Few things are as alarming as when a warning light appears in your dash as you accelerate. And in this case, it turns out to be the traction control light.
Like an overbearing parent, it restricts your vehicle’s fun while providing little explanation for its harsh judgement. Typically harmless, it could signal something serious. Let’s look at some of the most common reasons the traction control light comes on while you’re accelerating.
What is Traction Control?
Traction control uses wheel speed sensors to detect when one driven wheel is spinning faster than the other wheels. In this condition, the ABS activates on the slipping wheel to slow its speed. Once the slipping wheel slows down, it is able to grip the road again and the brake on that corner of the vehicle is released.
Sometimes, the ECU will also reduce engine torque in addition to using the ABS system to apply the brakes.
Many vehicles also have a stability control system. Stability control leverages the use of ABS in a similar way. This system works to keep the vehicle pointed in the direction you want to go, even if the road is slippery and you start sliding. These two systems work together, so a malfunction in one will likely affect the other.
A rolling tire has more grip than a sliding tire. If the front tires are sliding, your ability to steer will be hindered. In extreme cases, you may not even be able to steer at all! In this case, your vehicle will follow the direction you were headed before you started to slide.
When one or more tires lose lose grip and start spinning, the traction control system will detect this problem and then act accordingly to correct the issue.
The traction control light (or TCS light) often flashes at the very moment wheel slip is detected and the system kicks in to correct the problem. This flashing is no cause for concern, but you should take note of the occurrence and drive a bit more carefully.
If there is a problem with the traction control system that hinders its ability to work effectively, the traction control light will remain illuminated indefinitely.
Related: What is Ford AdvanceTrac?
Top 9 Reasons the Traction Control Light is On
If the traction control light does come on, it will usually do so while you’re accelerating. Do not panic when this happens because you need to focus on stabilizing the steering wheel as best as possible.
The traction control system is not going to assist you like it did before, so you need to be extra careful here. Below are the most common causes of a traction control light coming on when you are accelerating.
See Also: What Does “Check VSA System” Mean?
1) Bad Wheel Speed Sensors
Wheel speed sensors are connected to your traction control system and engine control unit. These sensors are responsible for detecting the speed in which your wheels are rotating. Each wheel has its own sensor.
If the rotation speed of any wheel changes unexpectedly or unusually as you’re accelerating, the wheel speed sensors will detect the change and notify the traction control system.
But if the wheel speed sensors are not working, the traction control system will not be notified. Then your vehicle will lose traction, causing the traction control light to come on.
A bad wheel speed sensor may also trigger your ABS or brake light to come on.
2) Bad Steering Angle Sensor
The steering angle sensor calculates the angle of the steering wheel and the rate in which it is being turned. The sensor is positioned in the steering column so that it can track the angle and rate precisely.
This sensor is typically used by the stability control system to detect the direction the driver intends to go. If the sensor goes bad, you can expect the traction control light to come on.
You may notice stability control issues with a bad clock spring.
3) Bad Road Conditions
If the road conditions are too severe, your traction control system may not be able to handle it. For instance, if you live in a location with a lot of snow and ice on the ground, then the roads are going to be difficult to maintain traction on.
If the traction gets to be too difficult, then your traction control light may illuminate on the dashboard. There isn’t much you can do other than getting your vehicle to a better area with safer roads.
Consider buying winter tires if you don’t have them installed already. Winter tires are much better suited for slick road conditions than your standard all season tire. If you have the space, you can buy a second set of wheels and swap them over whenever you need to.
4) Low Tire Pressure
Driving with tires that are underinflated reduces their traction and contact with the road surface, which can activate the traction control system and cause the warning light to come on when accelerating.
Low tire pressure allows more tire flex and distortion as you press down on the gas pedal. This excessive flexing triggers the vehicle’s computer to detect a loss of traction. The traction control kicks in to try to prevent tire slippage, while simultaneously turning on the traction control warning light on the dashboard.
Continuing to drive on significantly underinflated tires can be dangerous due to the loss of vehicle control and can also lead to overheating and blowouts. It causes uneven and accelerated tire wear as well. This degrades handling and traction capabilities even after refilling them to the proper inflation levels.
5) Bad Steering Rack
The steering rack is attached to your steering wheel and is an important part of the power steering system. It receives the high-pressure hydraulic fluid that is necessary for making it easy to turn the steering wheel.
Part of having good traction is having smooth steering that is easy to control. So, if you have a bad steering rack, it will be harder to steer your vehicle on a rough road. This will cause your traction control light to possibly come on.
