Traction Control System: Description

CAUTION: See ANTI-LOCK BRAKE SAFETY PRECAUTIONS article in GENERAL INFORMATION.

Saab 9000 Traction Control System (TCS) consists of TCS control module, Throttle body with direct current motor and position sensor for TCS throttle, TCS function light, TCS OFF warning light, and ON/OFF switch.

TCS helps to prevent uncontrolled wheel spin during both fast acceleration and on slippery road surfaces. System is based on double throttle principle, known as Twin-Throttle System (TTS). This traction system controls torque of engine by regulation of throttle valve in extra throttle body. Extra TCS throttle body is mounted next to conventional throttle body. When maximum permitted wheel spin is exceeded, TCS throttle opening angle is decreased in comparison to that of throttle, reducing engine torque until wheel spin stops.

Four wheel speed sensors provide wheel speed information to ABS control module. ABS control module supplies this wheel speed information to TCS control module. TCS has no effect on ABS system. To compensate for normal changes in diameter of tires, system is adaptive to changes such as tire wear. Mini spare tire and wheel can be used with TCS function retained.