DTC    B2430    LED Headlight LH Circuit Malfunction

DTC    B2431    LED Headlight RH Circuit Malfunction

for Preparation Click here


DESCRIPTION

These DTCs are stored when the low beam headlights do not illuminate, or a malfunction is detected in the communication between the headlight assembly and main body ECU (multiplex network body ECU).

DTC No.
DTC Detection Condition
Trouble Area
B2430
Any of the following conditions occur after 20 seconds have elapsed since the ignition switch was turned ON:
  1. Light control ECU malfunction
  2. Headlight unit malfunction
  3. Light control ECU power source and signal malfunction
  1. Headlight unit LH
  2. H-LP relay
  3. Harness or connector
  4. Main body ECU (multiplex network body ECU)
B2431
Any of the following conditions occur after 20 seconds have elapsed since the ignition switch was turned ON:
  1. Light control ECU malfunction
  2. Headlight unit malfunction
  3. Light control ECU power source and signal malfunction
  1. Headlight unit RH
  2. H-LP relay
  3. Harness or connector
  4. Main body ECU (multiplex network body ECU)

WIRING DIAGRAM


E301618E04


INSPECTION PROCEDURE

NOTICE:
  1. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
  2. DTC B2430 and B2431 are not stored if 20 seconds have not elapsed since the ignition switch was turned ON.
1.CHECK FOR DTC

  1. Clear the DTCs (Click here).

  1. Check for DTCs (Click here).

    Result 
    Result
    		Proceed to
    Both DTC B2430 and B2431 are not output
    		A
    Both DTC B2430 and B2431 are output
    		B
    DTC B2430 or B2431 is output
    		C


B
Go to step 2

C
Go to step 7
A

USE SIMULATION METHOD TO CHECK (Click here)  

2.INSPECT H-LP RELAY
E209495E08

  1. Remove the H-LP relay from the engine room relay block and junction block assembly.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3 - 5
    		Voltage not applied between terminals 1 and 2
    		10 kΩ or higher
    3 - 5
    		Voltage applied between terminals 1 and 2
    		Below 1 Ω
    Text in Illustration 
    *a
    		Component without harness connected
    (H-LP Relay)


NG
REPLACE H-LP RELAY
OK


3.CHECK HARNESS AND CONNECTOR (BATTERY - H-LP RELAY)

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    Relay Terminal 2 - Body ground
    		Always
    		11 to 14 V
    Relay Terminal 5 - Body ground
    		Always
    		11 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (H-LP RELAY - HEADLIGHT ASSEMBLY)

  1. Disconnect the A91 headlight assembly LH connector.

  1. Disconnect the A95 headlight assembly RH connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Relay Terminal 3 - A91-1 (LO)
    		Always
    		Below 1 Ω
    Relay Terminal 3 - A95-1 (LO)
    		Always
    		Below 1 Ω
    Relay Terminal 3 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (H-LP RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

  1. Disconnect the 3D instrument panel junction block assembly connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    Relay Terminal 1 - 3D-12
    		Always
    		Below 1 Ω
    Relay Terminal 1 - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

  1. Remove the instrument panel junction block assembly (Click here).

  1. Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.



  1. Measure the resistance according to the value(s) in the table below.


    E173038E04


    Text in Illustration 
    *a
    		Component without harness connected
    (Instrument Panel Junction Block Assembly)
    		-
    		-

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3D-12 - MB-15 (HRLY)
    		Always
    		Below 1 Ω


NG
REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY (Click here)
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (Click here)  

7.CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - H-LP RELAY)

  1. Disconnect the A91 or A95 headlight assembly connector.

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    LH Side (DTC B2430) 
    Tester Connection
    		Condition
    		Specified Condition
    A91-1 (LO) - Body ground
    		Ignition switch off, light control switch in head position
    		11 to 14 V
    RH Side (DTC B2431) 
    Tester Connection
    		Condition
    		Specified Condition
    A95-1 (LO) - Body ground
    		Ignition switch off, light control switch in head position
    		11 to 14 V


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


8.CHECK HARNESS AND CONNECTOR (HEADLIGHT ASSEMBLY - BODY GROUND)

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    LH Side (DTC B2430) 
    Tester Connection
    		Condition
    		Specified Condition
    A91-4 (E) - Body ground
    		Always
    		Below 1 Ω
    RH Side (DTC B2431) 
    Tester Connection
    		Condition
    		Specified Condition
    A95-4 (E) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.CHECK HEADLIGHT ASSEMBLY (INPUT VOLTAGE)

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    LH Side (DTC B2430) 
    Tester Connection
    		Condition
    		Specified Condition
    A91-2 (S) - Body ground
    		Ignition switch ON, light control switch in head position
    		11 to 14 V
    RH Side (DTC B2431) 
    Tester Connection
    		Condition
    		Specified Condition
    A95-2 (S) - Body ground
    		Ignition switch ON, light control switch in head position
    		11 to 14 V


NG
Go to step 11
OK


10.REPLACE HEADLIGHT UNIT

  1. Replace the headlight unit with a new or known good one (Click here).

  1. Check for DTCs (Click here).

    OK:
    DTC B2430 or B2431 is not output.


NG
REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (Click here)
OK

END (HEADLIGHT UNIT WAS DEFECTIVE) 

11.CHECK HARNESS AND CONNECTOR (MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) - HEADLIGHT ASSEMBLY)

  1. Disconnect the I12 main body ECU (multiplex network body ECU) connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    LH Side (DTC B2430) 
    Tester Connection
    		Condition
    		Specified Condition
    I12-24 (LLEW) - A91-2 (S)
    		Always
    		Below 1 Ω
    I12-24 (LLEW) - Body ground
    		Always
    		10 kΩ or higher
    RH Side (DTC B2431) 
    Tester Connection
    		Condition
    		Specified Condition
    I12-21 (RLEW) - A95-2 (S)
    		Always
    		Below 1 Ω
    I12-21 (RLEW) - Body ground
    		Always
    		10 kΩ or higher


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) (Click here)