LO-Beam Headlight Does Not Illuminate

LIGHTING: LIGHTING SYSTEM: LO-beam Headlight does not Illuminate

LO-beam Headlight does not Illuminate

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTE: First perform the communication function inspections in HOW TO PROCEED WITH TROUBLESHOOTING to confirm that there are no CAN communication malfunctions before troubleshooting this symptom.
HINT: If a discharge headlight bulb's condition cannot be determined through a visual check, replace it with a normally functioning bulb or interchange the left and right bulbs and check its condition.

PROCEDURE

1. CHECK HEADLIGHT TYPE
(a) Check the headlight type.

Result





B -- CHECK FOR DTC
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING INTELLIGENT TESTER OR TECHSTREAM (HEADLIGHT LO)
(a) Using the intelligent tester or Techstream, perform the Active Test.
(1) Intelligent tester

BODY NO. 5





(2) Techstream

Body No. 5





OK:
Low beam headlight illumination condition is switched by Active Test.
NG -- CHECK MULTIPLEX NETWORK FRONT LIGHT ECU (HRLY VOLTAGE)
OK -- Continue to next step.
3. READ VALUE USING INTELLIGENT TESTER OR TECHSTREAM (HEADLIGHT DIMMER SWITCH)
(a) Using the intelligent tester or Techstream, read the Data List.
(1) Intelligent tester

COMBI SW





(2) Techstream

Combination Switch





OK:
Tester display changes according to the switch operation.
NG -- CHECK WINDSHIELD WIPER SWITCH (OPERATION)
OK -- REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY
4. CHECK MULTIPLEX NETWORK FRONT LIGHT ECU (HRLY VOLTAGE)





(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK FRONT LIGHT ECU - ENGINE ROOM NO. 2 RELAY BLOCK)
OK -- Continue to next step.
5. CHECK ENGINE ROOM NO. 2 RELAY BLOCK





(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE ENGINE ROOM NO. 2 RELAY BLOCK
OK -- Continue to next step.
6. INSPECT ENGINE ROOM NO. 2 RELAY BLOCK





(a) Disconnect the 2A relay block connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ENGINE ROOM NO. 2 RELAY BLOCK
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - HEADLIGHT)





(a) for HID Headlight (w/o Driver Monitor Camera):
(1) Disconnect the 2A relay block connector.
(2) Disconnect the B3 and B13 light connectors.
(3) Measure the resistance according to the value(s) in the table below.
Standard resistance:

for LH





for RH





(b) for HID Headlight (w/ Driver Monitor Camera):
(1) Disconnect the 2A relay block connector.
(2) Disconnect the B1 and B11 light connectors.
(3) 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 CONTROL ECU (OPERATION)
(a) Temporarily replace the headlight control ECU with a new or normally functioning one Disassembly.
(b) Check the Lo-beam headlight operation.
OK:
Lo-beam headlight operation is normal.
NG -- CHECK HEADLIGHT ASSEMBLY (OPERATION)
OK -- END (REPLACE HEADLIGHT CONTROL ECU)
9. CHECK HEADLIGHT ASSEMBLY (OPERATION)
(a) Temporarily replace the headlight with a new or normally functioning one Removal.
(b) Check the Lo-beam headlight operation.
OK:
Lo-beam headlight operation is normal.
NG -- REPLACE MULTIPLEX NETWORK FRONT LIGHT ECU
OK -- END (REPLACE HEADLIGHT ASSEMBLY)
10. CHECK WINDSHIELD WIPER SWITCH (OPERATION)
(a) Temporarily replace the windshield wiper switch with a new or normally functioning one Removal.
(b) Check the Lo-beam headlight operation.
OK:
Lo-beam headlight operation is normal.
NG -- CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK FRONT LIGHT ECU - WINDSHIELD WIPER SWITCH)
OK -- END (REPLACE WINDSHIELD WIPER SWITCH)
11. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK FRONT LIGHT ECU - ENGINE ROOM NO. 2 RELAY BLOCK)





(a) Disconnect the A50 ECU connector.
(b) Disconnect the 2G relay block connector.
(c) 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.
12. CHECK ENGINE ROOM NO. 2 RELAY BLOCK





(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- INSPECT ENGINE ROOM NO. 2 RELAY BLOCK
OK -- REPLACE ENGINE ROOM NO. 2 RELAY BLOCK
13. INSPECT ENGINE ROOM NO. 2 RELAY BLOCK





(a) Disconnect the 2E relay block connector.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ENGINE ROOM NO. 2 RELAY BLOCK
OK -- REPAIR OR REPLACE HARNESS OR CONNECTOR (BATTERY - ENGINE ROOM NO. 2 RELAY BLOCK)
14. CHECK HARNESS AND CONNECTOR (MULTIPLEX NETWORK FRONT LIGHT ECU - WINDSHIELD WIPER SWITCH)





(a) Disconnect the A50 ECU connector.
(b) Disconnect the L25 switch connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE MULTIPLEX NETWORK FRONT LIGHT ECU
15. CHECK FOR DTC
(a) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B2430 or B2431 output does not occur.
NG -- GO TO DIAGNOSTIC TROUBLE CODE CHART
OK -- REPLACE HEADLIGHT CONTROL ECU