Aveley Garage & M.O.T. Centre

Why Are Car Diagnostic Tests Important?

People have their annual check-ups from their physicians to check their health. It’s the same thing with cars. Regular diagnostic tests are needed to detect minor issues with the car before they turn into bigger problems that require expensive repairs. As a car owner, the last thing you want is to get stranded on the side of the road after a breakdown.

However, many car owners in the UK still think that they only need car diagnostics when their cars’ check engine light comes on. These diagnostic tests are so much more than that, which we will talk about in this post. Continue reading about the benefits of taking a proactive approach to car maintenance.

Car Diagnostic Test: What Is It and How Does It Work?

In terms of technological advances, the automotive sector has benefited a great deal from technology over the past few decades. One of the most beneficial advancements that make the lives of technicians and consumers more convenient is the computerisation of car components.

With specialised software programs, it’s now possible and easier for car diagnostic tools to point to problem areas in a car’s engine or elsewhere. That’s all thanks to built-in processors, microchips, and sensors.

As you may already know, vehicles today are designed with an internal computer that is operating, recording, and monitoring all major systems and components. These internal computers even scan notifications from the vehicle manufacturer and check a car’s performance history.

Using an advanced computerised tool, a car technician is able to connect to the car. After establishing a connection with the car’s internal computer, the technician can review the codes to read the notifications. This is how a technician identifies where the car is experiencing difficulties.


What a Diagnostic Test Tells You?

A universal interface system called On-Board Diagnostics or OBD II provides car manufacturers and technicians with information from areas monitored by a vehicle’s internal computer. OBD II monitors all sorts of systems, including:

⦁ Engine
⦁ Cooling systems
⦁ Brakes
⦁ Transmissions
⦁ Exhaust systems

A car diagnostic test will provide details on the codes stored from various areas on the car. From the ignition timing (whether ignition coils are firing accurately), fuel injector performance, engine RPMs, and the amount of build-up in the combustion chamber, these details will be delivered in real-time. The OBD has codes that correspond to a certain part of the car, which communicate the error detected in these parts.

There is a caveat when it comes to car diagnostics. While the advances in these internal auto computers have been integral in repair work, the diagnostic does not really pinpoint the exact cause of the trouble. OBD II indicates to the car technicians which major component is operating outside of the normal range and where to begin testing.

Some people think that OBD II reports the exact component responsible for the error. But with knowledgeable and certified car technicians performing diagnostics, the problem is identified and resolved.


What Are the Advantages of Car Diagnostic Tests?

Car diagnostic tests are critical to the proper repair of any type of vehicle, whether it be a semi-truck or trailer. These diagnostic tests are important for getting a vehicle fixed with as little downtime as possible and getting it back on the road safely. Doing these tests on a private car, truck, or trailer can help motorists in a number of ways.

Diagnostic tests are important because of these primary reasons:


They identify the car’s problem

As we have previously mentioned, diagnostic tests will not tell car technicians exactly what is wrong with the vehicle. By running the fault codes stored in the car’s internal computer, technicians can narrow down the issue so they can figure out what component is not functioning properly.


They are a cost-effective method

Identifying the problem within a car’s operating system would take a lot of time, energy, and money without the use of vehicle diagnostics. There could be many unseen car parts that are malfunctioning, but running the codes through a diagnostic test helps make the problems more apparent. This saves you money on repairs.

Today, car diagnostic tests are a preferred method among motorists and technicians alike. This is because of the time and money they can save. Before auto internal computers were a thing, vehicle owners would have to describe in detail what’s happening to their cars.

As technicians begin the seemingly drawn-out process of testing various parts and components to identify the trouble, vehicle owners stand by idly. This is very time-consuming and also costly. Diagnostic tests make everything quicker and smoother.


They prevent major problems

In most cases, small problems like strange noises that go unnoticed for a while eventually turn into much bigger problems that require expensive repairs and long downtime. These problems can also lead to potentially dangerous situations down the road.

Diagnostic tests have the ability to catch minor issues early on, giving you time to have them fixed before they turn into major problems.


What Issues Do These Tests Identify?

Car diagnostics can identify several areas of concern in most vehicles. These include the following:

⦁ Air and coolant temperature
⦁ Camshaft position
⦁ Crankshaft issues
⦁ Engine management problems
⦁ Engine RPM levels
⦁ Engine timing problems
⦁ Issues with the engine
⦁ Fuel injector performance
⦁ Problems with brakes

By running the codes, mechanics and car technicians can easily identify these vehicle malfunctions and fix them more quickly.


When Should These Tests Be Done?

A lot of vehicle owners think that diagnostic tests are unnecessary and should only be done when the check engine light comes. Some owners get it done only when they visit a mechanic, hoping that their car is in perfect condition. There are other circumstances in which these tests are important, aside from when the check engine light goes on.

