Have you ever had an experience like this in St. Peter, MN? You drive through the one of those automatic car washes. When you get to the end, where the dryer is blowing, your Check Engine light starts flashing!

You fear the worst, but within a block or two, the light stops flashing, but stays on. By the next day, the light is off.

You wonder; “What was going on?” Well, it’s actually a good lesson in how the Check Engine light works.

Your air intake system has a sensor that measures how much air is coming through it. When you went under the high-speed dryer, all that air was blasting past the sensor. Your engine computer was saying, there shouldn’t be that much air when the engine is just idling. Something’s wrong. Whatever’s wrong could cause some serious engine damage.

Warning, warning! It flashes the Check Engine light to alert you to take immediate action.

It stopped flashing because once you were out from under the dryer, the airflow returned to normal. Now the engine control computer says the danger is past, but I’m still concerned, I’ll keep this light on for now.

Then the Check Engine light goes off in a day or two.

The condition never did recur, so the computer says whatever it was, it’s gone now. The danger is past, I’ll turn that light off.

Now a flashing Check Engine light is serious. You need to get it into Autotronics of St. Peter as soon as possible. But if it stops flashing you can wait a few days, so you have time to see if the problem will clear itself or if you need to get it checked. How does the computer know when to clear itself?

Think of it this way. The engine control computer is the brain that can make adjustments to manage the engine. Things like alter the air-to- fuel mix, spark advance and so on. The computer relies on a series of sensors to get the information it needs to make decisions on what to do.

The computer knows what readings are in a normal range for various conditions. Get out of range, and it logs a trouble code and lights up the Check Engine warning.

The computer will then try to make adjustments if it can. If the computer can’t compensate for the problem, the Check Engine light stays on.

The computer logs a trouble code. Some people think the code will tell the technician exactly what’s wrong.

Actually, the code will tell the technician what sensor reading is out of parameters. It can’t really tell him why, because there could be any number of causes.

Let’s say you’re feeling hot. You get your heat sensor out – a thermometer – put it under our tongue and in a minute or two you learn that you have a fever of 104 degrees F (40 degrees C).

You know your symptom – a fever – but you don’t know what’s causing it. Is it the flu, a sinus infection or appendicitis?

You need more information than just that one sensor reading. But it does give you a place to start and narrows down the possible problems.

There are reports on the internet telling you that you can just go down to an auto parts store and get them to read your trouble code or buy a cheap scan tool to do it yourself.

There are two problems with that. First, the computer stores some trouble codes in short term memory and some in permanent memory. Each manufacturer’s computer stores generic trouble codes, but they also store codes that are specific to their brand.

A cheap, generic scan tool, like you can buy online or that the auto parts store uses, doesn’t have the ability to retrieve long-term storage or manufacturer specific codes. Your St. Peter, MN, service center has spent a lot of money on high-end scan tools and software to do a deep retrieval of information from your engine control computer.

The second problem is that once you’ve got the information, do you know what to do with it? For example, a very common trouble code comes up when the reading on the oxygen sensor is out of whack.

So the common solution is for the auto parts store to sell you a new oxygen sensor — which is not cheap — and send you off on your way. Now your oxygen sensor may indeed have been bad and needed replacing. But the error code could have come from any of a dozen of other problems.

How do you know the right solution? Back to the fever analogy, do you need surgery or an aspirin? Leave it to the pros at Autotronics of St. Peter. Give us a call and let us help you resolve your check engine light issue.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

Today we’re going to talk about on-board diagnostics and the questions we hear from folks around St. Peter, MN, who need answers about diagnostic services. They want to know what diagnostics are, what’s involved and what the benefits are. They really want to understand the value of diagnostic scans by a trained technician in St. Peter.

These are valid concerns. If you don’t understand something it’s really hard to know its value. Let’s start with some history.

Since 1996, all cars and light trucks in St. Peter, MN, have been required to use a standardized diagnostic system to help repair technicians determine what’s wrong with your vehicle. The diagnostic system works with the vehicle’s Engine Control Module – the computer that controls many engine functions.

The computer monitors dozens of components and processes. Depending on what the sensors read, the computer will make adjustments to compensate for conditions and minor problems. When there is a condition that it can’t adjust for, the computer will turn on the Check Engine light.

It is also called the ‘service engine soon’ light on some vehicles. The warning light signals you to get into your local service center so that the trouble code can be read and the problem can be fixed. Your service center will have a scan tool and powerful software that will help the technician diagnose the problem.

If you’ve searched for Check Engine light on the internet, you may have seen that you can buy an inexpensive scanner or go to an auto parts store to have the trouble code read to tell you exactly what’s wrong.

That’s a common myth. The code itself doesn’t tell you what’s broken. It starts you looking in the right place. It tells you what engine parameter is out of range – but it won’t tell you what’s wrong or how to fix it.

