What is engine diagnostics and what is it showing?


Picture this: you are driving your car, and suddenly you see dashboard warning lights popping up, and you don’t know what the issue is. You begin to wonder if it’s safe to keep on driving or if you should stop and inspect your vehicle.

Perhaps this has already happened to you. Or it is yet to happen. In any way, it is good to be informed about how to avoid such scenarios, and how to ensure your car is well maintained. The solution here is called engine diagnostics, and in this article, we will learn more about it.

How Engine Diagnostics Work

Engine diagnostics is the process of examining your automobile to identify potential issues. As the majority of modern cars come equipped with an inbuilt computer, the diagnostic process is mostly done electronically through tools that can pinpoint particular issues.

In this regard, it’s a good thing that most cars today are more electronic than they have ever been. In order to maintain your automobile in top operating condition, computerization really makes it possible for cars to undergo extensive inspections through self-running diagnostic checks.

These tests can detect mistakes or faults in an automobile’s integrated systems and componentry before they become seriously harmful. 

How Often Are Car Diagnostic Tests Needed

A few signs to look out for when considering whether you need to have an engine diagnostics test include:

  • The check engine light is on
  • You notice excessive exhaust smoke
  • There are unexpected stalls
  • Your car is consuming more fuel than usual
  • Suspicious sounds and smells
  • Any other engine-related issue

Most of the time, drivers wait to have a diagnostic done on their cars until they take them to an auto body shop or technician. Before giving in and taking their car to the local mechanic, a lot of other drivers will wait until there is a problem or the “check engine” light flashes.

Regular auto maintenance can maintain the health of your car. It is best to do a diagnostic engine check at least once in a year. When there is a problem with our car, we as drivers sometimes cannot see it or even feel it. It is not always easy to determine if your engine is performing at its best or not. However, when the engine light is on, there is no doubt that this should be resolved as soon as possible.

Technicians may utilize a variety of tools to speed up the repair process by rapidly and effectively identifying problems. On the other hand, you could want to educate yourself on how to run a basic diagnostic test. You can frequently check your automobile for problems and stop any major flaws from developing over time with the correct tools. If you want to go this route, it’s a good idea to do a car diagnostic test once a season, or quarterly.

When it detects an issue, it is configured to activate the check engine light. Engine diagnostic tools may rapidly and correctly identify issues with an automobile’s engine or other parts by using specialist software.

What Does an Engine Diagnostics Test Include? 

An extensive engine diagnostic will consist of getting data back. To accurately diagnose the vehicle, an onboard computer system looks for computer codes, freeze-frame data, software version numbers, crucial sensor data, and status information.

It would also include testing for verification. This establishes if the system complies with the standard correctly. At this point, the engine’s vacuum and back pressure, fuel and ignition systems, and emissions system are all being tested.

A failure in these systems can cause the warning light to appear, although it could be falsely highlighting a problem with a circuit or component that could lead to unnecessary replacements of certain parts.

It is also a manufacturer requirement to pinpoint test the circuit or component in order to make a well-informed diagnosis. This process includes wiring diagrams, electrical and mechanical tests, bi-directional control tests and visual inspections.

Another part is utilizing service bulletins. This helps find out whether the problem has been a recurring issue that is known for a particular vehicle type. There is still the need for testing, as certain systems cannot have a service bulletin performed on them.

After the engine diagnostics, there might be a need for repairs. This includes replacing parts, cleaning components, carrying out manufacturer’s technical updates, making updates to the vehicle’s software and wiring repair or replacement.

After all the necessary work has been completed, the vehicle needs to be re-tested. So, next time the warning light shows up, remember to get your car booked into your local car garage as soon as possible and let the experts sort the problem out for you!


As with any other car maintenance procedures, engine diagnostics must not be neglected, as it can result in more complicated and costly issues down the road. After all, the engine is one of the most essential components of a vehicle.

With the use of engine diagnostics, the mechanic can identify the malfunction in your car and fix it more quickly and efficiently. Looking for a trustworthy engine diagnostic near me place? You can rely on Smog Mart – the experienced technicians from Sacramento to get the job done.