Last Modified: 08-21-2023 6.11:8.1.0 Doc ID: RM100000001AYB3
Model Year Start: 2019 Model: Avalon Prod Date Range: [04/2018 -           ]
Title: LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model with Cornering Light): B2439,B243A; Headlight LH Circuit; 2019 - 2022 MY Avalon [04/2018 -        ]

DTC

B2439

Headlight LH Circuit

DTC

B243A

Headlight RH Circuit

DESCRIPTION

The headlight ECU sub-assembly LH and headlight ECU sub-assembly RH internally boost the power supply voltage to ensure a constant supplied current for the low beam LED of their respective headlight.

By monitoring the LED power supply voltage, abnormal current and malfunctions can be detected.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B2439

Headlight LH Circuit

Detection condition:

  • All of the following conditions are met:
    • Engine switch on (IG)
    • Low beam headlights on

Malfunction status:

  • Headlight assembly malfunction
  • Open/short in low beam circuit

Malfunction duration:

  • 10 seconds or more
  • Headlight ECU sub-assembly LH
  • Headlight assembly LH

Headlight ECU sub-assembly LH

B243A

Headlight RH Circuit

Detection condition:

  • All of the following conditions are met:
    • Engine switch on (IG)
    • Low beam headlights on

Malfunction status:

  • Headlight assembly malfunction
  • Open/short in low beam circuit

Malfunction duration:

  • 10 seconds or more
  • Headlight ECU sub-assembly RH
  • Headlight assembly RH

Headlight ECU sub-assembly RH

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • If the headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information the headlight ECU sub-assembly LH.

    Click here 2019 - 2022 MY Avalon [04/2018 -        ]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model with Cornering Light): INITIALIZATION

  • If the headlight assembly LH has been replaced, it is necessary to synchronize the vehicle information the headlight ECU sub-assembly LH.

    Click here 2019 - 2022 MY Avalon [04/2018 -        ]; LIGHTING (EXT): LIGHTING SYSTEM (for Gasoline Model with Cornering Light): INITIALIZATION

PROCEDURE

1.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs

Body Electrical > HL AutoLeveling (Sub) > Clear DTCs

NEXT

2.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(f) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

Body Electrical > HL AutoLeveling (Sub) > Trouble Codes

OK:

DTC B2439 and B243A are not output.

Result

Proceed to

OK

A

NG (DTC B2439 is output)

B

NG (DTC B243A is output)

C
A

USE SIMULATION METHOD TO CHECK

C

GO TO STEP 6

B

3.

CHECK HEADLIGHT ASSEMBLY LH

(a) Remove each headlight ECU sub-assembly, interchange the headlight assembly LH with RH and connect the connectors.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; LIGHTING (EXT): HEADLIGHT ASSEMBLY: REMOVAL

NEXT

4.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs

Body Electrical > HL AutoLeveling (Sub) > Clear DTCs

NEXT

5.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(f) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

Body Electrical > HL AutoLeveling (Sub) > Trouble Codes

Result

Proceed to

DTC B2439 is output

A

DTC B243A is output

B
A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY LH

B

REPLACE HEADLIGHT ASSEMBLY LH

6.

CHECK HEADLIGHT ASSEMBLY RH

(a) Remove each headlight ECU sub-assembly, interchange the headlight assembly RH with LH and connect the connectors.

Click here 2019 - 2022 MY Avalon Avalon HV [04/2018 -        ]; LIGHTING (EXT): HEADLIGHT ASSEMBLY: REMOVAL

NEXT

7.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs

Body Electrical > HL AutoLeveling (Sub) > Clear DTCs

NEXT

8.

CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Operate the light control switch to turn on the low beam headlights and wait 10 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / HL AutoLeveling or HL AutoLeveling (Sub) / Trouble Codes.

(f) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

Body Electrical > HL AutoLeveling (Sub) > Trouble Codes

Result

Proceed to

DTC B243A is output

A

DTC B2439 is output

B
A

REPLACE HEADLIGHT ECU SUB-ASSEMBLY RH

B

REPLACE HEADLIGHT ASSEMBLY RH