5 Reasons the Service AdvanceTrac Warning Light is On (And How to Reset It)
If you own a Ford vehicle, you’ve probably seen the “Service AdvanceTrac” warning on the dash. While there are many reasons this light may be illuminated, it is possible to reset the warning yourself.
WHAT IS ADVANCETRAC?
AdvanceTrac is Ford’s branding for their electronic stability control system. A stability control system uses wheel speed sensors, steering inputs, and yaw sensors to determine a vehicle’s path relative to the driver’s intentions. The system then provides corrections to prevent skids and slides, allowing the driver to maintain control over the vehicle.
If a driver is steering to the right but the vehicle is traveling straight, the AdvanceTrac system may reduce engine torque or apply the brakes to the right wheels to correct the vehicle’s path. This points the nose of the vehicle in the same direction as the driver’s steering input.
AdvanceTrac makes it easier to drive in inclement weather, and can quickly detect traction loss. The brakes can be applied to even a single wheel if necessary.
WHAT TRIGGERS THE “SERVICE ADVANCETRAC” WARNING LIGHT?
There are several failures that could trigger a Service AdvanceTrac warning light. Here are some of the possible causes.
1) Bad Wheel Speed Sensor
A wheel speed sensor (also called an ABS sensor) is embedded into each of the four wheel hubs. These sensors detect the speed at which each tire is spinning. The ECU maintains this data and uses it to determine a vehicle’s trajectory, and when one or more tires have lost traction.
A bad wheel speed sensor may not send this data to the ECU. With incomplete sensor data, the AdvanceTrac system will not be able to adequately measure and correct vehicle trajectory. This would trigger a warning light.
2) Mismatched Wheels or Tires
Many owner’s manuals include a warning that vehicle modifications may adversely affect the stability control system. Fords are no exception.
If your vehicle has any modifications to the wheel or tire size, or you’re running a mismatched set of tires, the stability control system may find certain sensor values to be outside the acceptable range for normal operation.
Although the tires may appear to be the same shape and size, mismatched tires will give different wheel speed sensor readings. In this case, it may be hard for the AdvanceTrac system to control the car in the event of a skid.
The AdvanceTrac system was programmed to work for a specific tire diameter.
3) Broken Clock Spring
A bad clock spring (also called a spiral cable) is a coil of wires that feeds power to the steering angle sensor, the steering wheel buttons, and the airbag.
A broken clock spring could interrupt the signal between the ECU and the steering angle sensor, rendering the AdvanceTrac system inoperable. In this case, you will notice other symptoms such as broken steering wheel controls and an airbag warning light.
4) Limp Mode
If your vehicle has entered limp mode, chances are the AdvanceTrac system will not work. Limp mode triggers several warning lights, and among these is often the Service AdvanceTrac warning.
5) Bad Ground or Wiring Issue
A bad ground can cause all sorts of problems with sensors, depending on the ground location and which sensors are on that part of the circuit.
If you think you have a bad ground, first check that all your ground straps are connected with a clean and tight connection. If multiple sensors are acting up, this may help you narrow down the location of the bad ground.
You may need to use a wiring diagram from a repair manual to help you track down the source of the problem.
CAN YOU DRIVE WITH THE SERVICE ADVANCETRAC LIGHT ON?
It is possible to drive with the Service AdvanceTrac light on. If you decide to do this, keep in mind that your stability control system may not function correctly, if at all.
If you are driving on a perfect sunny day, this is not much of a concern. However, if you are driving in inclement weather, you may want to think twice before going too far with the AdvanceTrac warning light on.
If you have some seat time at a car control event with professional instruction, you may be able to get along just fine without stability control. Some examples of such events are high performance driver education and autocross.
HOW TO RESET THE ADVANCETRAC LIGHT?
Like a check engine light, the best way to reset the AdvanceTrac light is to identify the problem that caused the light in the first place and correct that problem. If you think the Service AdvanceTrac warning was an error, a high quality automotive scan tool should be able to reset the warning light.
Barring that, you should be able to reset the AdvanceTrac light by disconnecting the ground terminal of the battery. After the battery is disconnected, hold the brake pedal for a few seconds to make sure any power left in the system is discharged.
Next, reconnect the battery. Do note that this procedure may reset some unrelated settings in the vehicle, such as the radio or clock.