Toyota Tundra Service Manual: Control Module Communication Bus "A" Off (U0073,U0123,U0129,U0155)

Toyota Tundra Service Manual / Brake / Brake Control / Dynamic Control Systems / Trailer Brake Control System / Control Module Communication Bus "A" Off (U0073,U0123,U0129,U0155)

DESCRIPTION

The trailer brake control ECU (brake control with bracket relay) receives signals from the skid control ECU (brake actuator assembly), yaw rate and acceleration sensor (airbag sensor assembly) and combination meter assembly via CAN communication.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

U0073

Control Module Communication Bus "A" Off

-

Bus off condition continues for 1 second or more

CAN communication system

U0123

Lost Communication with Yaw Rate Sensor Module

-

With a vehicle speed of 6 km/h (4 mph), the system is continuously unable to receive data from the yaw rate and acceleration sensor (airbag sensor assembly) for 1 second or more
  • CAN communication system
  • Trailer brake control ECU (Brake control with bracket relay)
  • Yaw rate and acceleration sensor (airbag sensor assembly)

U0129

Lost Communication with Brake System Control Module

-

The skid control ECU (brake actuator assembly) is continuously unable to receive data from the brake actuator assembly (skid control ECU) for 1 second or more.
  • CAN communication system
  • Trailer brake control ECU (Brake control with bracket relay)
  • Skid control ECU (Brake actuator assembly)

U0155

Lost Communication With Instrument Panel Cluster (IPC) Control Module

-

With a vehicle speed of 6 km/h (4 mph), the system is continuously unable to receive data from the combination meter assembly for 5 seconds or more
  • CAN communication system
  • Trailer brake control ECU (Brake control with bracket relay)
  • Combination meter assembly

PROCEDURE

1.

CHECK DTC

(a) Clear the DTCs.

Click here

(b) Turn the ignition switch off.

(c) Turn the ignition switch to ON.

(d) Check if the same DTC is output.

Click here

HINT:

If a CAN communication malfunction DTC and a related sensor malfunction DTC are output at the same time, the CAN communication malfunction must be repaired before troubleshooting the sensor malfunction DTC.

Result

Proceed to

CAN communication system DTCs are output.

A

DTCs are not output.

B
A

INSPECT CAN COMMUNICATION SYSTEM

B

USE SIMULATION METHOD TO CHECK

    Terminals Of Ecu

    Vehicle Stability Control System

    See More:

    Toyota Tundra Service Manual > Lin Communication System: P/W Master Switch Communication Stop (B1206)
    DESCRIPTION This DTC is stored when LIN communication between the power window regulator master switch assembly and main body ECU (multiplex network body ECU) stops for 10 seconds or more. DTC Code DTC Detection Condition Trouble Area B1206 No communication between the power window regulator master ...

    Toyota Tundra Owners Manual

    Toyota Tundra Service Manual

    © 2026 Copyright www.ttundra.com
    0.0118