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Q: Traction Control System light always on

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It's already been a week that the TCS light of my car keeps coming on always, even when I try to switch it off. I've experienced few times, especially when the road is wet or when I come to a complete stop, and when I slowly accelerate it, that the wheels spin and sometimes the car sways during turning. I had the car checked and scanned and the mechanic suggested to replace the brake fluid master cylinder because there was a leak according to him. But I can't see any leak outside the cylinder. Is this leak why the TCS light is on? My car has 233458 miles.
My car has an automatic transmission.

Hi, thanks for writing in. Your car is equipped with wheel speed sensors at each of the four wheels which monitor wheel speed while relaying this information constantly to the ABS and traction control system which are controlled by the car’s ECU. When the ECU senses an abnormal speed given specific conditions, it engages the ABS or traction control as needed to control the vehicle properly and safely. Occasionally, these sensors can fail or become faulty working intermittently sending inaccurate signals to the ECU. When this happens, you may experience the symptoms you have described. The ABS or traction control system may be inadvertently activated by these false or inaccurate signals. If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this service light for you, and make or suggest any repairs as needed.

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