What Happens During a Full Vehicle Diagnostic Scan?

At a Glance

A full vehicle diagnostic scan connects to your car’s onboard computer to retrieve fault codes and analyse live system data. It checks key electronic systems, identifies underlying issues, and guides accurate repairs. The process is typically quick and can detect minor faults early, helping prevent more serious and costly mechanical problems. For a thorough diagnostic scan, book an appointment with In Town Automotive.

What Does a Vehicle Diagnostic Check Do?

Modern vehicles rely on complex computer systems to monitor performance, safety, and emissions. When something goes wrong, whether it’s a dashboard warning light or unusual behaviour, a full vehicle diagnostic scan can help quickly and accurately pinpoint the issue.

In this blog, we’ll explain what a diagnostic check on a car is and what exactly happens during this scan. We’ll also discuss how mechanics connect specialised equipment to your car’s onboard computer and analyse live data from key systems, including the engine, transmission, brakes, airbags, and emissions controls. 

What can a car diagnostic test tell you? Here’s everything you need to know about what it can and cannot do, as well as what happens after a fault is identified.

What a Full Vehicle Diagnostic Scan Actually Checks

A full diagnostic scan checks the main electronic systems that control how your car runs. Modern vehicles have an onboard computer that monitors components such as the engine, transmission, braking system, airbags, steering, and emissions system.

During the scan, specialised vehicle diagnostic equipment reads fault codes stored in the system and reviews live data from sensors throughout the vehicle. This helps identify issues such as misfires, sensor failures, electrical faults, and fuel-efficiency problems.

The scan can also detect hidden issues before they become serious. Overall, what is a diagnostic check on a car? Put plainly, it provides a clear picture of your vehicle’s electronic health.

How the Diagnostic Scan Connects to Your Car’s Systems

A diagnostic scanner connects to your car through an OBD (On-Board Diagnostics) port, usually located under the dashboard. A mechanic plugs a handheld scanner or computer into this port.

Once it’s connected, the device communicates directly with the vehicle’s onboard computer system. It reads stored fault codes, checks system status, and pulls live data from sensors across the car. This communication happens electronically and doesn’t require dismantling any parts.

The scanner translates technical information into readable data, allowing the mechanic to quickly understand what’s happening inside your vehicle’s systems. If your car needs a diagnostic scan, book an appointment with us.

Common Fault Codes and What They Mean

When a diagnostic is performed, it often reveals fault codes, which are short combinations of letters and numbers that point to specific issues. For example, a code might indicate an engine misfire, a faulty oxygen sensor, low fuel pressure, or a problem with the emissions system.

Each code corresponds to a specific area of the vehicle, helping the mechanic quickly narrow down the cause. However, a fault code doesn’t always mean that a part needs replacing. It just highlights where the issue is occurring, allowing for further checks to confirm the exact problem before repairs begin.

How Long Does Diagnostics Take on a Car

A full vehicle diagnostic scan is usually quick and straightforward. In most cases, the scanning process itself takes between 15 and 30 minutes. Once the mechanic connects the diagnostic tool, they’ll retrieve fault codes and review the system data.

However, the total time can vary depending on your vehicle and the number of issues detected. If multiple fault codes appear, further investigation may be needed to confirm the exact cause. This additional testing can take longer.

While the scan is fast, it’s important to understand and diagnose the problem properly. This ensures that repairs are carried out efficiently and accurately.

What Happens After the Scan Results Are Reviewed

Once the scan results are reviewed, the mechanic will explain what the fault codes mean and how they affect your vehicle. If the issue is clear, they may recommend a specific repair or parts replacement.

In some cases, additional testing may be required to confirm the cause of the issue before any work can begin. You’ll receive a breakdown of the recommended repairs and estimated costs.

At this stage, no work should be carried out without your approval. The goal is to ensure that you understand the problem and the next steps so repairs can be completed correctly and safely.

When a Diagnostic Scan Can Help Prevent Bigger Repairs

A diagnostic check can help prevent bigger repairs by identifying small problems early. Many vehicle issues start as minor sensor faults or performance irregularities that may not seem serious at first. However, if left unchecked, these issues can lead to engine damage, reduced fuel efficiency, or costly component failures.

By running a scan when a warning light appears, or during routine servicing, mechanics can detect faults before they worsen. This allows them to fix the problem early, which is often more affordable. In simple terms, a diagnostic scan acts as an early warning system for your vehicle’s health.

For an Effective Vehicle Diagnostic Scan, Contact In Town Automotive

Have you been asking questions like “What is a diagnostic check on a car?” or “What does a car diagnostic scanner do?” Now you know what it is and how it can help protect your vehicle’s systems.

At In Town Automotive, we use top-of-the-line vehicle diagnostic tools to conduct full-service scans and offer a FREE 16-point vehicle health check. Our mechanics are well-equipped to address a range of car issues to support your vehicle’s health.

To keep your car running safely and efficiently, we recommend sending it in for an all-inclusive health check. We have years of experience in fixing air conditioning, cambelts, exhausts, wheel alignment, and more.

With over 1000+ positive reviews on Google, we have a proven track record for delivering reliable car services. Explore our services page or contact us to book an appointment today.