Astra F
|
General Information for Repairs, TC (Traction Control) The TC (Traction Control) prevents slipping of the driving wheels - in particular on slippery roads due to rain, snow or ice. TC is available only in conjunction with ABS. The engine output or the engine torque is automatically controlled so that optimal driving stability and traction are constantly assured within the physical limits. The TC telltale flashes when the TC is engaged. A loss of engine power during the course of control can also be identified by the fact that the engine no longer reacts to the actuation of the throttle valve. The TC is automatically ready for operation after starting the engine. During the journey the system monitors itself constantly. If the TC telltale does not extinguish in a few seconds after switching on the ignition or illuminates permanently during the journey, then there is a fault in the TC. The vehicle can be used in the normal manner without any limitation. Excessive acceleration can, however, cause the driving wheels to slip. When driving with snow chains in deep snow or when "burrowing" out of soft ground, it is advisable to turn off the TC at the switch on the centre console. The system is switched on again by operating the TC switch or automatically when the ignition is switched on.
General Information for Repairs, TC (Continued) During operations on the TC, the following must be noted:
- Check vacuum and water connections check for leaks. - Observe proper seating of battery connections. - Never remove or connect the wiring harness multiple plug from/to the TC control unit and TC throttle body with the ignition switched on. - The stops on the TC throttle body must not be altered. If the stops are altered, the TC throttle body must be replaced. - After operations which involve the TC, it must be checked. The checking plan is contained in the brochure "TC Checking Procedures". - When carrying out electrical welding, the plug must be removed from the electronic control unit. - During painting work the ABS-Control unit may for a short time be subjected to 95 ° C and for a longer period - ca. 2 Hours - with a max. of 85 ° C.
After all operations on the TC, a function test is to be carried out. This means that the TC telltale must illuminate briefly and thereafter extinguish after the ignition has been switched on.
General Information for Repairs, TC (Continued) The information concerning the speed of the wheels is one of the most important input signals for the TC. Used tyres have a smaller diameter than tyres with full tread and therefore a higher wheel speed. If there are different types of tyres on the vehicle, this can lead to incorrect operation of the TC since different information on speeds are given to the control unit when the tyres have different diameters. To prevent this effect, automatic adjustment of tyre sizes is carried out in the control unit; this means that different diameters of tyres are recognised and the speed information corrected accordingly. As this adjustment is carried out only in certain driving situations and furthermore requires a certain amount of time, it can happen that the TC engages incorrectly immediately after tyres have been changed (e.g. when worn rear tyres are replaced with new ones). Completely incorrect tyres pressures on individual tyres can have the same effect. With problems of this kind one can attain quick adjustment of tyres as follows:
- Make sure that all tyres have correct pressures - Accelerate vehicle to a speed of 100-120 km/h/62-74 mph - Finally allow the vehicle to roll out straight ahead without depressing accelerator and brakes until it is travelling under 70 km/h/ 43 mph.
This operation is carried out five times after which complete adjustment of tyres is guaranteed.
|
