Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: CAN Communication Failure (Message Registry) (U1000)

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Exterior / Lighting (ext) / Lighting System (w/ Automatic Headlight Beam Level Control System) / CAN Communication Failure (Message Registry) (U1000)

DESCRIPTION

The No. 1 headlight ECU sub-assembly LH stores this DTC if it detects an internal malfunction related to the CAN communication system.

for Multiple Beam Headlight

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

U1000

CAN Communication Failure (Message Registry)
  • The engine switch is on (IG).
  • CAN communication failure
  • -

No. 1 headlight ECU sub-assembly LH

AFS
for Single Beam Headlight

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

U1000

CAN Communication Failure (Message Registry)
  • The engine switch is on (IG).
  • CAN communication failure
  • -

No. 1 headlight ECU sub-assembly LH

HL AutoLeveling

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.

CONFIRM MODEL

(a) Choose the model to be inspected.

Result

Proceed to

for Multiple Beam Headlight

A

for Single Beam Headlight

B
B

GO TO STEP 4

A

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 U1000 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH

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 / Trouble Codes.

(e) Clear the DTCs.

Body Electrical > HL AutoLeveling > Clear DTCs
NEXT

5.

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 / HL AutoLeveling / Trouble Codes.

(e) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

OK:

DTC U1000 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

REPLACE NO. 1 HEADLIGHT ECU SUB-ASSEMBLY LH

    Lost Communication With Headlamp Control Module "B" (U0242)
    DESCRIPTION for Multiple Beam Headlight: The No. 1 headlight ECU sub-assembly LH communicates with the No. 1 headlight ECU sub-assembly RH via CAN communication. If communication between the No. 1 ...

    Turn Signal Switch Circuit
    DESCRIPTION The combination meter assembly receives the turn signal switch information and controls the turn signal lights. WIRING DIAGRAM CAUTION / NOTICE / HINT NOTICE: When replacing the combinati ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Sfi System: Engine Coolant Temperature Sensor 1 Circuit Short to Battery or Open (P011515)
    DESCRIPTION Refer to DTC P011511. Click here HINT: When DTC P011515 is stored, the ECM enters fail-safe mode. During fail-safe mode, the engine coolant temperature is estimated to be 80°C (176°F) by the ECM. Fail-safe mode continues until a pass condition is detected. DTC No. Detection Item ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Charging System: Freeze Frame Data
    FREEZE FRAME DATA DESCRIPTION The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was moving or stationary, whether the engine was warmed up or not, whethe ...

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

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

    © 2026 Copyright www.lexusrx.net
    0.0091