the headlight dimmer switch operation is performed, the result will be the same as above.
NG -- INSPECT HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
2. PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT)
(a) Using the Techstream, perform the Active Test.

Main Body





OK:
Headlight low beam turns on/off.
NG -- INSPECT HEADLIGHT RELAY (HEAD LO)
OK -- REPLACE MAIN BODY ECU
3. INSPECT HEADLIGHT DIMMER SWITCH




(a) Remove the headlight dimmer switch Component Tests and General Diagnostics.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPLACE HEADLIGHT DIMMER SWITCH
OK -- Continue to next step.
4. CHECK HARNESS AND CONNECTOR (HEADLIGHT DIMMER SWITCH - MAIN BODY ECU AND BODY GROUND)




(a) Disconnect the E14 switch connector.
(b) Disconnect the E1 and E2 ECU connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MAIN BODY ECU
5. INSPECT HEADLIGHT RELAY (HEAD LO)




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






NG -- REPLACE HEAD LO RELAY
OK -- Continue to next step.
6. CHECK HARNESS AND CONNECTOR (HEADLIGHT RELAY (HEAD LO) - BATTERY)




(a) Remove the HEAD LO 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.
7. CHECK HARNESS AND CONNECTOR (HEADLIGHT - HEAD LO RELAY AND BODY GROUND)




(a) Remove the HEAD LO relay from the engine room relay block.
(b) Disconnect the A40 and A46 light connectors.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:

for LH





for RH





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




(a) Disconnect the 2B ECU connector.
(b) Using a service wire, connect terminal 2B-18 (HRLY) on the wire harness side and the body ground.
(c) Check that the headlight low beam illuminates.
OK:
Headlight low beam illuminates.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (HEAD LO RELAY - MAIN BODY ECU)
OK -- REPLACE MAIN BODY ECU