Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Variation Code not Written (B2451)

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Exterior / Lighting (ext) / Lighting System (w/ Automatic Headlight Beam Level Control System) / Variation Code not Written (B2451)

DESCRIPTION

The No. 1 headlight ECU sub-assembly LH stores this DTC if the vehicle specifications have not been stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

B2451

Variation Code not Written
  • The engine switch is on (IG).
  • Vehicle specifications have not been stored
  • -

No. 1 headlight ECU sub-assembly LH

AFS

CAUTION / NOTICE / HINT

NOTICE:

  • If the No. 1 headlight ECU sub-assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the No. 1 headlight ECU sub-assembly LH.

    Click here

  • If the headlight assembly LH has been replaced, it is necessary to synchronize the vehicle information and initialize the No. 1 headlight ECU sub-assembly LH.*

    Click here

  • When replacing the No. 1 headlight ECU sub-assembly LH, always replace it with a new one. If a No. 1 headlight ECU sub-assembly LH which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.
  • When replacing the headlight assembly LH, always replace it with a new one. If a headlight assembly LH which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.*
    • *: for TMMC Made

PROCEDURE

1.

SYNCHRONIZE VEHICLE INFORMATION

(a) Synchronize the vehicle information.

Click here

NEXT

2.

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 / AFS / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > AFS > Clear DTCs
NEXT

3.

CHECK FOR 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 / AFS / Trouble Codes.

(e) Check for DTCs.

Body Electrical > AFS > Trouble Codes

OK:

DTC B2451 is not output.

HINT:

If the No. 1 headlight ECU sub-assembly LH stores DTC B2451 even though the vehicle information has been synchronized, the No. 1 headlight ECU sub-assembly LH may be malfunctioning.

OK

END (VEHICLE SPECIFICATIONS WERE NOT STORED)
NG

REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH

    Height Sensor Initialization Incomplete (B2450)
    DESCRIPTION The No. 1 headlight ECU sub-assembly LH stores this DTC if initialization has not been performed after it was replaced. DTC No. Detection Item DTC Detection Condition Trouble Area ...

    Abnormal Height Sensor Data at Initialization (B2452)
    DESCRIPTION The No. 1 headlight ECU sub-assembly LH stores this DTC if the value from the rear height control sensor sub-assembly RH is out of range when performing initialization of the No. 1 headlig ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Air Conditioning System: Lost Communication with ECM (U0100-U0142,U0151,U0155,U0163)
    DESCRIPTION DTC No. Detection Item DTC Detection Condition Trouble Area Memory U0100 Lost Communication with ECM No communication with ECM CAN communication system ECM Memorized U0131 Lost Communication with Electric Power Steering ECU No communication with pow ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Can Communication System: Main Body ECU Communication Stop Mode
    DESCRIPTION Detection Item Symptom Trouble Area Main Body ECU Communication Stop Mode Either condition is met: "Main Body" is not displayed on the CAN Bus Check screen of the Techstream. Click here Communication system DTCs (DTCs that start with U) that correspond to "Main Bod ...

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

    © 2026 Copyright www.lexusrx.net
    0.0094