The TCS system sensors are connected to the ABS(Anti-lock Braking System) they monitor the speed of each of the wheels. When you see the Light on and it stays on, it could be a damaged or malfunctioning wheel speed sensors which can happen from corrosion(all the salt and gravel used in our harsh winters).Click to see full answer. Beside this, what does the TCS light mean on a 2003 Honda Odyssey? Traction Control System Also, what does it mean when your TCS light comes on? When the TCS Light is on, it means that the traction control system is not working and it will be shut off completely. This will make your wheels spin freely on acceleration or slippery surfaces and if you do not know it, it can cause serious accidents. Additionally, why does my engine and TCS light come on? TCS is traction control system. The TCS light comes on when the brake switch is defective,or out of alignment or the wheel speed sensor on the wheel is defective or the TCS modulator is defective. The latter two problem should throw some ODB II code.Why is the TCS light on 2003 Honda Accord?tcs – traction control system. If it’s on constantly then there is an issue with the system that you will to have fixed. Sometimes if the car loses traction the TCS light will flash to let you know the system is kicking in to control the car.