Dtc U0073 Control Module Communication Bus Off


DESCRIPTION

INSPECTION PROCEDURE

RECONFIRM DTC

DTC U0073 Control Module Communication Bus OFF

DTC U0100 Lost Communication with ECM / PCM

DTC U0123 Lost Communication with Yaw Rate Sensor Module

DTC U0124 Lost Communication with Lateral Acceleration Sensor Module

DTC U0126 Lost Communication with Steering Angle Sensor Module


DESCRIPTION

The skid control ECU (brake actuator assembly) receives signals from the ECM, steering angle sensor (spiral cable sub-assembly) and yaw rate sensor assembly via the CAN communication system.

DTC Code
DTC Detection Condition
Trouble Area
U0073
One of the following conditions is met:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, after the output of data from the skid control ECU is completed, the sending operation continues for 5 seconds or more.
  2. The condition that the bus OFF state occurs once or more within 0.1 seconds occurs 10 times in succession (sent signals cannot be received).
  3. When the IG1 terminal voltage is between 10 and 17.4 V, a delay in receiving data from the yaw rate and acceleration sensor and the steering angle sensor continues for 1 second or more.
  4. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession.
    1. The condition that a delay in receiving data from the yaw rate and acceleration sensor and the steering angle sensor occurs more than once within 5 seconds.
CAN communication system
U0100
Either condition is met:
  1. When the IG1 terminal voltage is between 10 and 17.4 V and the vehicle speed is 15 km/h (9 mph) or more, data cannot be sent to the ECM for 2 seconds or more.
  2. When the IG1 terminal voltage is between 10 and 17.4 V and the vehicle speed is 15 km/h (9 mph) or more, data cannot be received from the ECM for 2 seconds or more.
CAN communication system
U0123
Either condition is met:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, data from the yaw rate sensor cannot be received for 1 second or more.
  2. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession.
    1. The condition that data from the yaw rate sensor cannot be received occurs once or more within 5 seconds.
CAN communication system
U0124
Either condition is met:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, data from the acceleration sensor cannot be received for 1 second or more.
  2. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession.
    1. The condition that data from the acceleration sensor cannot be received occurs once or more within 5 seconds.
CAN communication system
U0126
Either condition is met:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, data from the steering angle sensor cannot be received for 1 second or more.
  2. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession.
    1. The condition that data from the steering angle sensor cannot be received occurs once or more within 5 seconds.
CAN communication system

INSPECTION PROCEDURE

1.RECONFIRM DTC

  1. Clear the DTCs (Toyota Fortuner RM000000XHV0C7X.html).

  1. Turn the ignition switch off.

  1. Start the engine.

  1. Drive the vehicle at a speed of 15 km/h (9 mph) or more and turn the steering wheel to the right and left.

  1. Check for DTCs (Toyota Fortuner RM000000XHV0C7X.html).

    HINT:
    If a CAN communication system DTC and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for ABS and VSC) after the CAN communication system returns to normal.
    Result
    Result
    		Proceed to
    DTC (relating to CAN communication system) is output
    		A
    DTC (relating to ABS and/or VSC system) is output
    		B
    DTC is not output
    		C


B
REPAIR CIRCUITS INDICATED BY OUTPUT DTCS (Toyota Fortuner RM000000XHU08LX.html)

C
USE SIMULATION METHOD TO CHECK (Toyota Fortuner RM0000012Q9013X.html)
A

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING) (Toyota Fortuner RM000002VT000OX.html)