VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:U0073, U0100, U0124, U0126

DTC Code	DTC Name
U0073	Control Module Communication Bus OFF
U0100	Lost Communication with ECM
U0124	Lost Communication with Lateral Acceleration Sensor Module
U0126	Lost Communication with Steering Angle Sensor Module

DESCRIPTION

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

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U0073	Control Module Communication Bus OFF	When any of the following is detected: The condition that the bus OFF state occurs once or more within 0.1 seconds occurs 10 times in succession while the voltage at the IG1 terminal is between 10 and 17.4 V. (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 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 sensor and steering angle sensor occurs more than once within 5 seconds.	CAN communication system
U0100	Lost Communication with ECM	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
U0124	Lost Communication with Lateral Acceleration Sensor Module	When either of the following is detected: When the IG1 terminal voltage is between 10 and 17.4 V, and the vehicle speed is 7 km/h or more, 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
U0126	Lost Communication with Steering Angle Sensor Module	When 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

PROCEDURE

CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

Using the GTS, check for any momentary interruption in the wire harness and connector corresponding to a DTC.

Click here

Chassis > ABS/VSC/TRC > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
EFI Communication Open	ECM communication open detection	Normal or Error	Normal	Error: Momentary interruption
Yaw Rate Open	Yaw rate sensor open detection	Normal or Error	Normal	Error: Momentary interruption
Deceleration Open	Acceleration sensor open detection	Normal or Error	Normal	Error: Momentary interruption
Steering Open	Steering angle sensor open detection	Normal or Error	Normal	Error: Momentary interruption

Chassis > ABS/VSC/TRC > Data List

Tester Display
EFI Communication Open
Yaw Rate Open
Deceleration Open
Steering Open

Tech Tips

Perform the above inspection before removing the sensor and connector.

Result

Proceed to
There is a constant open circuit
There are no momentary interruptions
There are momentary interruptions

There are no momentary interruptions

GO TO STEP 3 Click here

There are momentary interruptions

REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

There is a constant open circuit

CHECK IF EACH SENSOR AND ECM CONNECTOR IS SECURELY CONNECTED

Turn the ignition switch off.

Check if each sensor or ECM connector is securely connected.

OK
Each connector is securely connected.

Result

Proceed to
OK
NG

CONNECT CONNECTOR TO EACH SENSOR OR ECM CORRECTLY

RECONFIRM DTC

Turn the ignition switch off.

Record the output DTCs (for VSC system and/or CAN communication system).

for VSC system: Click here

for CAN communication system for LHD: Click here

for CAN communication system for RHD: Click here

Chassis > ABS/VSC/TRC > Trouble Codes

Tech Tips

If the CAN communication system DTC and the relevant sensor DTCs are output simultaneously, troubleshoot the relevant sensor DTCs (for VSC system) after the CAN communication system returns to normal.

Result

Result	Proceed to
DTC (relating to CAN communication system) is output (for LHD)	A
DTC (relating to CAN communication system) is output (for RHD)	B
DTC (relating to VSC system) is output	C
DTC is not output	D

CHECK CAN COMMUNICATION SYSTEM Click here

REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

USE SIMULATION METHOD TO CHECK Click here

REPAIR OR REPLACE HARNESS OR CONNECTOR

Turn the ignition switch off.
Repair or replace the harness or connector.
Check for any momentary interruption between the skid control ECU (brake actuator assembly) and each sensor or ECM.

Click here

Check that there is no momentary interruption.

Result

Proceed to
NEXT

RECONFIRM DTC

Turn the ignition switch off.
Clear the DTCs.

Click here

Chassis > ABS/VSC/TRC > Clear DTCs
Start the engine.
Drive the vehicle at a speed of 15 km/h (9 mph) or more and turn the steering wheel to the right and left.
Check that no CAN communication system DTC is output.

for LHD: Click here

for RHD: Click here

If VSC system DTCs are output, record them.

Chassis > ABS/VSC/TRC > Trouble Codes

Tech Tips

The CAN communication system must be normal when repairing each sensor DTC (for VSC system).

Result

Result	Proceed to
DTC is not output	A
DTC is output (relating to VSC system)	B
DTC is output (relating to CAN communication system) (for LHD)	C
DTC is output (relating to CAN communication system) (for RHD)	D

END

REPAIR CIRCUIT INDICATED BY OUTPUT DTC Click here

CHECK CAN COMMUNICATION SYSTEM Click here