A-TRAC is an active traction control system that has been installed on some 4WD Toyota cars. It improves the traction of the vehicle when driving off-road and helps to regain the grip in case of wheel slip.
How it works
The speed of the wheels is analysed with the help of the ABS sensors. If one of the wheels starts slipping, the system slows the wheel down with the help of the ABS hydraulic unit and brakes. As a result, the torque on the opposite wheel increases. This allows the car to easily negotiate difficult off-road areas. The specific wheel is slowed down until traction is restored.
The system can be switched on and off when necessary by pressing a button on the centre console. A corresponding indicator lights up on the dashboard when it is activated.
Toyota models equipped with A-TRAC
Reasons for A-TRAC malfunction
- Failure of ABS sensors.
- Low brake fluid level.
- Abrasion of ABS sensor wires.