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Red brake light causes and diagnostics

In Automotive Diagnostics, Brakes by HomeTowne Auto Repair & Tire

We worked on a Toyota 4Runner that had its brake light turn on. 

The brake pedal also didn’t feel right and the brake fluid reservoir was empty. Our technician didn’t see any brake fluid leaks.

Diagnostic testing was needed to determine the cause and any needed brake repair.

We started with a brake fluid exchange. This brought the brake fluid reservoir back to where it needed to be and restored the brake pedal.

Brake fluid exchange on a Toyota 4Runner.
Brake fluid exchange on a Toyota 4Runner

Why did my brake light turn on?

The red brake light is supposed to be appear when your parking brake is on. If it doesn’t turn off when you release the parking brake, it could be hinting at an underlying problem.

Parking brake system issues: If the red brake light stays on, you may have a switch problem in your parking brake pedal or handle. 

Electrical issue: On newer vehicles, it could indicate you have a parking brake issue because everything is electronic now. So, if the motor isn’t in the right position when you’re moving, it might throw that brake light on.

Low brake fluid: The brake light might also appear on your dashboard if the brake fluid isn’t at the right threshold.

Empty brake fluid reservoir on a Toyota 4Runner.
Empty brake fluid reservoir on a Toyota 4Runner

ABS problem: For some cars, an anti-lock braking system (ABS) issue will prompt a bunch of lights to come on – possibly the ABS light, traction control light, and brake light. It can be an extra indicator that something is going on.

Brake pads: European vehicles will have brake pad wear sensors that trigger the light when it hits a certain measurement and tells you that you need brake pads. 

What does diagnostic testing look like?

As we begin brake light diagnostics, we note any related concerns that a customer mentions.

Our technicians usually start with looking at the parking brake and brake fluid.

For the parking brake, we want to make sure the parking brake switch is disengaged and not sending a signal to the car saying the parking brake is on.

The brake fluid level is inspected, too. 

A code scan is also a part of the diagnostic process.

Our next steps will depend on what we find initially. A parking brake-related problem would lead us to check travel on the cable and the switch.

Low brake fluid might indicate a brake fluid leak. There could be an external leak, such as a fitting, line, or brake caliper. 

If we can’t see an external leak, we need to investigate internal leaks, which would be in the master cylinder. The master cylinder bolts to the booster that has a diaphragm. The brake fluid can go in there and you won’t see it because it gets burned up in the engine. 

Resolving brake problems

Does your braking system seem off? Maybe it’s taking longer to stop your vehicle. Some drivers feel like the brake pedal is going to the floor or they have a hard brake pedal.

You may also get brake pulsations in the front or the rear. This will feel like shaking in the steering wheel, pedal or seat.

Motorists might hear a grinding noise or squealing sound, as well.

Make sure to get any brake problems you’re experiencing checked out by an auto repair shop. They could find that nothing is wrong, or your car might be due for brake maintenance.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Dale City, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Uncommon causes behind car no start conditions

In Automotive Diagnostics by HomeTowne Auto Repair & Tire

Often, we hear and talk about common reasons when a car won’t start.

Usually, the answer is a simple problem – the battery dies, there’s a bad alternator, or the starter is on its way out.

What many of us don’t consider is that there can be deeper causes behind a no start condition. These can include:

  • Malfunctioning sensors
  • Issues with tone rings
  • Chewed wires

No start on an Audi

We worked on an Audi A5 that stopped running and wouldn’t turn back on.

It was brought in with many codes, including one for a high pressure fuel pump and a code related to the crankshaft synchronization.

Codes on an Audi A5.
Codes on an Audi A5

A new high pressure fuel pump and crank sensor were installed, but the vehicle still refused to restart.

The culprit was a water pump sensor that was shorting out, which was figured out just by happenstance.

On this engine, the crankshaft sensor, camshaft sensor and other sensors run off the same 5 volt reference. The technician noticed the water pump was starting to seep. When he unplugged the water pump, the vehicle started.

After we replaced the water pump, the car worked fine.

Uncommon reasons why a car won’t start

The problem with the Audi doesn’t happen everyday. (In fact, our Service Manager had never heard of this in 20 years of being in the automotive industry.)

There are other culprits that – every once in a while – can lead to a no start condition.

