Dtc U0073 Control Module Communication Bus Off

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

DESCRIPTION

INSPECTION PROCEDURE

CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED

RECONFIRM DTC

REPAIR OR REPLACE HARNESS OR CONNECTOR

RECONFIRM DTC

DTC U0073 Control Module Communication Bus OFF

DTC U0142 Lost Communication with Main Body ECU


DESCRIPTION

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

DTC No.
DTC Detection Condition
Trouble Area
U0073
When any of the following is detected:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, after the output of data from the skid control ECU (brake actuator assembly) is completed, the sending continues for 5 seconds or more.
  2. The condition that bus OFF state occurs once or more within 0.1 seconds occurs 10 times in succession. (Sent signals cannot be received.)
CAN communication system
U0142
No communication with main body ECU
CAN communication system
Main body ECU

INSPECTION PROCEDURE

1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

  1. Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC (YARIS_NCP93 RM000000XHS0AMX.html).

    ABS/VSC/TRAC
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    EFI Communication Open
    		EFI communication open detection / Normal or Error
    		Normal: Normal
    Error: Momentary interruption
    		-
    Body ECU Communication Open
    		Body ECU open detection / Normal or Error
    		Normal: Normal
    Error: Momentary interruption
    		-

Result
Result
Proceed to
There is a constant open circuit
A
There are no momentary interruptions
B
There are momentary interruptions
C
HINT:
Perform the above inspection before removing the sensor and connector.


B
Go to step 3

C
Go to step 4
A


2.CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED

  1. Turn the ignition switch off.

  1. Check if each sensor or ECM connector is securely connected.

    OK:
    Each connector is securely connected.


NG
CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY
OK


3.RECONFIRM DTC

  1. Turn the ignition switch off.

  1. Record the output DTCs (for ABS, VSC, and CAN communication) (YARIS_NCP93 RM000000XHV0CPX.html).

    HINT:
    If the CAN communication system DTC and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for ABS) 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 CIRCUIT INDICATED BY OUTPUT DTC (YARIS_NCP93 RM000000XHU08XX.html)

C
CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (YARIS_NCP93 RM000000XHS0AMX.html)
A

CHECK CAN COMMUNICATION SYSTEM (YARIS_NCP93 RM000001RSO05UX.html)

4.REPAIR OR REPLACE HARNESS OR CONNECTOR

  1. Turn the ignition switch off.

  1. Repair or replace the harness or connector.

  1. Check for any momentary interruption between the skid control ECU (brake actuator assembly) and each sensor or ECM (YARIS_NCP93 RM000000XHS0AMX.html).

  1. Check that there is no momentary interruption.


NEXT


5.RECONFIRM DTC

  1. Turn the ignition switch off.

  1. Clear the DTC (YARIS_NCP93 RM000000XHV0CPX.html).

  1. Start the engine.

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

  1. Check that no CAN communication system DTC is output (YARIS_NCP93 RM000001RSW02LX.html).

  1. If ABS and VSC DTCs are output, record them.

Result
Result
Proceed to
DTC is not output
A
DTC is output (relating to ABS and/or VSC system)
B
DTC is output (relating to CAN communication system)
C
HINT:
The CAN communication system must be normal when repairing each sensor DTC (for ABS and VSC).


B
REPAIR CIRCUIT INDICATED BY OUTPUT DTC (YARIS_NCP93 RM000000XHU08XX.html)

C
CHECK CAN COMMUNICATION SYSTEM (YARIS_NCP93 RM000001RSO05UX.html)
A

END