You can get these tests done before your vehicle’s scheduled MOT. If you notice even small things wrong with your vehicle, then you should have diagnostic tests done. This could be something as obvious as a strange noise or a minor change in handling.

It’s best to be proactive when it comes to your car. Even if your check engine light is not on, there could be small unseen problems in your vehicle. Having a skilled technician or mechanic check on your vehicle means you’re able to catch these problems early on and resolve them.

If possible, have your vehicle tested every year. Like other things you have to check on a routine basis—oil, filters, belts, spark plugs—diagnostic tests should be included on your list. Your vehicle will thank you for it and you will be equally grateful for doing proactive maintenance checks.


How Long Do These Tests Take?

Auto diagnostic tests should only take a few minutes to complete. Every test starts with check engine light code reading (also known as OBD II codes reading) where the technician checks the codes for notifications if there is any issue. The technician simply plugs in a car diagnostic scanner to read the codes that indicate the problem.

After getting the trouble codes, the technician then carries out some investigative work to get a more accurate picture of what part is functioning incorrectly. Depending on the trouble code that appeared, the technician decides how best to fix the issue at hand. If you bring in your vehicle for a diagnostic test at an auto shop, expect to wait a little bit before the test.

You can stay to discuss what issues were found and what steps to take to fix them. Generally, you can expect to spend at least an hour to discuss these. A reasonable estimate would be 2-3 hours.


How Much Do These Tests Cost?

The cost of a vehicle diagnostic test in the UK can vary greatly depending on the vehicle’s brand, model, engine, and its issues. Another factor is whether you live in a big city or a small one. You can expect to pay anywhere between £46.92 and £50.30 for a diagnostic test in dealer shops. (That’s the average price excluding any other repairs that need to be done).

Some shops claim they provide free car diagnostic services. However, be judicious as they may charge a hidden fee. If you check in the details about the services offered by an auto shop, you may see only the first part: engine light code pull service for free.

But then, they will most likely conduct further investigations based on the code they got. They might continue to bill you for the labour, giving you an outstanding fee of £55 to pay. Some places may recommend you to buy a scanner if you bring in your car for a test.


How to Find the Right Mechanic to Run a Diagnostic Test?

It’s easy for a bad mechanic to oversee things and tell you your vehicle is in tip-top shape when it’s not. Some mechanics might take advantage of someone’s lack of knowledge of vehicles or experience. It doesn’t feel good to be ripped off, so you want to make sure that you turn to the right people when it comes to your vehicle’s diagnostic test.

Here are some helpful tips to help you choose the right mechanic to run a test:


Ask around

In today’s world of angry online reviews, it can be a challenge to get an accurate picture of how good a business is. You can drop the idea of searching on the internet. Instead, call your family, friends, and co-workers and ask if they have any recommendations.

Your family and best mates will be honest about any stellar services and overpriced repairs. Think of the good mechanics in your area; they know the power of word-of-mouth recommendations and will work hard to earn them.


Know the basics of your vehicle

One way to protect yourself is by having some idea of how your car operates. You can refer to your owner’s manual to understand the basics of your car. This may sound boring, but this will set you up with the knowledge you need to identify which problems can be fixed easily on your own and those that need professional attention.

By knowing the basics of your car, you can understand what your mechanic tells you. This could protect you from unnecessary expenses.


Look up the cost of relevant car parts

After taking your car to the mechanic, don’t forget to ask for a copy of all receipts (car parts and labour included). You can check with a car dealership or an online retailer if the cost of parts on the receipts are similar. If not, ask your mechanic for a refund. You can also ask the mechanic to keep any old parts to avoid additional costs.


Can I Do a Diagnostic Test at Home?

The thing about vehicle diagnostic tests is that they actually do not magically show what might be faulty. A vehicle diagnostic test consists of two steps: Diagnostic Trouble Codes (DTC) Reading and interpreting the codes for further investigation. These steps could be done at home without professional knowledge.


Diagnostic Trouble Codes (DTC) Reading

To do this, you need an OBD II scanner. This tool lets you read the trouble codes or check engine light codes from your vehicle’s internal computer. With this scanner, you will have a list of trouble codes that indicate where the issue may come from.

While it doesn’t tell you what the specific problem is, you can have an idea of what the problem may be and how you can diagnose it. There are many OBD II scanners in the market today. You can get one with smart Bluetooth connectivity as it’s easy to use and install.


Interpreting the trouble codes

Most scanners available today come with a guide that gives information about what the codes mean. Some guides list the codes with their possible causes and simple diagnostic steps you can take to identify what the problem might be.


In Summary

Car diagnostics is crucial for your vehicle health. It is highly recommended that you run diagnostic tests regularly to prevent minor issues from becoming bigger problems. A hassle-free choice is to bring your vehicle to a trusted mechanic.

If you feel that something is off with your vehicle, don’t hesitate to consult our team here at Aveley Garage and MOT Centre today.


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