If your Buick ABS and Traction lights stay on, it means the Electronic Brake Control Module (EBCM) has detected a problem. In most cases, the problem is caused by a bad wheel speed sensor.

With the ABS light on, your wheels may lock up during emergency braking which could result in the vehicle skidding. Your car may require a longer distance for braking or even lose traction when going around sharp curves.

Buick EBCM problems disable both the Anti-lock Brake System (ABS) and Traction System (TCS). Buick ABS problems can be diagnosed with an ABS scanner. 

Symptoms

Common symptoms you will notice when your Buick ABS fails:

• ABS light stays on
• Trac Off warning
• Wheels lock-up under hard braking
• Brake light on
• Service Traction Control System light on
• Service Stabilitrak light on

Even though the vehicle may operate, get the ABS diagnosed as soon as possible.

In addition to the warning lights, you may also hear a brief and intermittent noise, click, grinding, or ABS pump motor noises from the inside of the vehicle at parking lot speeds when braking.

You may also notice a Service Message displaying in the Driver Information Center (DIC).

What to do when Buick ABS, BRAKE, TRAC light come on

The first thing that you should do is to safely pull over and check the brake fluid level.

Open the hood by pulling the hood release under the hood. Next, locate the brake reservoir on the driver's side of the engine.

Look at the side of the reservoir for Min and Max marks. Verify the brake fluid level is between Min and Max marks.

Do not operate the vehicle if the brake fluid level is below the MIN mark.

If the brake fluid level is within the recommended range, continue to the next step to diagnose the problem with an ABS scanner.

How to Diagnose Buick ABS problems

To diagnose Buick ABS problems you will need an ABS scanner.

1. Park your vehicle and turn off the engine.
2. Connect the scanner to the diagnostic port under the dashboard.
3. Turn on the ignition. You don't need to start the engine.
4. Turn on the scanner. Select Buick from the main menu. Select the ABS system under Control Units. Read Fault Codes to find out why your ABS light is on.

If you use a generic OBD-II scanner, you may not get any codes at all. When you use an ABS scanner you will get fault codes such as:

• C1214 pointing to the Electronic Brake Control Module (EBCM) failure.
• C0035 Left Front Wheel Speed Sensor Circuit
• C0040 Right Front Wheel Speed Sensor Circuit
• C0045 Left Rear Wheel Speed Sensor Circuit
• C0050 Right Rear Wheel Speed Sensor Circuit Plausibility Failure

Possible Problems

One of the most common problems that trigger Buick ABS and traction problems is a faulty ABS wheel speed sensor or debris at the tip of the sensor.

A list of possible problems that cause Buick ABS and traction control problems.

• ABS Wheel Speed Sensor - The ABS sensor is mounted at each wheel hub. In some models, the ABS sensor is integrated into the wheel hub. Dirt at the tip of the sensor can also trigger the ABS light.
• Steering angle sensor - Steering angle sensor is mounted on the steering column, below the steering wheel. It can fail, which triggers the ABS and traction control lights because the EDC module does not know the position of the steering wheel.
• Damaged wiring harness - Wire harness that goes to the ABS module or wheel speed sensors may get damaged. The wires can get corroded or may also get damaged in an accident.
• Faulty ABS pump - ABS pump itself can fail. Contacts inside the circuit board break or the brushes for the ABS motor may wear out. You can remove the old ABS pump and ship it a vendor that offers the ABS module rebuilt service. Technicians can repair your old unit which is a lot cheaper than replacing the ABS module.
• Brake light switch - A faulty brake light switch can trigger the vehicle to turn on the ABS light or prevent the transmission to come out of Park.
• Bad relay - A faulty ABS module relay can get stuck or stop working.
• Low brake fluid - Low brake fluid can trigger the Brake light and in some cases the ABS light.
• Poor ground connection - Poor ground connection between the engine and the ABS module can trigger the ABS light.
• Low battery voltage - On newer Buick vehicles the ABS light may come on if the battery dies. The ABS and traction control warnings should reset after you drive the vehicle for a couple of minutes.
• Dirt or debris on the ABS sensor tip - Dirt can accumulate at the tip of the ABS wheel speed sensor. This condition can prevent the ABS sensor recording the correct wheel speed.

To find out why your Buick ABS light is on, you need to read the fault codes from the ABS module.

You can't use a generic scanner to retrieve ABS codes. You will need a scanner that works on Buick and can diagnose the ABS modules such as Foxwell for GM Buick or Autel All System Scanner.