Check VSA System Light On (5 Causes and What It Means)
Have you ever had the “Check VSA System” warning light come on when you started your car? Maybe you’ve even seen the light flash while driving. If you’ve owned a Honda or Acura for a while, there’s a good chance you’ve seen the “Check VSA System” message on your dashboard.
Here’s some information on what the light means, why it comes on, and what to do next.
What is the VSA System? The VSA system is Honda’s Vehicle Stability Assist, an electronic driver assistance system developed by Honda. This system is used in most current Hondas and some Acuras (Acura is Honda’s performance and luxury division in North America).
The VSA system includes both traction control and stability control. It is connected to the anti-lock braking system (ABS). In fact, the VSA system is controlled by a module called the VSA Modulator, which is essentially the same as the ABS module. Nearly all modern cars have some sort of traction and stability control system. The names of these systems vary by manufacturer, but the principles are the same, even if the algorithms and implementations vary slightly between brands and models.
Traction control systems (TCS) reduce engine torque and/or apply the brakes to certain wheels when accelerating on slippery surfaces. Stability control helps keep your car in the direction you’re steering if it starts to skid.
Anti-lock braking systems (ABS) help you stop as quickly as possible without locking up your tires. This is because a rolling tire has more grip than a sliding tire.
What does the VSA light mean? When the VSA light is flashing, it means the system is working properly. The VSA light flashes when traction is reduced and the VSA system steps in to keep your car moving. Snow or ice makes the VSA light more likely to flash. This condition should be found in your owner’s manual, which may contain more specific information for your vehicle model.
If the light stays on:
If the VSA system indicator light is on, it typically indicates that there is a problem. This is often caused by a failed sensor, an electrical problem, or a loss of communication between the vehicle’s sensors. Often, a diagnostic tool can give you more information about the exact cause of the problem.
Mechanics are equipped with specialized scanners that can give you much more information than you can get at your local auto parts store. If you want to scan the codes yourself, see the list of professional scanners below.
How does a VSA system work? A VSA system reads inputs from wheel speed sensors at all four corners, steering angle sensors, yaw sensors, and possibly other sensors. An algorithm in the control module compares the expected yaw rate to the actual yaw rate based on various sensors around the vehicle.
If the expected yaw rate is outside a specified tolerance compared to the actual yaw rate, the stability control system applies brakes to individual wheels to correct the vehicle’s course. Some newer vehicles can also apply their own steering inputs. Applying steering inputs automatically is also how Honda’s Lane Keeping Assist System (LKAS) works.
Causes of the “Check VSA System” Warning
1) Faulty Wheel Speed Sensor
The VSA system needs to see data from all four wheel speed sensors to function properly. A failed wheel speed sensor can cause the VSA warning light to come on.
2) Faulty VSA Modulator
The VSA Modulator is an ABS module. It uses an algorithm developed by Honda to control the brakes on each wheel separately. If the VSA modulator is defective, the ABS, traction control, and stability control systems may not function.
3) Faulty Clock Spring
The clock spring is a spiral coil of wire that keeps the steering wheel electronics running while you turn the steering wheel. If the clock spring fails, other problems may occur, such as: airbag warning light, no horn, steering wheel controls not working. The VSA system can be powered by the clock spring.
4) Bad Yaw Sensor
The yaw sensor is an advanced acceleration sensor that detects how hard you are cornering. If the yaw sensor is sending incorrect data or loses communication, the VSA warning light may come on.
5) Mismatched Tires
The VSA system algorithm assumes that all four tires are approximately the same circumference. If one tire has a different diameter than the others or has a significantly shallower tread depth, it may confuse the VSA system.
The VSA system may think that the wheel speed sensors are providing incorrect data, even when the wheel speed sensors are functioning properly. Manufacturers allow for a small margin of error since tires can vary by as many as 32 inches. Consult your owner’s manual for more information on this, especially if your vehicle is equipped with all-wheel drive (AWD).
Can I drive with my VSA light on?
If the weather is good, it’s usually safe to drive with your VSA light on. If the weather isn’t looking good, you might want to reconsider. A little rain is OK, but if you’re worried about hydroplaning on standing water or slipping on ice, it may be best to wait until the roads are clear.
You’re probably also good to go if you have some experience with a car control course or high performance driving event (HPDE). After you’ve gained some experience driving your car at the limit, you’ll understand more about vehicle dynamics. Stability control is designed to compensate for lack of driver experience when loss of traction occurs.
If other warning lights are illuminated such as the check engine light or ABS light, it’s probably best to get the vehicle repaired as soon as possible. It is recommended that you identify the root cause of the problem before you drive any significant distance in this case.