Your camshaft and crankshaft sensors are the most common sensors that will cause this issue. If the car reads that the cam or crank aren’t correct, it won’t allow you to turn it on because it can damage the vehicle.

Tone rings can also cause some problems. We heard about a car that wouldn’t run after a motor replacement. The tone rings the sensors read off of weren’t in the correct position.

There’s a tone ring for all of these sensors to work. If you put the wrong tone ring in with the wrong sequence, the vehicle will get confused and refuse to start.

Wiring problems can occur, too.

Rodents love the taste of rubber installation and sometimes chew through wires. A car can be sitting for a couple of days and they will nest in the valley of the engine (where it’s warm). 

A few times a year, we work on vehicles that have phantom problems. They won’t have any codes or a starting point, and we’ll stumble upon a small nest. In this article, we talk about signs of rodents and how to deter them from making themselves at home in your car.

Figuring out the cause

If your car isn’t starting when you first get in, start with the basics – try jumping it or attempting to start it multiple times. Note whether you hear a clicking sound.

In most cases, the reason why a car won’t start can quickly be determined. However, there can be situations where the problem isn’t so easily explained.

After performing an electrical test and checking the starter, an automotive technician may recommend diagnostic testing. This would include looking up any codes using a scan tool and tracking down problems from there.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Dumfries, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Driveline service: How to take care of your vehicle

In Automotive Diagnostics, Vehicle Maintenance by HomeTowne Auto Repair & Tire

Whether you’re backing up or speeding ahead, your vehicle’s driveline is helping you get to your destination.

Every once in a while, driveline service is needed to keep you and your car on the road.

What is the driveline?

The driveline is responsible for moving a car forward or backward. How does it work? Well, there are different setups among vehicles.

Rear-wheel drive transmission.
Rear-wheel drive transmission

If you have a rear-wheel drive, the engine sends power to the transmission. The transmission gives the rotation to the driveshaft, which goes back to the rear differential. This causes the wheels to spin in whichever direction.

For front-wheel drive cars, power is transferred from the engine to the transmission and spins the axles.

On rear-wheel drive vehicles with all-wheel drive capabilities, to send the power or rotation to the front wheels, it needs to go through a transfer case and another drive shaft.

Front-wheel drive cars with all-wheel drive capabilities have a similar concept. Power goes from the engine to the transmission. The transfer case is either built into the transmission to go to the rear wheels or the transfer case is a separate unit that goes to the rear wheels.

Driveline problems we look for

We don’t look for one particular driveline problem when working on vehicles.

Front-wheel drive transmission.
Front-wheel drive transmission

Usually when a customer mentions a symptom, we can isolate it to a certain driveline component. Here are some examples:

Transmission: When it comes to the transmission, you could have slipping, shuddering, or hard shifts. Problems with switching gears and a grinding noise can be signs of a bad transmission.

Transfer case: If power isn’t getting to the rear drive shaft or front drive shaft, there may be a problem with the transfer case. Drivers might also notice a vibration or feel like their car is shaking when this part is bad.

Rear differentials and front differentials: The first thing you’re going to notice before it goes bad is noise, because those are rotating elements. You have bearings and gears that all flow together and are lubricated by fluid.

Driveline service and signs that it’s needed

Aside from a catastrophic failure, one of the most common driveline problems that drivers will notice is a roaring noise. It may sound like the tires are loud.

Vibration is another possible symptom. When driving at a certain speed and throttle position (or load), it might feel like you’re driving over a rumble strip.

Front differential for a four-wheel drive truck.
Front differential for a four-wheel drive truck

To ensure that the driveline continues working as designed, make sure that it receives needed maintenance overtime. You can take care of your driveline by regularly exchanging fluids on the transmission, transfer case and differentials. Sometimes, u joints may be serviced.

Our shop offers driveline service. This includes engine repairs, engine replacement, external transmission repairs, transmission replacement, and differential replacement. We also replace u joints, carrier bearings, and axle bearings. 

Transmission fluid exchanges, transfer case fluid exchanges, and differential fluid exchanges are some maintenance services our technicians perform.

