From Headlights to Taillights: Skidding in a Winter Wonderland

By Mark Kozemko, Johnson College’s Automotive Technology Program Director

Original published in the December 25, 2020 edition of the Valley Advantage.

So far we’ve been lucky in terms of snow fall and accumulation this year, but as we know, that can change in a heartbeat here in NEPA. The topics of snow and cold caused some to reach out about questions regarding their vehicle’s anti-lock brake and Traction Control systems.

What are anti-lock brakes?

The anti-lock brakes system — or ABS, as it’s referred to in the automotive industry — is a system that keeps your brakes on each wheel from locking up and causing a skidding condition. When wheels lock up and skid on the road surface, you have no control and cannot steer the vehicle away from possible obstacles.

How do anti-lock brakes work?

In our previous columns we mentioned how smart our vehicles are becoming. ABS makes them even smarter. Sensors in each wheel send a signal to an ABS control unit. These sensors tell the controller when a wheel is locking. The control unit then sends a signal to a solenoid that controls the hydraulic pressure to that wheel. The pressure is decreased and the wheel is allowed to keep spinning. This keeps traction on the road surface so you can safely steer the vehicle.

If your vehicle is equipped with ABS and you are driving in the snow, you don’t need to pump the brakes, but you will feel the brake pedal vibrate and you may hear some unfamiliar noises. Don’t let these vibrations or noises make you take your foot off the brake pedal. The vibrations and noises are letting you know the system is operating properly and doing its best to keep you in control of your vehicle. Taking your foot off the pedal will just deactivate the ABS system and decrease your ability to safely steer your vehicle.

What is traction control?

If your vehicle is equipped with ABS, chances are it’s also equipped with traction control. Traction control works just the opposite of ABS — it stops wheels from spinning and slipping. For instance, traction control senses that a wheel is spinning and the control unit increases hydraulic pressure to that specific wheel to stop it from spinning.

How does traction control work?

I’m sure you’ve seen videos of vehicles stuck in the snow and wheels spinning out of control and the vehicle not going anywhere. With traction control, the spinning wheel has a sensor that tells a control unit, “I’m spinning and can’t seem to stop!” The control unit sends a signal to that same solenoid I mentioned above, but this time, instead of reducing the hydraulic pressure, it increases the pressure to slow down the wheel. When this happens, the other wheels gain more traction and in most cases, will pull the vehicle out of a stuck situation.

Traction control also helps vehicles take corners better and make it around bends in the roadway without crossing the center line or having the rear of the vehicle trying to slide around the bend before the rest of the vehicle. In other words, it helps correct under-steer and over-steer.

What is correct under-steer and over-steer?

Let’s say, you’re traveling a bit too fast around a bend, and you go to turn the steering wheel but the vehicle continues to go straight. This is called under-steer. What’s happening is the front end does not follow your intended course. Sensors in the vehicle identify this problem and attempt to make corrections by braking certain wheels that will change the direction and help the vehicle make the bend. This specific under-steer situation usually occurs on front wheel drive vehicles.

If the rear of the vehicle slides across the center line, it’s called over-steer. Again, sensors in the vehicle will sense this situation and attempt to correct by braking the wheels necessary to get the vehicle around the bend safely.

Remember, ABS and traction control work together to help keep your vehicle and occupants safe. These options are standard equipment on just about all new and late model vehicles. Make sure you let them do their job and don’t let noises and vibrations make you let up on the brakes, especially now that the cold is here and snow is soon to follow.

From Headlights to Taillights: Clearing the Air

By Mark Kozemko, Johnson College’s Automotive Technology Program Director

Original published in the September 4, 2020 edition of the Valley Advantage.

We all try to breathe the cleanest air possible. Our body’s natural air filter located in our breathing system usually does a fine job. Unless, of course, we have a cold or allergy which results in a stuffy nose. When this happens we can’t breathe properly. The condition makes us feel tired and sluggish. We’ve all been there, right?

If your vehicle’s engine or heating, ventilation and air conditioning (HVAC) breathing systems can’t breathe correctly, your vehicle gets tired and sluggish, too. This is caused by your vehicle’s air filters not performing properly due to being dirty, or simple wear and tear.

Today, we’re talking about air filters that help your vehicle breathe. Below are a few questions I received about vehicle air filters. So let’s get started.

The first question is, “Are there different types of air filters in a car, and what do they do?”

Yes, each vehicle has different types of air filters. Late model vehicles have at least two different air filters as standard equipment. The first filter is the engine intake air filter and the second is the heating/cooling system intake air filter, or cabin filter. If you have a vehicle equipped with air brakes, normally a heavy duty truck, it will also have an intake air filter for the air compressor, which is the heart of the air brakes.

Now let’s talk about what each one does for your vehicle.

The engine intake air filter is designed to filter the air that the engine uses for combustion in the cylinders. Not only does it filter the air going into an engine, it allows the proper amount of air in to produce optimum combustion. When an engine intake air filter is dirty, the air flow becomes restricted and combustion may not be complete. The restricted air flow causes an engine to run poorly and use more fuel because the cylinders are not getting the correct amount of air. This condition will decrease fuel mileage and may also cause black smoke from the exhaust.

The cabin air filter filters air coming into the passenger compartment/cabin. Modern vehicles have systems constantly circulating air through the cabin using outside air. The filter catches pollutants, debris and allergens that can get into your vehicle. This filter can get clogged and pretty nasty. If you ever see a dirty cabin filter, it will make you wonder about the air we breathe on a regular basis.

The intake air filter inside air brakes filters air taken into the compressor used to operate the air brake system. Needless to say, if this filter blocks up and restricts air flow to the compressor, the results can be devastating because the brakes will not work.

You vehicle’s air filters should be checked often. If the filters are left unchecked, engines may run poorly, cabin air quality and air flow may diminish, or brake systems will not function properly.

“How often do they need to be changed?” is our second question.

Manufacturers suggest service intervals for each of the air filters in your vehicle. These service intervals are for vehicles driven in what manufactures call normal conditions. Driving on dirt or dusty roads, through construction areas — we know there are plenty of those in northeastern Pennsylvania — and poor air quality are contributors to decreasing the lifespan of your air filters. At the very least, you should always follow the service and replacement intervals noted in your vehicle’s owner’s manual. As with any service, it doesn’t hurt to do it more often but I recommend that you don’t extend the time between air filter services.

Our final question is, “Can the filters be changed by owners or must they be changed by technicians?”

If you’re an owner who is comfortable performing some of your own maintenance, you shouldn’t have any challenges replacing the engine intake or cabin filters. Keep in mind some cabin filters are very hard to find because they’re tucked under the dashboard. If you’re not comfortable, by all means, have your repair shop do the service.

You may not see your vehicle’s air filters or even think about them often, but they do need your, or a service technician’s, attention from time to time. They’re vital to keeping your vehicle performing efficiently and making sure you and your passengers breathe the cleanest air possible.

The next Headlights to Taillights column will be published in the September 25, 2020 edition of the Valley Advantage.