B2431
LIGHTING: LIGHTING SYSTEM: B2430,B2431: LED Headlight LH Circuit Malfunction
B2431 - LED Headlight RH Circuit Malfunction
DESCRIPTION
This DTC is output when the low beam headlights do not illuminate, or a malfunction is detected in the communication between the headlight assembly and the AFS ECU. The multiplex network front light ECU (front controller) illuminates and turns off the low beam headlight via the engine room junction block assembly (headlight relay LH, headlight relay RH). The multiplex network front light ECU (front controller) detects the state of the headlight dimmer switch from the windshield wiper switch assembly via CAN communication. Additionally, the AFS ECU detects the illumination condition of the low beam headlights.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
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.
PROCEDURE
1. CHECK HEADLIGHT
(a) Check that the low beam headlights illuminate.
Result
B -- CHECK HARNESS AND CONNECTOR
A -- Continue to next step.
2. PERFORM ACTIVE TEST USING TECHSTREAM (HEADLIGHT LO)
(a) Using the Techstream, perform the Active Test.
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 TECHSTREAM (HEADLIGHT DIMMER SWITCH)
(a) Using the Techstream, read the Data List.
Combination Switch
OK:
Techstream display changes according to the switch operation.
NG -- REPLACE HEADLIGHT DIMMER SWITCH ASSEMBLY Removal
OK -- Continue to next step.
4. 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 -- Continue to next step.
5. CHECK WINDSHIELD WIPER SWITCH (OPERATION)
(a) Temporarily replace the windshield wiper switch with a new or normally functioning one Removal.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B2430 or B2431 output does not occur.
NG -- REPLACE MULTIPLEX NETWORK FRONT LIGHT ECU
OK -- END (REPLACE WINDSHIELD WIPER SWITCH) Removal
6. 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.
7. CHECK ENGINE ROOM NO. 2 RELAY BLOCK
(a) Measure the voltage according to the value(s) in the table below.
Standard voltage:
(b) Disconnect the 2A relay block connector.
(c) 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.
8. CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 2 RELAY BLOCK - HEADLIGHT)
(a) Disconnect the 2A relay block connector.
(b) Disconnect the B1 and B11 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.
9. CHECK HEADLIGHT CONTROL ECU (OPERATION)
(a) Temporarily replace the headlight control ECU with a new or normally functioning one Disassembly.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B2430 or B2431 output does not occur.
NG -- REPLACE HEADLIGHT ASSEMBLY Removal
OK -- END (REPLACE HEADLIGHT CONTROL ECU) Disassembly
10. 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.
11. 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
12. 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)
13. CHECK HARNESS AND CONNECTOR
(a) Disconnect the B1 and B11 light connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:
for LH
for RH
NG -- CHECK HARNESS AND CONNECTOR (AFS ECU - HEADLIGHT)
OK -- Continue to next step.
14. CHECK HEADLIGHT CONTROL ECU (OPERATION)
(a) Temporarily replace the headlight control ECU with a new or normally functioning one Disassembly.
(b) Check for DTC Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC B2430 or B2431 output does not occur.
NG -- REPLACE HEADLIGHT ASSEMBLY Removal
OK -- END (REPLACE HEADLIGHT CONTROL ECU) Disassembly
15. CHECK HARNESS AND CONNECTOR (AFS ECU - HEADLIGHT)
(a) Disconnect the A37 ECU connector.
(b) Disconnect the B1 and B11 light connectors.
(c) Measure the resistance to the according value(s) in the table below.
Standard resistance:
for LH
for RH
(d) Reconnect the A37 ECU connector.
(e) Measure the voltage to the according value(s) in the table below.
Standard voltage:
for LH
for RH
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE AFS ECU Removal