So, if you think something is wrong with your driveline or it’s been a while since these components have been serviced, feel free to reach out to us.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Car vibrations and other strange road manners

In Automotive Diagnostics by HomeTowne Auto Repair & Tire

One of our customers was driving their Hyundai Sonata when they noticed an abnormal circumstance: it seemed to be running at a higher rpm while at a stop light.

We performed a smoke test on the intake system and cleaned the throttle body. No problems were found and it didn’t appear to go outside of the expected parameters when at our shop.

The car could have been running higher at idle due to the very cold outside temperatures. Once it would reach operating temperature, the rpm’s were similar to what they should be at idle.

Hyundai Sonata running higher at idle.
Hyundai Sonata running higher at idle

This is one of several concerns drivers have expressed lately when dropping off their vehicles. Car vibrations are another behavior some are noticing.

What causes car vibrations?

During the wintertime, we will work on a few vehicles that are shaking. It might feel like the car has a vibrating steering wheel. 

When the problem occurs can vary – maybe it’s when a motorist is heading down the road at 40 to 50 miles per hour or they’re not moving at all.

There are many potential sources behind a shaking car. These include:

  • Axles
  • Axle shafts
  • Brake rotors
  • CV shafts
  • Differential (in rare cases)
  • Drive shafts
  • Hydraulic engine mounts
  • Rims
  • Tires
  • Transmissions
  • Wheels

Brake rotors: If a vehicle is only vibrating when braking, there may be something wrong with the brake rotors.

Drive shafts: Bad universal joints (or u-joints) are an example of what can cause a drive shaft to shake. Carrier bearings could go bad, as well.

Hydraulic engine mounts: Hydraulic engine mounts that don’t have enough fluid in them could result in car vibrations.

Apprentice Technician performing wheel balance on Michelin CrossClimate 2 Tire.
Apprentice Technician performing wheel balance on Michelin CrossClimate 2 Tire

Tires: Sometimes the problem has to do with the tires. A Chevrolet Silverado was brought in for a severe shaking symptom. After checking the driveline, one of our technicians removed the front two wheels. They didn’t have the correct weight distribution. 

Transfer case: A vibrating symptom may be the result of a bad transfer case, which links the transmission and front axle.

Wheels: Winter weather sometimes hits Northern Virginia during this season, so it is possible that snow has built up on the wheels, causing vibrations.

Diagnostic testing on road manners

Performing diagnostic testing on car vibrations and other behaviors is similar to how we address noise diagnostics.

After taking notes about a driver’s concern, we inspect the tires and wheels. If the technician doesn’t see any problems, they attempt to recreate a scenario where the problem occurs.

For example, if the shaking is felt at 40 miles per hour, our technicians conduct a test drive at that speed. If the vibration happens when idling or at a traffic light, they may leave the car in park or go on a road that has traffic lights.

The process can vary based on the road manner and may include different tests to narrow down the cause. If an autoshop recommends diagnostic testing, ask them what the steps look like for your situation.

As with noise diagnostics, the more details you are able to provide about the issue and when you notice it, the better!

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Lake Ridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Winter car problems that can occur

In Vehicle Maintenance by HomeTowne Auto Repair & Tire

The frigid temperatures and inclement weather that winter brings can make severe blows to your vehicle.

Tire pressure tends to drop with drastic decreases in temperature. Icy roads might impact your suspension and wheel alignment. Weak parts that are on their final stretch of life could break.

If an item stops working at the wrong time, it could affect your safety or result in an inoperable car.

Car parts and wintertime

Here are some car parts that may be affected by the colder months (more information about winter car problems can be found below):

  • Batteries
  • Bearings
  • Belts
  • Electrical parts
  • Fluids
  • Seals
  • Windshield wipers
  • Windshield wiper motors

Battery: Many people have heard that weak batteries will fail during this time of the year. While that is true, more fail in extreme heat than during the colder months. It’s just more inconvenient when it’s cold outside and your car won’t turn on.

Bearings and seals: When it’s warm, bad bearings and seals may still work OK. During the winter, things can contract a bit and you might start noticing more problems. Leaks could occur because the lower temperatures add extra pressure to seals and they aren’t able to do their job.

Cracking drive belt on a Acura RSX.
Cracking drive belt on a Acura RSX

Belts: Belts wear out, crack, and become glazed from daily use. If there’s something wrong with a belt, you may hear it chirp more than it normally would.

