BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: U0073,U0100,U0123,U0124,U0126; Control Module Communication Bus OFF; 2017 MY Sienna [08/2016

Last Modified: 04-05-2023	6.11:8.1.0	Doc ID: RM1000000010U3R
Model Year Start: 2017	Model: Sienna	Prod Date Range: [08/2016 - 11/2017]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: U0073,U0100,U0123,U0124,U0126; Control Module Communication Bus OFF; 2017 MY Sienna [08/2016 - 11/2017]

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, yaw rate and acceleration sensor (w/ VDIM) and yaw rate and acceleration sensor (airbag sensor assembly) (w/o VDIM) via CAN communication.

DTC Code	DTC Detection Condition	Trouble Area
U0073	Any of the following is detected: 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. The condition that bus OFF state occurs once or more within 0.1 seconds occurs 10 times in succession. (Sent signals cannot be received.) 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. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession. 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 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: 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. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession. 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	Either of the following is detected: 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. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession. 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	Either of the following is detected: 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. When the IG1 terminal voltage is between 10 and 17.4 V, the following occurs 10 times in succession. 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

PROCEDURE

1.	CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC (See page ).

ABS/VSC/TRAC

Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
EFI Communication Open	ECM 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	-
Deceleration Open	Acceleration 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.

GO TO STEP 3

GO TO STEP 4

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

(a) Turn the ignition switch off.

(b) Check if each sensor or ECM connector is securely connected.

OK:

Each connector is securely connected.

CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY

3.	RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Record the output DTCs (for ABS, VSC system and/or CAN communication system) (See page for ABS and VSC system, or 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 (ABS and/or VSC system DTC) is output	B
DTC (CAN communication system DTC) is output	C

USE SIMULATION METHOD TO CHECK

REPAIR CIRCUIT INDICATED BY OUTPUT DTC

CHECK CAN COMMUNICATION SYSTEM

4.	REPAIR OR REPLACE HARNESS OR CONNECTOR

(a) Turn the ignition switch off.

(b) Repair or replace the harness or connector.

(d) Check that there are no momentary interruptions.

5.	RECONFIRM DTC

(a) Turn the ignition switch off.

(b) Clear the DTCs (See page ).

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

(e) Check that no CAN communication system DTC is output (See page ).

(f) If ABS and/or VSC system DTCs are output, record them.

Result

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

HINT:

The CAN communication system must be normal when performing troubleshooting for each sensor DTC (for ABS and/or VSC system).

END

REPAIR CIRCUIT INDICATED BY OUTPUT DTC

CHECK CAN COMMUNICATION SYSTEM