Anti-Lock Brake Systems Help Keep You Safe

Understanding ABS Keeps You From Accidentally Turning the System Off

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Your pickup truck's anti-lock brake system (ABS) is one of the most important automotive safety advancements since the seat belt. Most drivers know that having anti-lock brakes is a good thing, but they often don't understand how the system works.

Conventional Brakes vs. ABS

Conventional Brakes

A vehicle equipped with conventional brakes only knows how hard you’re pushing on the brake pedal. There’s no way for the vehicle to know that you’re on a slippery surface, that you just splashed through something slick like oil or antifreeze or that you’re just pushing the brake pedal too hard.

The result of any of these situations is a skid as the brakes clamp your wheels to a halt and the tires smear themselves over whatever you’re surface you’re on. When you’re in a skid, say goodbye to your ability to steer or slow down any faster. If you’re skidding on a fairly grippy surface like pavement, you might say goodbye to your tires, too, as they scrape a large amount of rubber off of the area that’s kissing the ground.

There are techniques that skilled drivers use to avoid locking the wheels when braking in a vehicle without ABS. The arts of Cadence Braking and Threshold Braking involve pumping your vehicle’s brakes just up to the point where you feel your brakes begin to lock, then releasing pressure on the pedal shortly before putting more force on the braking pedal again.

Anti-lock Brakes
Anti-lock brakes bring the skills of Cadence and Threshold Braking to every driver. Speed sensors mounted at the wheels check rotating speed constantly every second.

When the rotating speed of one or more of the wheels drops, the Electronic Control Unit (ECU) is alerted immediately. The ECU, the brain of your ABS system, then immediately commands the brake system to release pressure on the wheels. The pulsing sensation of an ABS system comes from the number of times the system re-checks wheel movement and adjusts pressure when your hold down the brake pedal—up to 15 times per second in modern ABS systems.

Unless you’re part-octopus, you are simply not able to adjust pressure on your braking system at that rate and should see much shorter stopping distances as a result. Remember to keep your foot planted on the brake pedal even though the pulsing of an ABS system at work might feel like something’s wrong. Your ABS system may shut off if you release the brake pedal in an emergency, and you’ll lose precious stopping distance if you still need to scrub off some speed.

 

Anti-Lock Brakes Make New Safety Technologies Possible

Anti-lock brake technology opens the door to the modern age of intelligent driving systems. Engineers found they could use an anti-lock brake system to detect and control wheel spin as you accelerate, giving birth to traction control systems. Later saw the addition of sensors, some of which are related to the ones used by your cellphone to detect motion and measure force, to monitor the path your vehicle is headed in and can see when you’re starting to slide off your trajectory (imagine driving through a sharp turn too fast). Using that information, the anti-lock brake system becomes your vehicle’s stability control system, applying brake force to the appropriate wheels to minimize the slide and put you back on track.

Modern evolutions of stability control include applications like tow control and the new Pro Trailer Backup Assist on the 2016 Ford F-150. Coming marvels like self-driving technology would never be possible without an ABS system.

Not All Anti-Lock Braking Systems Are Equal

Before the modern age of the daily-driver, family-friendly pickup truck, light trucks were outfitted with simpler ABS systems that weren’t as effective as those on cars. The main difference between ABS systems is how many channels they have. Modern 2-channel ABS systems have two modulators—the device that controls brake pressure—working to manage the front and rear pair of wheels. 3-channel systems minimize lock-ups by typically using two modulators for the front wheels and one for both rear wheels. 4-channel systems use one modulator for each wheel.

1-channel systems are common in older rear-wheel drive pickups where both rear wheels are adjusted at the same time. In a 1-channel system it’s common for one rear wheel to lock up before the system kicks in.

What Type of ABS System Does Your Truck Have?

One popular way of checking to see what type of ABS system your truck has is to check behind the hub of your wheels.  If you see a wire behind the hub of each rear wheel, you have a 4-channel system. If you don’t see anything, check behind the hubs in the front of your truck. If you see a wire behind the front hubs, you have a 3-channel system…the speed sensor for the rear wheels is in your rear axle. If you don’t see anything, then your only speed sensor is in your rear axle, meaning you have a 1-channel ABS system.

Edited by Jonathan Gromer