Traction Control (TC) is another crucial addition to modern vehicles that aims to keep them on the road and moving forward even on tricky surfaces. Traction control has evolved from the early days of antilock brakes into more advanced systems that make it easier to keep your tires biting on gravel, snow, or mud.
If you are keen, modern vehicles rarely spin wheels that much. This is because traction control algorithms work better at finding a way to send torque to the wheel with the best traction and stop a wheel that’s on black ice or suspended in the air from spinning fast and consuming all the torque.
How Does Traction Control Work?
Traction Control systems use wheel speed sensors to compare rotational speed in different tires. If one or two tires are spinning considerably fast than the rest, the TC module infers that the affected wheel is slipping.
The power train control module and ECU will then work together to remedy the situation and restore traction by:
- Braking the wheel that’s slipping and spinning faster so that torque goes to the slower wheel with more traction
- Use active torque vectoring to send power to the wheels that are not slipping
- Moderate throttle response when traction loss happens during acceleration to reduce torque at the wheels so that they can grip better
What Does the TC Light Mean?
Usually, the TC light should be off. This indicates that the system works perfectly, and you have nothing to worry about. If the TC light is on, the system is disabled, and the car’s computers are no longer intervening to give you the best traction on the road.
The traction control light is either an amber light with the words TC or an icon of a car with squiggly lines behind it. (The skid marks a vehicle will make when it loses traction and sways from side to side on the road.
Why is the Traction Control Off Light On?
Your traction control off light could pop up for a couple of reasons. Some are easy to fix in the settings menu, while others will need extra troubleshooting or a visit to the mechanic. Here are the top reasons that will bring the light on.
You Have Disabled Traction Control
All vehicles with traction control give you an option to disable it manually. This could be as simple as a Traction Control button somewhere on the dashboard or a menu in the infotainment system.
Hardcore offroaders often switch off traction control since it could be a bit intruding when trying to get unstuck from deep mud.
Racers and people who want to drift could also turn it off since it could interfere with your ability to do burnouts, drift, or launch your vehicle ideally.
Confirm that TC isn’t off by pressing the traction control button again or confirming it is still on in the settings menu.
If this doesn’t fix the problem and the TC light won’t go off, there’s a problem in the system.
Your Traction Control System is Working Actively
Some vehicles turn on the traction control light when your wheels lose traction, and the system kicks in to restore it. Chances are, the traction control light will be flashing as the wheels lose and regain traction as you drive.
This shouldn’t be a problem, especially if you are driving on a slippery surface and you can feel your wheels slipping and jerking as the vehicle tries to gain traction.
The light should go off when you are back on paved or dry surfaces where the tires have no trouble gripping.
If it persists, there is a problem with your traction control system.
There’s an Issue With Your Traction Control System
If you have a traction control light that won’t go off (or a specific ‘service traction control’ warning), you should start troubleshooting the system and find out what is wrong.
Some of the common problems that will throw this error include:
Faulty Wheel Speed Sensors
The traction control system uses wheel speed sensor readings to determine how fast your wheels are spinning.
If any of the wheel’s speed changes in an unusual way when driving or accelerating, the traction control system picks this up and compares it to other sensor outputs to determine if you are spinning and takes the necessary steps to restore traction.
No readings or garbled readings from a single sensor are enough to throw the entire system off. The TC module throws an error code that disables the system and lights up the Traction Control light on your dashboard as a fail-safe.
Some vehicles will report an exact error directing you to the faulty module, while others leave you in the dark, forcing you to bench test all your wheel speed sensors.
ProTip: Sometimes, dirt or mud can obscure your wheel speed sensors leading to errors. Keep your wheel wells clean and avoid painting over sensors to avoid such problems.
A Bad Steering Angle Sensor
A steering angle sensor sits on your steering column and helps calculate your steering input and determine the direction you want the car to go.
Vehicles with torque vectoring or brake assisted steering can feed this information to the traction control system, which uses it to control power to different wheels and influence how well your vehicle corners.
A fault in this sensor could also affect your traction control system and make the error light pop up.
You Have the Wrong Size Wheels
Your ECU estimates correct wheel speed by comparing a wheel’s revolutions per second and the vehicle’s reigning forward or backward speed.
