Why Does the Traction Control System Light (TCS Light) Come On?

What does the TCS light on the instrument panel mean? Why does the TCS light come on? To answer these questions, let’s first note that TCS stands for “Traction Control System,” meaning the ”Traction Control System”, and that this system is responsible for maintaining the vehicle’s proper road grip, especially in slippery road conditions. So, are you wondering why the traction control system light comes on? The TCS warning shows up in these situations:

The TCS light flashes as soon as the vehicle starts accelerating.
The TCS light is on with “OFF” written underneath it.
The TCS light stays on continuously
The TCS light keeps flashing continuously

Why the TCS Light Comes On

1) The TCS Light Flashes as Soon as the Vehicle Starts Accelerating

If you’re driving on slippery surfaces, it’s completely normal for the TCS light to flash while your wheels keep spinning as you accelerate. However, under normal road conditions — meaning the road isn’t slippery — if the TCS light flashes while the vehicle is slowing down and engine power drops significantly, the vehicle’s ABS sensor may be faulty. In other words, your vehicle isn’t actually slipping, but the ABS sensors are detecting it as if it were. In this case, check the codes coming from the ABS control unit to see whether the sensor is working.

2) The TCS Light Is On with “OFF” Written Underneath It

If you see a flashing TCS light with the word “OFF” continuously showing underneath it, your vehicle’s traction control system may have been disabled. Simply put, this means TCS is turned off.

What Does It Mean When the Traction Control System Is Off?

If the traction control system is off, engine power will not be adjusted in risky, slippery road conditions, and the risk of the wheels spinning excessively or the vehicle exceeding a safe speed on slippery roads will also increase.

If you’ve tried turning it off and back on and that didn’t fix anything, the problem may be in the mechanism itself.

How Do You Turn the Traction Control System On?

You can easily turn the traction control system on and off with a button inside your car. If you can’t find the button, check your owner’s manual to find out where it is.

how to turn on the traction control system

3) The TCS Light Stays On Continuously

If the TCS light stays on continuously, it means something is going on with your traction control system. Usually the ABS light joins this warning too. That is, both the ABS and TCS lights stay on continuously. The solution is to read the codes from the ABS control unit and see what they say. You can also have your mechanic take a look.

To read the ABS’s trouble codes, you need an onboard diagnostic scanner (OBD2). After plugging it into the OBD port located under the dashboard, some OBD2 scanners can immediately connect to a mobile app to display the information. (Image above)

4) The TCS Light Keeps Flashing Continuously

If both the TCS and ABS lights are on, there may be a problem in the traction control system, with a corresponding fault code in the ABS braking system.

When this happens, the braking system loses its anti-lock feature, causing the wheel to lock up when brake pressure is applied. As a result, the car may slow down, but this is very dangerous and hard to drive.

What Faults Might the TCS Light Be Indicating

5 Common Causes of the TCS Light on the Dashboard:

There may be a fault in the ABS sensor.
There may be a steering angle sensor fault.
There may be a problem in the wiring going to the ABS sensors.
There may be a problem with the tone ring/ABS ring.
Water may be getting into the ABS sensor connectors.
There may be a fault in the ABS control unit.

Since the braking system and the traction control system are closely related and use the same hardware, most faults are actually related to the anti-lock braking system (ABS). Often, the warning we assume is a TCS fault actually points to an ABS system fault.

Wheel Speed Sensors

The TCS system detects wheel slip using data from the ABS sensors, which measure each wheel’s speed individually.

Engine Torque Cut

When slip is detected, the system tries to restore wheel grip by temporarily reducing engine torque.

Sign of a Persistent Fault

If the TCS light stays on continuously, this usually indicates a sensor fault, and the system may be fully disabled.

Driving with the TCS Light On

Since traction control is extremely critical for driving, the TCS light coming on should not be ignored. A TCS fault can prevent your wheels from gripping the road properly and can cause you to lose control of the vehicle on slippery roads, which damages your tires and engine performance and increases the risk of an accident. If you keep driving for a long time with the TCS light on, TCS- or ABS-related issues can cause the brakes to fail. For this reason, if the TCS and ABS lights come on, you should have your mechanic check it right away.

Is It Safe to Drive with the TCS Light On?

The TCS light comes on to warn that the vehicle’s safety is being compromised while the vehicle is still operating normally. While the TCS light is on, the vehicle’s ability to detect changes in traction is impaired.

In the worst-case scenario, the vehicle will no longer have a working traction control system. In this case, engine power won’t be adjusted, and the risk of the wheels spinning excessively or exceeding a safe speed on slippery roads will also increase.

Also, a bright TCS light can be a sign of an engine fault. You should have it checked as soon as possible.