What is Car Diagnostic Test and How to Do it Yourself

Table of Contents

• what is car diagnostic test? 
• What Parts of a Car Are Tested?
• How long does a car diagnostic take? 
• car diagnostic test cost. 
• How to do a diagnostic test on a car? 
• Benefits of Car Diagnostic Test. 

The vast majority of modern vehicles are more computerized than ever before, and truth be told, that's a good thing. In fact, this Computerization allows cars to be thoroughly checked with self running diagnostic tests to keep your vehicle in optimal working order. These tests can scan components and a car integrated system for errors or malfunctions before they become truly dangerous. 

What is Car Diagnostic Test

Car diagnostic tests is a digital analysis of your car's various computer systems and components. Modern vehicles are much more digitized than people may be aware of. Specialized software works whenever your car's engine is powered on to monitor various features and create data reports that can then be collected and analyzed during a car diagnostic test. 

Computerization of the car's components. Using specialized software, car diagnostic tools quickly and accurately point to problem areas in a car's engine or elsewhere, thanks to built-in processors, microchips and sensors. 

Car diagnostic tests scan your car's components and systems to check for issue with components like the engine, transmission, oil tank, throttle, any many more. 

Because car diagnostic teat require specific devices and expertise to read correctly, most tests are performed with mechanics or at dealer shops. However, you can also perform a car diagnostic test at home if you have the proper knowledge and equipment. 

What Parts of a Car Are Tested?

Diagnostic tests can reveal problems within a car's engine, transmission, exhaust system, brakes, and other major components, as well as performed test on issues like fuel injector, air flow and coolant, ignition coils, throttle, spark plug and so on. 

Why is Car Diagnostic Test Important? 

Having a diagnostic test run before having a car repair performed by trial and error will actually save you time and money. Otherwise, it could take hours, even days, for mechanic to find out what's wrong with your vehicle. 

They could also end up making repairs that really aren't needed in an attempt to make it run better. This trial and error method can end up costing you a lot of money than actually paying for a diagnostic test before beginning car repair. The test helps the mechanic identify a problem quickly and speeds up the repair process. 

How Long Does a Car Diagnostic Take? 

The diagnostic test can pinpoint exactly what is wrong. Your mechanic can then be assured of knowing exactly what needs to be repaired, and you are able to make an informed decision as to whether the problem needs to be taken care of immediately or if it can wait a while. 

A standard diagnostic tests can take about 1 hr to an 1hr and a half. Of course, more complicated issues that require further diagnostic and where components must be removed for access or testing can take 2-3 hours; depending on the severity of the issue or multiple underlying issues.

If the issue is complicated, the mechanic may have to remove a few components of your car to access and further testing. Expect your car to be tied up for two or three hours in those instances. 

Car Diagnostic Test Cost. 

Those pesky trouble codes can get out of hand quickly and should be handled quickly also.  The scan itself should be around $100 but can range from $20 to $400. Depending on the problem and the mechanic you hire, solving the problem can cost even more. 

How To Do a Diagnostic Test On a Car

Step 1:  Diagnostic Trouble Codes (DTC)  Reading

A car diagnostic test always starts with reading the diagnostic trouble codes, AKA Onboard Diagnostic Codes (OBD codes). The onboard diagnostic system was introduced and made mandatory for all vehicles sold in the United States since 1996, setting up a trouble code for manual of all self -diagnostic results. Thus, for all cats sold after 1996, you can use a standard OBD2 scanner / reader to do the car diagnostic test. 

With the OBD2 scanner, you can read the diagnostic trouble codes/check engine light codes from the vehicle computer, and have a list of codes that indicates where the problems may come from. It doesn't tell you what the problem is specifically, but you can get information about what the issue might be, and how to diagnose and fix it. 

Step 2:  Interpreting The Codes And Further Investigation

With the list of code, now what you can do is to know what they mean and how to diagnose what the problem might be. 

For example,  a code P0442 indicate evaporative emission control system leak detected small leak. The code has possible symptoms, possible causes, and several steps of simple diagnosis that you can do yourself. The code can be triggered because of a loose gap cap or a broken EVAP line that might cost $20-$80 to repair and replace. The actions to take varies depending on the code itself, or the other code. 

For some Bluetooth OBD2 scanner, the app bundled with three code reader will give you information about the codes. Or if you have a traditional elm 327 or a wired tool which will not show the explanation of the codes, you will have to search for the explanation online. 

Benefits of Car Diagnostic Tests. 

1. Modern vehicles have the added benefits of fault codes which is stored on the car onboard memory for easily diagnosing the problem of the car. 

2. Diagnostic testing is the most cost-effective and efficient way of diagnosing a problem in your car. 

3. Diagnostic is an important function in computer systems, both for manual repair and also automatic reconfiguration in fault tolerant systems. A fault may cause the system to violate it requirements I.e to fail. 

4. Saves Money

 A diagnostic check also saves money. Not only does it save labor fees because the test is quick to find the problem, but it also saves repair costs. The test identify failed or falling components or system which means it can catch problems before they actually become a real trouble. Replacing one part instead of an entire systems save you money in the end, which is why diagnostic are used so frequently in auto care. 

5. Pinpoint a problem

As opposed to guessing what  the problem might be, an electrical system diagnostic check pinpoint the exact issue. When hooked up to three vehicle onboard computer, the test checks all systems and return data auto technicians use to solve problems. This test uses error codes to identify what is wrong such as returning an error code that the spark plugs needs to be replaced. 

6. Track Fuel Consumption

Professional automotive diagnostic software can check the average fuel consumption of a vehicle. Many people look for the best fuel economy to save money and also help the planet reduce pollution cause by carbon footprint. 

The car diagnostic software test the fuel consumption for people who are on tight budget enhancing them to save money on gas in return.  All so some car dealership let you test drive a car to use the diagnostic software for gas mileage. 

7. Help with Used-Car purchase

A vehicle diagnostic check is a good idea if you want to buy a used car. The diagnostic test should be part of a full vehicle inspection to make sure that there aren't any underlying issues invisible to the naked eye. Electrical trouble rarely shows itself until it's too late, such as dead battery. You want to make sure that the used vehicle you purchase doesn't break down a few weeks later due to electrical system failure.