Electrical components: Wintertime sometimes has an effect on electrical parts, too. This includes window motors, four-wheel drive actuators, or anything that has to do with electrical contacts. The cold weather will finish off any mediocre parts.

Brake fluid exchange on a Chevy Silverado.
Brake fluid exchange on a Chevy Silverado

Fluids: You will want to make sure that contaminants haven’t collected in your vehicle fluids (i.e brake fluid, coolant, power steering fluid, transmission fluid), which don’t flow as quickly during winter. Low fluid levels are another problem we keep an eye out for.

Windshield wipers for a Genesis G70.
Windshield wipers for a Genesis G70

Windshield wipers and wiper motors: When you’re driving through snow and ice, it forces the windshield wipers and windshield wiper motors to work harder. Windshield wiper blades can tear and the motor could stop working.

Other problems: Sand and salt that’s spread on the roads may cause a few problems, including corrosion buildup. These materials can also lead to surface rust on the exhaust as well as steering and suspension components. They could dry out boots and make rubber parts brittle, too. A lot of nicer cars have panels that protect parts of the vehicle. It’s a good idea to keep up with the panels, which can prevent corrosion from collecting underneath.

Preventing winter car problems

We aren’t able to predict all winter car problems we will experience. However, being aware of issues that can arise and any preventative maintenance your car needs could help you avoid unexpected setbacks. 

Our technicians fill out a Digital Vehicle Inspection on the vehicles they work on. If your auto repair shop looks over your vehicle during oil changes, pay attention to any recommendations they make.

Some maintenance items don’t need to be completed right away, but knowing about them allows you to plan your budget and future appointments you need to make.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Dale City, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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How to maintain your car fluids

In Vehicle Fluids, Vehicle Maintenance by HomeTowne Auto Repair & Tire

The holidays are starting to arrive and motorists are solidifying their vacation plans.

Has the auto repair shop you bring your car recommended maintenance during the past few months? Now is a good time to catch up on any needed work, especially if you’re planning to drive more than an hour down the road.

Because they are hidden underneath the hood and travel between components, car fluids tend to get forgotten. However, making sure they are at appropriate levels and replacing them when needed can extend the lifespan of many parts and prevent unwanted breakdowns.

Before embarking on any winter adventures, have an autoshop inspect the fluids. If they are low, it could indicate a leak. Fluids that appear dark may require flushes.

Car fluids: What do we check?

Checking fluids is one of the items on our courtesy inspection. Here’s what the technicians look at:

Brake fluid: We keep an eye out for dark brake fluid, but just because it’s dark doesn’t mean it’s time for a brake fluid exchange. This mileage-based service should be performed if there are contaminants and moisture in the braking system. Moisture can lead to corrosion buildup and the deterioration of brake parts.

Green brake fluid on a Honda Pilot.
Green brake fluid on a Honda Pilot

Coolant: Dark and discolored coolant are some problems our technicians watch for. It’s also important that the fluid isn’t acidic. The PH level can be checked using a test strip. Coolant fluid exchanges replace coolant, which eventually breaks down. Sludge, rust and scale are cleaned out, as well.

Low coolant on a Ford Focus.
Low coolant on a Ford Focus

Oil: Oil is another fluid that we want to check before sending drivers on their way. It’s important that a car is running on enough oil and that oil changes are conducted on a regular basis. Oil lubricates certain components and different parts run off oil pressure. Having too little oil can lead to engine damage. 

Transmission fluid: During courtesy inspections, our technicians make sure the transmission fluid isn’t dark or smells burnt. If a driver has noticed they are having some trouble switching gear, it can point to a transmission problem. Transmission fluid exchanges remove contaminants and put in new transmission fluid, which keeps items lubricated.

Power steering fluid: Your vehicle might be in need of a power steering fluid exchange if the fluid is dark and the steering feels loose. Many parts come in contact with power steering fluid. With regular flushes, you can protect these components and maintain smooth, firm steering.

Dark power steering fluid on a Jeep Grand Cherokee.
Dark power steering fluid on a Jeep Grand Cherokee

Windshield washer fluid: There should be enough windshield washer fluid to properly clear your windshield. A good temperature protection level is also needed, otherwise the fluid can freeze.