Let’s say you think your daughter has a fever. You take her temperature and it reads 102 degrees F/38.9 degrees C. You’ve confirmed a fever, but you don’t know what’s causing it. Is it a 24 hour flu, an infection, appendicitis or leukemia? A fever is a symptom of all of these medical problems, but it takes a skilled physician’s examination and additional diagnostic tests to find out what is actually causing the fever.

An example of a trouble code could be: P0133, which reads ‘Bank 1 sensor 1 circuit slow response.’ This means that the front oxygen sensor has a slow response time to changes in the air-fuel mix. If that’s all you knew about cars, you would think your oxygen sensor was broken and would replace it. Now, it could be the oxygen sensor – but it could also be a bad or contaminated airflow sensor, exhaust leak, electrical problem, an intake manifold leak or any of a number of other things.

You can imagine a lot of oxygen sensors have been replaced because of that code. So the on-board diagnostics point the way to where the trouble lies, but it takes some skill and high-tech equipment to actually pinpoint the problem. The cheap scan tools that a consumer can buy do not have the ability to retrieve some of the operating history that’s stored in the engine control computer. That history’s very helpful in diagnosing the problem. Service centers like Autotronics of St. Peter invest a lot of money in high-end diagnostic tools to help solve the mystery and get you back on the road as soon as possible without replacing a lot of parts that don’t need replacing.

So, on-board diagnostics provide a powerful starting place for a highly-trained, well-equipped technician to get to the bottom of your problem. When your Check Engine light comes on, get it checked at Autotronics of St. Peter. If the light burns steadily – don’t panic. Get in to Autotronics of St. Peter soon to have the engine scanned. A flashing Check Engine light means that there is a severe engine problem. Get in as soon as you can – waiting too long can lead to very expensive damage.

And try to not drive at high speed or tow or haul heavy loads with a flashing Check Engine light.

Make an appointment with Autotronics of St. Peter to have your on board diagnostics analyzed.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com

Have you ever thought about all the little things we do to keep our lives running smoothly – like vacuuming? It makes a room feel fresher and more comfortable. We may not consider that we’re also prolonging the life of the carpet by keeping it clean. But St. Peter drivers don’t always extend those good habits into the garage. Our vehicles need regular maintenance just like our rugs need vacuuming. We may not notice a difference in the feel or appearance of the vehicle, but just as cleaning a carpet carries the hidden reward of prolonging its life, maintaining our vehicles incurs a hidden reward that becomes noticeable at St. Peter gas stations.

When it comes to reduced fuel economy, there are two culprits: increased friction and inefficient fuel combustion. That means that anything St. Peter drivers can do to decrease friction and increase the efficiency of their engines will translate to savings on fuel. Friction increases the amount of energy it takes to move something. So if we can reduce friction, we can decrease the amount of fuel it takes to run our vehicles. Engine oil is usually at the heart of friction problems in an engine. Too little oil means parts are not getting lubricated, which increases friction; dirty oil doesn’t lubricate as well as clean oil. So one secret to good fuel efficiency is to stay on top of oil changes. Don’t skip them and don’t procrastinate. The same auto advice applies to transmission fluid. Keep it full and keep it clean, and your vehicle will run with less friction and better fuel economy.

If your tires are underinflated, it increases the friction between the tire and the road. Again, there is increased drag, and it takes more fuel to move your vehicle. St. Peter drivers should check their tire pressure every month and keep their tires properly inflated.

Alignment and brake problems can also increase friction. Besides saving fuel, keeping these systems in good repair has the added benefit of saving you on tires and brake pads. These items wear out more quickly when the alignment is off or when the brake system isn’t in good working order. Talk to your friendly and knowledgeable service advisor at Autotronics of St. Peter.

The second culprit that stealthily steals our gas is inefficient fuel combustion. It depends on the engine getting the right amount of clean fuel to the right place with the right pressure at the right time in the right pattern. The key to peak engine performance is to keep the fuel system clean. Varnish and gum can build up in a fuel system, which will interfere with the fuel injectors. The fuel injectors are responsible for all those “rights” we spoke of. If they’re dirty, amounts, timing, pressure and spray patterns can all get out of whack. The result? Reduced fuel efficiency. A fuel system cleaning at Autotronics of St. Peter in St. Peter can get your injectors back on track, improving performance and efficiency.

There are a few other maintenance items that can improve your fuel economy. One is to replace your PCV valve when it gets sticky. This valve allows unburned fuel in your engine exhaust to return to the engine. St. Peter drivers can also replace worn spark plugs and dirty fuel filters. A well-maintained vehicle will require fewer repairs and save at St. Peter gas pumps.

Autotronics of St. Peter
111 Jefferson Avenue
St. Peter, MN 56082
507.934.9290
http://autotronicsstpeter.com