6) Programming Issues
There may be a circumstance where the traction control system must be reprogrammed because it is having issues with its current programming. Sometimes these programming errors can happen as time goes on. Other times they are a result of a manufacturer defect or oversight.
If the traction control system ever has this problem, the traction control light will come on. Only a certified mechanic who specializes in your make and model vehicle will be able to fix the programming issues.
7) Limp Mode
When a vehicle enters limp mode, the dashboard usually lights up like a Christmas tree. One of these lights will likely be the traction control light.
Limp mode keeps the powertrain safe while still allowing the driver to “limp” his vehicle to a mechanic for a repair. This prevents the driver from being stranded and needing a tow.
8) Bad Wheel Bearing
Faulty wheel bearings can also trigger the traction control light to activate when pressing down on the gas pedal. Wheel bearings allow the wheels to spin smoothly and quietly. But over time with wear, they can become loose or damaged. This degradation eventually causes noticeable vibration, noise, and handling issues.
When accelerating with compromised wheel bearings, vibration through the chassis increases significantly. This throws off the wheel speed sensors that constantly relay rotational inputs to the vehicle computer. The abnormal signals from the failing bearings trick the computer into thinking wheel traction is lost, prompting traction control engagement.
9) Manual Override
Many vehicles have a button you can press to disable the traction control or stability control systems. You may wish to disable traction control if you are stuck in deep snow or mud. In some cases, a little wheel slip may actually help free you.
Sports cars come with the ability to disable traction and stability control systems to give the driver more control over the vehicle’s handling dynamics. Psst… it may also allow you to do a burnout, even in an automatic.
Even if you disable traction control manually, it will likely turn itself back on when you restart the vehicle.
Every traction and stability control system is different. Likewise, so is the procedure to disable them. Consult your owner’s manual for your specific vehicle’s procedure.
Can You Drive With the Traction Control Light On?
If the only light illuminated on the dash is the traction control light, chances are it’s fairly safe to drive. If it’s wet or slippery outside, you’ll want to take extra care when accelerating or taking turns.
In these conditions, the vehicle may behave unpredictably. If you’re not used to the way a sliding car feels, it can be a very scary experience.
Remember, a rolling tire has more grip than a slipping tire. Accelerate, steer, and brake smoothly so you don’t upset the balance of the vehicle. Look as far down the road as you can, and look in the direction you want to go. Remember to maintain a safe following distance.
Diagnosing the Root Cause
Your traction control light came on, but how do you determine the culprit? With some basic diagnostic tests, you may be able to get clues and narrow down the problem before taking your car in to the repair shop.
1) Inspect the Tires
Start by visually inspecting all four tires carefully. Look for significant tread wear or uneven wear patterns. Feel for any cuts, gouges, or bulges in the sidewalls. Then use a reliable tire pressure gauge to check if all tires meet the automaker’s inflation specifications (usually listed in the driver side door jamb).
Driving on under-inflated, damaged, or excessively worn tires is a very common reason for traction control activation.
Listen for any abnormal noises coming from the wheel wells as your accelerate gently in a clear area. Growling and loud humming may indicate a stuck or damaged wheel bearing. Also feel for any vibrations coming through the steering wheel or seats at various speeds.
Vibration felt mainly at high speeds can point to out of balance wheels or bad wheel bearings.
3) Scan for Trouble Codes
Finally, use an OBD2 scanner connected to the diagnostic port underneath the dash to check for any stored codes.
While the check engine light may not directly correlate to the traction control issue, stored codes can reveal transmission, engine misfire, or ABS wheel sensor faults that are contributing to activation of the traction control system while driving.
When to Get Professional Help
While some traction control light issues can be simple fixes, the illuminated warning light shouldn’t be ignored, especially when it occurs alongside other dashboard warning symbols or changes in vehicle performance.
It’s a good idea to seek professional service in these situations:
- The traction control light comes on simultaneously with the Check Engine light or other warning lights like ABS, temperature, or oil pressure. This indicates multiple sensor faults are detected and likely a complex electrical/mechanical issue.
- You notice burning smells coming from the wheels, white smoke from the hood, or overheating engine temperatures when the traction control activates. These signs point to severe friction and components wearing prematurely.
- Loss of acceleration power occurs and the vehicle feels sluggish or weak whenever pressing the gas pedal. The traction control system may be reducing engine throttle despite no visible wheel slippage.
- You recently had body work done like lifting the vehicle or replacing transmission components which may impact computer guidance of traction control responses.
- You observe leaking brake fluid or damaged hydraulic brake lines which interconnect with the traction control system.