- The TC warning light will flash in low traction conditions on most vehicles.
- If the TC light remains steadily illuminated at all times (with the system enabled), it means there’s a problem with the traction control or a related system that needs to be fixed.
- Some of the most common triggers of this warning light include sensor issues, control module and network problems, circuit problems, and issues with the hydraulic control unit.
Your car has many different dashboard warning lights, one of which is the traction control warning light. When the traction control (TC) light turns on, there may be a problem with your vehicle, or it could just be normal system operation, depending on the situation.
Regardless, you’ll want to know what triggered the light to ensure your vehicle continues to operate safely and reliably.
Traction Control Light Meaning
TC has been mandatory on all vehicles built in the United States since 2012 when a related system, called stability control, became a requirement. As you might guess, your car’s TC system is designed to limit wheel slip during acceleration to improve traction.
Your car is equipped with a dashboard warning light to keep you informed regarding the state of the TC system. Depending on the situation, the light can either indicate normal TC operation or a problem with the system.
On most vehicles, the TC warning light will flash in low traction conditions. A light related to the traction control system will also illuminate if the driver turns the traction control system off. In both of these scenarios, the TC light is normal and does not indicate a problem with the system.
But if the TC light remains steadily illuminated at all times (with the system enabled) there is a problem with the TC or a related system that needs to be addressed. The vehicle will disable TC operation until the problem is fixed.
In such a scenario, usually, the antilock brake system (ABS) warning light will also turn on. Plus, you may notice that the vehicle stability control (VSC) light and other warnings illuminate.
How Does Traction Control Work?
When your car starts to lose traction, the TC system uses the brakes to limit wheel slip. The TC system is an extension of the ABS system, which means both primarily rely on the same components.
Key aspects of both systems include a control module (usually, the ABS module), the ABS wheel speed sensors, and the ABS hydraulic control unit. A typical hydraulic control unit contains a collection of solenoid valves and a pump motor, all of which work together to modulate fluid pressure to the brakes.
Whenever the vehicle is in motion, the ABS module monitors the wheel speed sensors. If the sensors indicate one or more of the wheels are slipping, the module will operate the hydraulic control unit to modulate the brakes on the drive wheels to help regain traction.
Most TC systems also work with the engine and transmission control systems to limit wheel slip. In a typical setup, when the ABS module perceives one or more of the wheels to be slipping, it sends a request to the engine control module (ECM) to reduce engine output. The ECM will respond by reducing the throttle opening, limiting fuel injector pulse, retarding ignition timing, or applying a combination of strategies.
The ABS module may also request that the transmission control module (TCM) upshift the transmission to reduce the amount of torque sent to the drive wheels. All of the modules communicate together over a data network.
It’s important to note that the ABS and TC systems are usually integrated with a vehicle stability control (VSC) system. The VSC system modulates brake pressure to the wheels as needed to help the vehicle maintain directional stability.
What Causes the Traction Control Light to Come On?
The TC Light can either indicate normal vehicle operation or a problem with the system, as we’ll discuss below. It’s a good idea to consult your owner’s manual to better understand the role of the traction control light for your particular application.
Traction Control Activated or Turned Off
Many vehicles flash the TC light when the system is active during low traction conditions. Also, most cars give the driver the option of turning the TC off. When the TC is disabled, an indicator related to the TC system will illuminate on the dashboard. Both conditions indicate normal operation and do not point to a problem with the TC system.
A Problem with the TC System
When the TC light remains steadily illuminated at all times (with the system enabled) there is a problem with the TC or a related system that needs to be addressed. The vehicle will disable TC operation until the problem is fixed.
Some of the most common problems that can trigger the TC warning light include:
- Sensor issues
- Control module and network problems
- Circuit issues
- Problems with the hydraulic control unit and related components
If the TC light remains steadily illuminated at all times (with the system enabled) there is a problem that needs to be addressed. In such a situation, usually, you can technically continue to drive the vehicle.
However, the TC system will no longer work, which can compromise the vehicle’s overall safety. So, you’ll want to address the problem as soon as possible.
As was mentioned, there are instances where the TC light may turn on during normal operation. But if there is an actual problem with your vehicle that’s causing the TC light to remain illuminated, you (or your mechanic) will need to do some troubleshooting to determine what’s causing the problem. The root cause of the issue could be anything from damaged wiring to an issue with the control module.
When the control module recognizes there’s a problem with the TC system, the device turns on the TC warning light and stores a corresponding diagnostic trouble code (DTC) in its memory. Most professionals will begin the troubleshooting process by using a capable scan tool to retrieve those codes.
Although the codes don’t tell you exactly what’s wrong with the vehicle, they do provide a starting point for further diagnostics. What the rest of the troubleshooting process involves will depend on which codes are stored.
Once the underlying issue has been fixed, the codes can be cleared with a scan tool. Clearing the codes will extinguish the light.
Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.