What Can a Car Diagnostic Test Tell You?

Car diagnostic tests are part and parcel of owning a modern automobile — whether it’s on the bleeding edge of today’s technology or over a decade old. While many people are unaware of the importance of a car diagnostic test and do not visit a workshop until they see the ‘Check Engine’ light (CEL) illuminating, or a similar message in their Multi Information Display (MID), the savvy owner and driver knows the importance of regular car diagnostic tests in ensuring a reliable and stress-free journey. Let us talk about what a car diagnostic test can tell you and introduce a way in which you can save time and money by doing it yourself.

So, what does a car diagnostic scan tell us? Well, it basically tells us the health of the car’s many computerized control units. A modern car can have upwards of fifty such control units, and each one is connected via kilometers of wiring, hundreds of sensors, and millions of lines of computer code. A car diagnostic scan can tell you what’s wrong, what can possibly go wrong in the near future, and the current status of your car’s systems. With consumer-grade solutions like Carly, you can even do a car diagnostic scan yourself.

How does it all come together? OBD makes it happen. Let’s have a very quick explanation of that first.

What Is OBD?

What Is OBD?

OBD, or On-Board Diagnostics, is an interface and protocol for checking the multiple computerized control units in a car for errors, as well as communicating with them. Now on the second iteration, called OBD2, it’s a unified standard that any car since 2004 will have, regardless of make and model. It’s accessed via a standardized OBD2 port located within the cabin, usually within a few feet of the steering wheel. Common places include beneath the dashboard or steering column, in the glove box or storage cubbies, or in the footwell behind a trim panel. Your car’s owner’s manual or an internet search can help you find it.

What Can a Car Diagnostic Tell Me?

Starting from the basics, a car diagnostic can tell you if there’s an issue with your car’s critical systems, such as the engine control system, emissions control system, braking system, steering system, and safety systems such as airbag controllers. These are critical for the functionality of the car, as well as safety of life, so ensuring that any errors are quickly detected and corrected is paramount.

The CEL or MID may not always indicate an error. For example, if an engine control sensor throws up an intermittent bad signal, the car’s control unit is smart enough to know that it’s not an urgent issue until it becomes one. Ditto if your brakes pads are moderately but not significantly worn down. However, regular car diagnostics scans can allow you to capture these potential issues before the CEL, or MID alerts you to it and act accordingly.

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What Else Can a Car Diagnostic Scan Tell Me?

In addition to communicating the status of the critical systems, a car diagnostic scan can allow you to identify issues in other systems, such as the infotainment system and climate control system. If you are facing an intermittent problem in these systems, this is the best way to determine the root cause.

Additionally, a diagnostic scan can alert you to upcoming service and maintenance tasks depending on the vehicle’s mileage and driving conditions, and allow you to monitor certain parameters such as engine RPM, fuel consumption, coolant and oil temperatures, current speed, GPS information if so equipped, and more.

Are Car Diagnostic Scans Costly?

Are Car Diagnostic Scans Costly?

Your typical workshop will charge between $30 and $80 for a car diagnostic scan. There can be instances when all or part of the scanning charge will be waived off, such as if your car is under warranty and scanning is included in it, if the workshop is running a promotion, or if you’ve agreed for the workshop to undertake any required repairs.

Bearing in mind that you should perform a car diagnostic scan at least four times a year, or once every three months — more often, if you rack up more than 10,000 miles in a month — the costs can quickly add up. You will also waste your precious time driving to and from the workshop, as well as waiting for your car to be scanned.

How Can I Do a Car Diagnostic from Home?

This is where consumer-grade OBD scanning devices come into the picture. There are many forms: Some are dedicated handheld devices, while others consist of a cable and software to run on a laptop. The third type is the most versatile, and that’s a wireless adapter that plugs into your vehicle’s OBD2 port and communicates wirelessly with your smartphone and an accompanying app. Some adapters can work with various apps, while others are designed to work hand-in-glove with a particular app. Carly is one such solution, consisting of a hardware adapter and software app that are designed to run 100% in synergy.

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Meet Carly

Meet Carly

Carly consists of the Carly Universal OBD Scanner, a pocket-sized scanner that plugs into your vehicle’s OBD2 port and wirelessly communicates with your smartphone. You must install the Carly app on your smartphone, and it can be downloaded from the Apple or Android app stores. The full version of the app is paid, but there’s a free Carly lite app that allows you to try out some functions before committing.

Carly will cost you less than $100 for the adapter and app, which is an absolute steal! Just using Carly three or four times means you’ve already recouped the cost of car diagnostic scans, and subsequent scans are in effect free of charge. You can do them from the comfort of your home, or anywhere else while parked. Carly regularly updates their app, so there’s no danger of it becoming obsolete. Carly presents scan results in a clear and easy-to-read interface, with plain English explanations of the issues rather than displaying the raw error code, which can be confusing for novices, and requires additional internet research to decipher.

There’s More than Just Scanning with Carly

Carly doesn’t just offer diagnostic scanning and stops there. The app also allows you to code various aspects of your car, such as the duration of the headlamps after you’ve locked the car, the beeping behavior of the horn when locking and unlocking, how many times the indicators flash, deactivate the engine start-stop system, and much more. Of course, what can be coded is dependent on the make and model of your car.

You’ve also got the Carly Used Car Check as a powerful ally when checking out a used car. Mileage tampering is a massive problem when purchasing a used car, as unscrupulous sellers simply roll back the mileage on the odometer to command a higher price. Carly meticulously checks all relevant control units and compares parameters to detect this in a way that most other tools fail.

If you’re a DIY maintenance person, Carly is an excellent tool for this, as it allows you to set and reset the maintenance minders of your car, such as resetting the oil change interval after you’ve done an oil change in the comfort of your garage.