Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Control Module Communication Bus Off (U0073,U0100,U0101,U0126,U0129,U0142,U0155)

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Exterior / Lighting (ext) / Lighting System (w/ Automatic Headlight Beam Level Control System) / Control Module Communication Bus Off (U0073,U0100,U0101,U0126,U0129,U0142,U0155)

DESCRIPTION

These DTCs are stored if a CAN communication malfunction occurs between the No. 1 headlight ECU sub-assembly LH and other ECUs.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

DTC Output from

U0073

Control Module Communication Bus Off

The No. 1 headlight ECU sub-assembly LH does not send/receive data.

CAN communication system

No. 1 headlight ECU sub-assembly LH

U0100

Lost Communication With ECM/PCM "A"

The No. 1 headlight ECU sub-assembly LH does not receive data from the ECM for approximately 10 seconds or more.
  • CAN communication system
  • ECM

No. 1 headlight ECU sub-assembly LH

U0101

Lost Communication with TCM

The No. 1 headlight ECU sub-assembly LH does not receive data from the ECM for approximately 10 seconds or more.
  • CAN communication system
  • ECM

No. 1 headlight ECU sub-assembly LH

U0126

Lost Communication with Steering Angle Sensor Module

The No. 1 headlight ECU sub-assembly LH does not receive data from the steering sensor for approximately 5 seconds or more.
  • CAN communication system
  • Steering sensor

No. 1 headlight ECU sub-assembly LH

U0129

Lost Communication with Brake System Control Module

The No. 1 headlight ECU sub-assembly LH does not receive data from the skid control ECU (brake actuator assembly) for approximately 5 seconds or more.
  • CAN communication system
  • Skid control ECU (brake actuator assembly)

No. 1 headlight ECU sub-assembly LH

U0142

Lost Communication with Body Control Module "B"

The No. 1 headlight ECU sub-assembly LH does not receive data from the main body ECU (multiplex network body ECU) for approximately 10 seconds or more.
  • CAN communication system
  • Main body ECU (multiplex network body ECU)

No. 1 headlight ECU sub-assembly LH

U0155

Lost Communication with Instrument Panel Cluster (IPC) Control Module

The No. 1 headlight ECU sub-assembly LH does not receive data from the combination meter assembly for approximately 30 seconds or more.
  • CAN communication system
  • Combination meter assembly

No. 1 headlight ECU sub-assembly LH

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) Wait 35 seconds or more.

(d) Turn the Techstream on.

(e) Enter the following menus: Body Electrical / AFS / Trouble Codes.

(f) Check for DTCs.

Body Electrical > AFS > Trouble Codes

OK:

DTCs are not output.

OK

USE SIMULATION METHOD TO CHECK

NG

GO TO CAN COMMUNICATION SYSTEM

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) Wait 35 seconds or more.

(d) Turn the Techstream on.

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

(f) Check for DTCs.

Body Electrical > HL AutoLeveling > Trouble Codes

OK:

DTCs are not output.

OK

USE SIMULATION METHOD TO CHECK

NG

GO TO CAN COMMUNICATION SYSTEM

    Left Headlight ECU Variation Error (B2456)
    DESCRIPTION This DTC is stored if the No. 1 headlight ECU sub-assembly LH for another destination is installed. DTC No. Detection Item DTC Detection Condition Trouble Area DTC Output from ...

    Lost Communication With ECM/PCM "A" (U0100,...,U1126)
    DESCRIPTION These DTCs are stored if a CAN communication malfunction occurs between the main body ECU (multiplex network body ECU) and other ECUs. DTC No. Detection Item DTC Detection Condition ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Sfi System: Registration
    REGISTRATION CAUTION / NOTICE / HINT PROCEDURE 1. VIN (VEHICLE IDENTIFICATION NUMBER) NOTICE: The Vehicle Identification Number (VIN) must be written to a replacement ECM. HINT: The VIN is a 17-digit alphanumeric vehicle identification number. The Techstream is required to register the VIN. (a) DESC ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Power Steering System: Vehicle Speed Signal (C1541)
    DESCRIPTION The power steering ECU assembly receives vehicle speed signals from the skid control ECU (brake actuator assembly) via CAN communication. The ECU provides appropriate assist force in accordance with the vehicle speed based on the signals. DTC No. Detection Item DTC Detection Condi ...

    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