The circumference of the tires is crucial in making this math accurate.
- Small diameter wheels will have to spin faster to maintain 50 MPH speeds
- Bigger diameter wheels can spin slower to hit the same 50 MPH speed
Your traction control module expects a specified RPM to speed ratio – a pre-programmed constant. Changing your wheels for one not recommended in your user manual throws this reading off.
- When buying new tires, stick to the dimensions given in your user manual or on the plac on the driver’s door sill.
- If you want to change your tire profile, ensure you also change your rim’s diameter to a size that works with the new tire profile to achieve the recommended wheel diameter.
You could also get the same wheel diameter problem when:
- You have a puncture. A flat makes a wheel sink low hence reducing its effective circumference.
- You are driving on a donut spare wheel. They are smaller than stock wheels and will give inappropriate readings.
- Your tire or tires are underinflated and deforming more, giving them a smaller effective circumference.
Your Vehicle is in Limp Mode
If your power train control module and the ECU detect a severe problem in the engine or transmission that could lead to catastrophic failure, should you continue operating your vehicle. Usually, they will put it in limp mode.
Limp mode limits the engine’s power output, forcing you to drive at a sluggish pace. The goal is to put a minimum strain on vehicular systems while giving you enough power to limp home or a nearby garage.
With limp mode on, virtually every error light on your dashboard will light up. Traction Control off will be one of them.
Start by fixing issues leading to limp mode first. Chances are this will get rid of the block on traction control hence restoring the system and turning off the light.
Any Issue With the Wiring or Control Module
Finally, you could get the service traction control error if there is a wiring problem with one of the sensors or an issue with the control module.
Electrical gremlins are common in water-damaged vehicles. A problematic traction control system is one of these gremlins.
You will need a competent auto electrician with good scan tools to pinpoint the electrical problem. They could range from something as simple as a loose sensor cable to something as complex as a damaged or fried control module.
Traction Control Needs Reprogramming
Under rare scenarios, some manufacturers’ traction control systems get software glitches that can only be fixed by reprogramming. If everything else checks out and you still have the error, consider getting a mechanic or the dealer to reprogram the system.
How to Service Traction Control
Servicing traction control could involve checking all the possible things that could go wrong in the system. Start with a comprehensive OBDII scanner and act on any pending or current errors stored there.
Additionally, you can dig deeper to check that the wheel speed sensors and steering angle sensors are working fine.
Some simple but valuable preventative servicing tasks include:
- Ensure that you use the correct size wheels
- Keep your tires inflated to the vehicle’s recommended pressure
- Keep your wheel wells and tires clean and free of caked mud or ice
- Frequently inspect your wheel speed sensors and ensure the harnesses are firmly plugged
Apart from this, there is little to service on your traction control system. They are robust units built to last, and in most cases, the error will only pop up because you have the wrong tires, turned the system off, or have a faulty sensor is very high mileage vehicles.
Traction Control Light On and Car Won’t Accelerate.
Since the traction control system affects a vehicle’s stability and driveability, many manufacturers feel that their cars won’t be as safe as they should be with the system off.
Some family and luxury vehicles opt to limit power output when they detect a fault in the system. This will, in turn, affect your vehicle’s top speed and how hard it can accelerate.
ProTip: This is very rare, and most cars will keep driving even with traction control off.
Can I Keep Driving With the Traction Control Light On?
Yes. You can keep on driving with the traction control light on. The vehicle will keep operating as usual, but you will be more prone to slipping, skidding, and spinning out since the traction control system isn’t available to mitigate such a scenario.
If you are driving on a dry surface, you could keep going but drive very carefully and at a considerable speed. Since faulty traction control could also affect StabiliTrak in GM vehicles, ABS and other electronic brake force distribution systems, your vehicle will handle the braking and accelerating very differently.
If you only have the Traction Control light on, confirm that you (or someone else) didn’t turn it off. Drive carefully home and make plans to troubleshoot and fix the problem as soon as before.
We all want our vehicles as safe and easy to drive as the manufacturer intended. Don’t we? Oh – and some insurers might downgrade settlements or decline a claim if they realize you were knowingly driving a vehicle with a crucial safety system like traction control faulty.