Dtc U0073 Control Module Communication Bus Off

Brake. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35
Brake Control. Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35

DESCRIPTION

WIRING DIAGRAM

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 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 receives signals from the ECM, steering angle sensor, and yaw rate and deceleration sensor via the CAN communication system.

DTC Code
DTC Detection Condition
Trouble Area
U0073
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 signals cannot be sent 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 deceleration 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 deceleration sensor and steering angle sensor occurs more than once within 5 seconds.
CAN communication system
U0100
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
(Skid control ECU to ECM)
U0123
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 deceleration sensor)
U0124
Either of the following is detected:
  1. When the IG1 terminal voltage is between 10 and 17.4 V, data from the deceleration 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 deceleration sensor cannot be received occurs once or more within 5 seconds.
CAN communication system
(Skid control ECU to yaw rate and deceleration sensor)
U0126
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)

WIRING DIAGRAM


Toyota Rav4. Aca30, 33, 38 Gsa33 Zsa30, 35.Brake Control.Anti-Lock Brake System. Dtc U0073 Control Module Communication Bus Off


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 the DTC (RAV4_ACA30 RM000000XHS04QX.html).

    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 angle sensor open detection / ERROR or NORMAL
    		ERROR: Momentary interruption
    NORMAL: Normal
    		-
    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 system and/or CAN communication system) (RAV4_ACA30 RM000000XHU09OX.html for ABS and VSC system, or RAV4_ACA30 RM000001W16007X.html for CAN communication system).

    HINT:
    If CAN communication system DTCs and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for ABS and/or VSC system) after the CAN communication system returns to normal.

    Result:

    Result
    		Proceed to
    DTC is not output.
    		A
    DTC is output.
    		ABS and/or VSC system DTC
    		B
    CAN communication system DTC
    		C


B
REPAIR CIRCUIT INDICATED BY OUTPUT DTC (RAV4_ACA30 RM000000XHU09OX.html)

C
INSPECT CAN COMMUNICATION SYSTEM (RAV4_ACA30 RM000001W16007X.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (RAV4_ACA30 RM00000135201PX.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 and each sensor or ECM (RAV4_ACA30 RM000000XHS04QX.html).

  1. Check that there are no momentary interruptions.


NEXT


5.RECONFIRM DTC

  1. Turn the ignition switch off.

  1. Clear the DTCs (RAV4_ACA30 RM000000ONJ02VX.html).

  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 that no CAN communication system DTC is output (RAV4_ACA30 RM000001W16007X.html).

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

    Result:

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


B
REPAIR CIRCUIT INDICATED BY OUTPUT DTC (RAV4_ACA30 RM000000XHU09OX.html)

C
INSPECT CAN COMMUNICATION SYSTEM (RAV4_ACA30 RM000001W16007X.html)
A

END