Common Problems with ABS Brakes

ABS brakes have been around since the 70s on full production automobiles. As we got into the 80s they became more commonplace. In the 1990s it went from being a sales tool to standard equipment as the technology improved. Car makers learned from mistakes made on previous generations to improve anti lock reliability going forward. Evolution of these systems allows us to apply a general rule of thumb. The older the system, the more likely they are to experience problems. In this article we’ll talk about how to find common problems on certain model vehicles. We will also discuss basic system operation and why some parts are more likely to fail than others. Discover the difference between ABS and check engine lights when it comes to recording and clearing codes set in memory.

Diagnosing Problems

The ABS system includes on board diagnostics that can be accessed with a scan tool. Set trouble codes can help identify the source of the problem. Each of these codes represents a specific area. A factory service manual will contain a detailed step-by-step troubleshooting chart for each of these trouble codes. Unlike the check engine light, after a repair is completed codes will often be reset automatically after a drive cycle confirms proper operation. This means the light will go off by itself after the issue is fixed.

How a Wheel Speed Sensor Works.

One of the components that the anti lock system relies on heavily is the wheel speed sensor. The control module receives input signals from these sensors on rotational speed. The component generates its own AC (alternating current) signal. It’s mounted closely to a toothed ring that looks like a gear with large cogs. As each individual tooth passes the permanent magnet sensor a sign wave is generated. The end result is a pulsing signal that is sent to the brake control module which in turn translates this into a wheel speed.

ABS Speed Sensor Problems

These parts are susceptible to damage because of their location under and outside the vehicle. Many common problems can be generated from missing teeth from the ring or wheel speed sensor damage. A few examples would be systems that go active at low speeds or intermittent operation. When there’s no signal detected from an individual sensor a trouble code will set and the amber ABS light turned on. Accessing this code can send you directly to the part that is malfunctioning. If a speed sensor code is set the system will ignore that wheel and therefore will not activate the ABS during a panic stop.

Finding Common ABS Problems on Specific Vehicles

There is an article here on answers.com/auto repair that talks about common complaints from drivers and discusses the detailed operation of the ABS light and the red brake warning light. This is good reading for those interested in learning about the anti lock system and things drivers complain about that could be normal such as noise or brake pedal feedback.As mentioned above ABS braking systems have been evolving since the 70s and have come a long way since then. Unfortunately people with vehicles from the 80s and 90s might feel they were guinea pigs in some kind of experiment. As vehicle manufacturers rolled out new technologies not all worked well in the field. Different types of systems wound up having short production runs because better solutions were discovered.The best way to handle an older vehicle with an ABS light is to gain access to vehicle specific TSB’s (technical service bulletins) issued from the factory. This can cover known problems providing specific answers from the people that built the vehicle. You’ll find that most of the companies that provide these factory issued TSB’s offer some kind of subscription service where you pay a small amount for a certain length of time.

Refrain from Acting on Unverified Information

If you tried searching through forums and publicly released information for a keyword string like “abs technical service bulletin 96 Pontiac Grand Prix” you find a wide range of results. Looking deeper into these results reveals a lot of unverified information and short articles leading you back to the paid sites that sell the factory released TSB’s. We all love free stuff but when it comes to the brakes on your car the factory that built it provides the best quality service and repair advice.

When the vehicle has an ABS warning light the most efficient way to repair it is to retrieve the code and follow a diagnostic tree chart for that particular failure. We also learned that the older the system is the more likely it will have a weak link in the chain. These specific weak points are often identified in manufactured issued service bulletins. When it comes to common problems with ABS brakes across the board wheel speed sensors are the most susceptible component to external damage from road debris. Inspecting these components is a good place to start when looking for common problems.