System Description

SYSTEM DESCRIPTION

Trailer sway control reduces sway caused by the trailer's side to side oscillation. Trailer sway control function detects oscillation status using each sensor when trailer sway is occurring and improves vehicle stability by brake control and engine output control during driving.
Oscillation amount is calculated according to steering operation amount from steering angle sensor and brake operation amount from pressure sensor. By comparing this information with trailer sway amount that is calculated from yaw rate/side/decel G sensor and wheel sensor information, vehicle driving conditions (conditions of understeer or oversteer) are judged and trailer stability is improved by brake force control on all 4 wheels and engine output control of the towing vehicle.
Trailer sway control function can be switched to non-operational status (OFF) by operating VDC OFF switch. In this case, VDC OFF indicator lamp turns ON.
VDC warning lamp is blinking while trailer sway control function is in operation and indicates to the driver that the function is in operation.
Slight vibrations are felt on the brake pedal and the operation noises occur, when trailer sway control function operates. This is not a malfunction because it is caused by trailer sway control function that is normally operated.
CONSULT can be used to diagnose the system diagnosis.
Fail-safe function is adopted. When a malfunction occurs in VDC function, the control is suspended for VDC function, trailer sway control function and TCS function. The vehicle status becomes the same as models without VDC function, trailer sway control and TCS function. However, ABS function and EBD function are operated normally. Refer to Fail-safe .

SYSTEM DIAGRAM

Courtesy of NISSAN NORTH AMERICA, INC.

INPUT AND OUTPUT SIGNALS

Major signal transmission between each unit via communication lines is shown in the following table:

Component	Signal description
Yaw rate/side/decel G sensor	Mainly transmits the following signals to ABS actuator and electric unit (control unit) via communication line *1. Yaw rate signal Side G sensor signal Decel G sensor signal
ECM	Mainly transmits the following signals to ABS actuator and electric unit (control unit) via CAN communication. Accelerator pedal position signal Engine speed signal Mainly receives the following signal from ABS actuator and electric unit (control unit) via CAN communication. Target throttle position signal
TCM	Mainly transmits the following signal to ABS actuator and electric unit (control unit) via CAN communication. Shift position signal
Transfer control unit *2	Mainly transmits the following signal to ABS actuator and electric unit (control unit) via CAN communication. Current 4WD mode signal
Steering angle sensor	Mainly transmits the following signal to ABS actuator and electric unit (control unit) via CAN communication. Steering angle sensor signal
Combination meter	Mainly receives the following signals from ABS actuator and electric unit (control unit) via CAN communication. VDC warning lamp signal VDC OFF indicator lamp

*1: Communication line between yaw rate/side/decel G sensor and ABS actuator and electric unit (control unit)

*2: Models with 4WD system

OPERATION CHARACTERISTICS

Trailer sway control function prevents tow vehicle and trailer from oscillating.

During oscillation, brake force (brake fluid pressure) is applied on front wheel and rear wheel on the outer side of oscillation. Momentum directing towards the outer side of oscillation is generated. Trailer sway is reduced.

Courtesy of NISSAN NORTH AMERICA, INC.