Other fluid maintenance tips

When cold temperatures set in, car fluids don’t flow as fast. That’s why you want them to have as little contamination as possible.

Cold weather tip: We realize the holiday season is busy for many people. Before heading out to complete errands or enjoy the festivities, make sure you give your vehicle a few minutes to run at idle before putting it in drive or reverse. This allows the oil and transmission fluid to flow.

With the way the engines are designed, it allows the oil pressure to get to where it needs to be and helps you avoid undue wear.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Dumfries, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Is your windshield winter ready?

In Vehicle Maintenance by HomeTowne Auto Repair & Tire

The colder months are steadily approaching Northern Virginia. 

As the leaves and outside temperatures begin to fall, make sure to set aside time to prepare your vehicle.

Just having an automotive professional look it over can make you aware of issues and provide you with peace of mind.

If your car will be due for an oil change or other maintenance soon, ask if a technician can check out the battery, tires, brakes, fluids and belts too.

It’s also a good idea to check out the windshield. Here are some ways you can confirm that it’s winter ready.

Windshield problems

When preparing your vehicle for wintertime, you will want to look for any windshield problems:

Cracks in the windshield: Are there any cracks obscuring your vision? Not only can they be a nuisance, windshield cracks could get bigger overtime. A car won’t pass the Virginia State Inspection if there is a crack that goes across the windshield or a star crack is larger than 1 and a half inches around. Try reaching out to your insurance company and see if they offer windshield coverage.

Windshield washer fluid reservoir leaking on a Honda CR-Z.
Windshield washer fluid reservoir leaking on a Honda CR-Z

Low windshield washer fluid: Before heading into the holidays, make sure your vehicle has plenty of windshield washer fluid to wash away any salt or dirt that hits your windshield. If you notice that you’re topping off the fluid frequently, the reservoir might be leaking.

Sprayers not working: Sometimes, you have enough windshield washer fluid but the sprayers aren’t working. This problem can be caused by broken lines, clogged and broken nozzles, and a bad windshield washer pump.

Torn windshield wipers: During the winter, Northern Virginia may receive a fair amount of rain and the occasional snowfall. Windshield wiper blades should be inspected regularly for any tearing. Their lifespan depends on driving conditions and behaviors. If your windshield wipers aren’t clearing the windshield, have them replaced.

Toyota Highlander worn windshield wiper blade.
Worn windshield wiper blade on a Toyota Highlander

Malfunctioning defroster: For your vehicle to be winter ready, it’s important that the defroster is able to clear out the windshield and windows properly, especially if we see any ice. If the defroster doesn’t seem to be doing its job, there could be a problem with the a/c system.

Other ways to get your car winter ready

Sometimes, windshield components malfunction and need to be checked out or replaced. However, there are also a few day-to-day tips that can help you this winter.

On top of confirming that your car has enough washer fluid and all windshield components are functioning, make sure the fluid offers a good temperature protection level. If it doesn’t, it could freeze in the reservoir and the water pump.

Helpful tip: Using a product like RainX on your windshield can help improve your visibility while it’s raining and snowing. Usually, snow and ice will slide right off when vehicles that have this coating.

Cleaning the inside of the windshield once a month is another way you can continue to see well. This prevents it from fogging up.

If you do need to replace your windshield due to cracks, see if your vehicle requires an Advanced Driver-Assistance Systems (ADAS) reset.

Whatever the winter has in store, maintaining a clear windshield will help you navigate the roads safely.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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What can cause sticking brakes on your car

In Brakes by HomeTowne Auto Repair & Tire

Do your car brakes feel like they are sticking?

A Cadillac XTS driver was experiencing this problem. When it was brought into our shop, our technician saw that the driver side rear wheel wasn’t spinning. The brakes would stick when they were cold and hot.

Sticking brakes can feel like you’re pressing the brake pedal even though you’re not.

When they’re hot, you may notice a vibration or – eventually – a pulsation.

There are a few possible problems that could cause brakes to stick

  • Slide pins not moving
  • Seized brake caliper
  • Parking brake mechanism sticking

We recommended brake diagnostics to track down the exact reason and see if it was causing other issues.

What problems can lead to sticking brakes?

When working on this type of brake repair, our technicians start with the brake fluid.

We inspect and recommend replacing brake fluid when opening the brake lines. This fluid is very corrosive – if brake fluid is on an item it could easily take off the paint.

