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

for Preparation Click here


DESCRIPTION

The skid control ECU receives the signals from the ECM, steering angle sensor, and yaw rate and acceleration sensor via the CAN communication system.

DTC Code
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 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.)
  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 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 steering angle sensor occurs more than once within 5 seconds.
CAN communication system
U0100
When either of the following is detected:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, and the vehicle speed 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 15 km/h (9 mph) or more, data cannot be received to the ECM for 2 seconds or more.
CAN communication system
(Skid control ECU to ECM)
U0123
When either of the following is detected:
  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
(Skid control ECU to yaw rate and acceleration sensor)
U0124
When either of the following is detected:
  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
(Skid control ECU to yaw rate and acceleration sensor)
U0126
When either of the following is detected:
  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
(Skid control ECU to steering angle sensor)

INSPECTION PROCEDURE

1.CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

  1. Using the intelligent tester, check for any momentary interruption in the wire harness and connector corresponding to a DTC (Click here).

    ABS/VSC/TRC 
    Tester Display
    		Measurement Item/Range
    		Normal Condition
    		Diagnostic Note
    EFI Communication Open
    		EFI communication open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Yaw Rate Open
    		Yaw rate sensor open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    Steering Open
    		Steering sensor open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-

    Result:

    Result
    		Proceed to
    There are momentary interruptions
    		A
    There are no momentary interruptions
    		B
    There is a constant open circuit
    		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) (Click here).

    HINT:
    If the 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 output (relating to CAN communication system)
    		A
    DTC output (relating to ABS and/or VSC system)
    		B
    DTC not output
    		C



B
REPAIR CIRCUIT INDICATED BY OUTPUT DTC (Click here)

C
CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (Click here)
A

CHECK CAN COMMUNICATION SYSTEM (Click here)  

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 and each sensor or ECM (Click here).

  1. Check that there is no momentary interruption.


NEXT


5.RECONFIRM DTC

  1. Turn the ignition switch off.

  1. Clear the DTC (Click here).

  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 (Click here).

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

    Result:

    Result
    		Proceed to
    DTC output (relating to CAN communication system)
    		A
    DTC output (relating to ABS and/or VSC system)
    		B
    DTC not output
    		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 (Click here)

C
END
A

CHECK CAN COMMUNICATION SYSTEM (Click here)