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Home >> Saab >> 1995 >> 9000 CSE V6-2962cc 3.0L DOHC (B308) >> Repair and Diagnosis >> Brakes and Traction Control >> Antilock Brakes / Traction Control Systems >> Description and Operation >> Traction Control System >> Traction Control System V6

Traction Control System V6







The Traction Control System (TCS) Consists Of The Following Components:





- TCS control module
- Throttle body with direct current motor and position sensor for the TCS throttle
- TCS function lamp
- Warning lamp TCS OFF
- Switch ON/OFF





- The TCS helps to prevent uncontrolled wheel spin during both fast acceleration and on slippery road surfaces.
- The system is based on the double throttle principal.
- This principal is called the Twin-Throttle System (TTS).
- This traction system controls the torque of the engine by regulation of the throttle butterfly in the extra throttle body which forms part of the system.
- The extra TCS throttle body is mounted beside the ordinary wire-operated throttle body. When the car is in motion, the TCS throttle follows the ordinary throttle and is controlled by the TCS control module.
- As soon as maximum permitted wheelspin is exceeded, the TCS throttle opening angle is decreased in comparison to that of the throttle, at which point the engine torque is reduced until the wheelspin ceases.
- The most important information to the control module comes from the four wheel sensors via the Antilock Brake System (ABS) control module, but the TCS has no influence on the braking system. In order to compensate for normal changes in the diameter of the wheels, the system is adaptive to tire wear etc.
- "Mini Spare" spare wheels can be used with the TCS function retained.





Permitted Spin
- When starting on a slippery surface, the TCS allows a maximum wheelspin of 3 km/h. The upper limit for permitted wheelspin then decreases successively to approx. 1.5 km/h at 35 km/h, which is equivalent to a wheel spin of approx. 4.5%.
- Permitted wheelspin is then constant up to 100 km/h.
- Over 100 km/h the permitted wheelspin increases again and reaches approximately 3.5 km/h at 200 km/h, equivalent to a wheel spin of approximately 1.8%.
- At speeds over 200 km/h permitted wheelspin is again constant.





Control Of Throttle Function
- To control and synchronize the TCS throttle in relation to the ordinary throttle, a special control program is incorporated in the control module. The control covers calibration of the throttle butterfly fully open and fully closed positions, function and strength of the spring that returns the throttle butterfly to the fully open position and that the throttle butterfly moves friction-free.
- Further information on the control module's calibration of the throttle butterfly position can be found under "Control module".





Input Signals To The Control Module
- Switch, ON/OFF (pin 1)
- Engine speed signal (pin 6)
- Speed signal, FR (pin 7)
- Speed signal, RR (pin 8)
- Speed signal, RL (pin 24)
- Speed signal, FL (pin 25)
- Position signal, main throttle butterfly (pin 11)
- Position sensor, Traction Control System (TCS) throttle butterfly (pin 27)
- Diagnostics lead K (pin 9)*
- Brake light switch (pin 23)
- Voltage from +15 (pin 28)
- Voltage from +30 (pin 32)
- Ground (pins 13 and 30)
* also output signal





Output Signals From The Control Module
- Position sensor, TCS throttle butterfly (pin 3)
- Position sensor, TCS throttle butterfly (pin 20)
- Disconnection, cruise control (pin 5)
- Disconnection, full-load enrichment system (pin 21)
- TCS function lamp (pin 12)
- TCS OFF warning lamp (pin 26)
- Diagnostics, K lead (pin 9)*
- TCS throttle butterfly actuator motor (pin 18)
- TCS throttle butterfly actuator motor (pin 35)
* also input signal
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