With the transfer of heat and moisture, the fluid can break down the inside of the braking system if you don’t service it regularly.

Old brake calipers for a Cadillac XTS.
Old brake calipers for a Cadillac XTS

If a customer mentions that their car has sticking brakes, we would want to make sure the slide pins move. It’s also important to confirm that the brake caliper pushes down and the parking brake mechanism isn’t stuck.

There are a couple different kinds of parking brakes. Some operate with the caliper and others are actuated from the inside with brake shoes. They both have an arm mechanism and work similarly.

Brake repair on the Cadillac XTS

On the Cadillac XTS, the electric parking brake was operating correctly and the slide pins were free. This helped us track down the reason behind the brake problem – a caliper that was seizing up.

If this part doesn’t move freely, it gets stuck in one position and has to be moved. The pistons on the Cadillac’s caliper wouldn’t move back and forth.

When replacing brake calipers, we will do it in pairs. The other caliper was working fine. However, if you take a new caliper and an old caliper, one will react faster than the other.

Old brake hoses on a Cadillac XTS.
Old brake hoses on a Cadillac XTS

The brake hoses were changed, as well. You have a soft rubber on the inside of the hose that can deteriorate. We replaced both the calipers and the hoses as a set to avoid a repeat problem.

Now this car has fresh parts, new fluid, and a healthy braking system.

Taking care of your brakes

Staying up-to-date on brake maintenance keeps the system running as it was designed and prevents premature wear among parts.

Brake fluid exchanges are suggested every 30,000 miles, depending on the vehicle and the manufacturer’s recommendations.

Brake hoses, brake lines, brake pads and rotors, brake hardware and other components should be replaced as needed.

Our technicians perform digital inspections to let customers know how different parts of the vehicle are looking and share any recommended services.

If you experience any braking problems while driving, have that checked out by a nearby auto repair shop. That includes sticking brakes, hard brake pedals, brake pedals going to the floor, and shaking in the seat or steering wheel when braking.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Lake Ridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Why did my car’s ABS light come on?

In Automotive Diagnostics by HomeTowne Auto Repair & Tire

Whether you’re turning, stopping or accelerating, a vehicle’s anti-lock braking system (ABS) is operating, unnoticed.

It makes sure that the tires are moving at the same relative speed, based on the vehicle’s actions. For example, if you’re turning left to drive around a corner, the right wheels are going faster than the left ones. 

The computer takes that data and sends it to the power control module (PCM) or engine control module (ECM). Information is constantly provided in real time, so if the computer needs to take over and engage the ABS to keep your wheels from locking up it will do that. 

How the ABS system works

Before we go into what triggers the ABS light, we want to talk more about how the system operates.

On most cars that use four-wheel ABS, each wheel has a sensor. The sensor doesn’t just know how fast the wheel is spinning. The magnetic piece picks up high points on a tone ring that’s located in the bearing, on the axle, or on a nearby component that rotates.

Let’s say all four wheels on a vehicle are going 40 miles an hour and the car notices the brake was applied and one of the tire speeds drops down to 22 miles an hour. The ABS has a modulator valve that pulses the brake fluid, freeing up the wheel and preventing it from locking up.

What causes the ABS light to turn on?

The ABS light can appear on your dashboard for many reasons. These include:

  • Low brake fluid
  • Bad sensors
  • Flaws in the main computer
Low brake fluid on a Honda Pilot.
Low brake fluid on a Honda Pilot

You may see this symbol when the car says it doesn’t have enough information to make a decision. If you step on the gas at a traffic light and 3 wheels are traveling at 30 miles per hour while 1 is going 0, the car will realize something is wrong and trigger the light.

A vehicle needs to perform certain calculations to determine if the information received is possible. Once it notices that some part of the system is not plausible or has an open circuit, it’s going to trigger the light every single time.

You can have an erratic signal where the ABS system is engaging when it’s not supposed to. That could mean you have a damaged tone ring or an issue with the component that sends information from the sensor.

Problems outside of the ABS can play a role, too. If your traction control system isn’t working, it’s also going to shut down the ABS system.

Connection problems can also lead to the icon appearing.

ABS sensors rarely get manipulated or move. They will sit in one spot for a really long time. We’ve seen corrosion build up so much that it pushes the sensor away from the tone ring. The light turns on because it’s an implausible situation for the computer – as if it’s saying, “I know we’re moving, but I’m barely picking up on this tone ring. Something’s wrong.”

Diagnosing ABS problems

We begin ABS diagnostics by making sure the vehicle has proper battery voltage, good battery connections, and clean terminals.

Master Technician using the scan tool on a Toyota RAV4.
Master Technician using the scan tool on a Toyota RAV4

The computer is scanned while our technicians are checking these items and making sure no fuses are blown.

Any codes that appear act as a starting point. From there, the diagnostic process can branch out into various directions.

After receiving codes, we see if there’s anything implausible or multiple problems are occurring.

If your car’s ABS light has turned on, bring it by a nearby autoshop to make sure that the ABS system is working the way it was designed. 

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Dale City, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.

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Coolant and refrigerant: What’s the difference?

In Vehicle Fluids by HomeTowne Auto Repair & Tire

Cars can be complicated, and it’s easy to be confused about services and terms you hear when visiting an auto repair shop.

Sometimes, drivers may mix up fluids found in a vehicle.

Coolant and refrigerant are a couple of examples. These two fluids are used in different systems. 

An automotive professional may mention “coolant” when talking about a car’s cooling system. This fluid helps prevent the engine from overheating.

Meanwhile, refrigerant is associated with the air conditioning system and keeps you feeling cool during those hot summer days.

How the cooling system and a/c system work

The cooling and a/c systems both operate in a circle. However, the parts and process differ.

Cooling systems feature a thermostat that acts like a door and remains closed until the engine block reaches a certain temperature. Then, it slowly opens. The water pump pushes coolant through the radiator. This fluid continues to travel into the heater core and back to the engine block.

As the thermostat opens up, more coolant is able to get into the radiator and keep the engine block at an even temperature. 

On the a/c system, you have a compressor that creates pressure. Pressurized lines go into the evaporator, which has larger tubes.

When the refrigerant goes from a tight, high compression into a loose area, it gets very cold.

Like the thermostat, the expansion valve opens and closes based on temperature.

After the refrigerant makes its way through the evaporator, it runs through the condenser, which sits next by the radiator. The air conditioning condenser turns the gas into a liquid. Then, the refrigerant goes back to the compressor.

Looking for coolant and refrigerant leaks

Leaks can occasionally occur in the air conditioning and cooling systems. When they do, we start our investigation with a visual inspection.

Using ultraviolet dye to locate air conditioning leaks on an Acura TL.
Using ultraviolet dye to locate air conditioning leaks on an Acura TL

If a/c leaks are present and can’t be located, our technicians receive help from a machine and ultraviolet dye. The a/c machine enables them to confirm there is a leak through a vacuuming process. We inject dye and oil before recharging the a/c system.

The customer will then drive their car for a certain amount of time and return to the shop so we can find the dye. It’s a good idea to bring it back after a week, even if the air conditioning system is still working. However, it could take months to spot the leak.

There is no tracer dye yet for 1234yf systems. In these cases, we inject the system with nitrogen and use a sniffer that smells gas.

Coolant leaking from heater hoses on an Infiniti M37.
Coolant leaking from heater hoses on an Infiniti M37

We can follow a couple of paths to track down coolant leaks. After looking the vehicle over, we pressurize the system using a coolant pressure tester. Two or three times of what the system’s pressure would be is applied, prompting any external leaks to drip.  

In cases where a system doesn’t have any external leaks but is experiencing coolant loss, we’ll look for coolant transferring into other systems. Different tests, such as a block test or hydrocarbon test, may be performed.

Kinds of coolant and refrigerant

There are different types of coolant and refrigerant. 

Engine metal and coolant requirements differ between Asian vehicles and those made in the United States, for example. European cars also have a specific kind of coolant.

R-134a air conditioning machine.
R-134a air conditioning machine.

R-12 is the refrigerant needed on cars that were made before 1995 and 1996. After that, R-134a started to be used. R-1234yf can be found on more recent vehicles. More information about AC repair and maintenance can be found in this article we wrote.

Knowing the coolant and refrigerant your car takes could prevent damage and allow these systems to run as designed.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located near Lake Ridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.