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How to Use an OBD2 Scanner: A Guide for the Everyday Driver

Personally, I carry an OBD2 scanner in every vehicle we own. And once, it even saved us from getting stranded in the middle of nowhere! We think every driver should have and know how to use an OBD scanner for their vehicle. It’s one of the easiest and first steps to diagnosing problems in almost any passenger vehicle today. Even if you cannot fix the problems it shows, it will point you in the right direction of how to get it fixed.

Today, we’ll walk you through how to use an OBD2 scanner and share the story of how ours saved us from catastrophe.

What Is an OBD2 Scanner?

An OBD2 scanner is a universal diagnostic tool for automobiles. Only professionals used them in the past, but technological advances have made them readily available and affordable for most drivers. 

OBD is an acronym that’s short for onboard diagnostics. These devices connect to the vehicle and read diagnostic trouble codes (DTCs). By identifying the DTCs, the owner can address issues and malfunctions within the vehicle. In addition to DTC’s, some scanners can make slight programming changes to the vehicles.

They come in various shapes and sizes. Entry-level models are typically handheld versions and have limited features. However, more advanced models use Wi-Fi and Bluetooth to connect to computers, smartphones, and tablets. The most capable versions transmit real-time data regarding fuel efficiency, emissions, and engine performance.

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cheap obd scanner plugged into car
Easily diagnose your vehicle’s issues with an OBD2 scanner. This is one of our inexpensive scanners

Why You Need an OBD2 Scanner

If you are want to see an OBD scanner save our bacon, you can watch episode 9 of our Go North series. We had an encounter with porcupines that tried to destroy our truck when it was extremely remote in northern Canada. With the scanner and an electrical repair, I was able to reset trouble codes that could have disabled the truck completely!

Now, you might not be offroad in the middle of nowhere, but an OBD2 scanner can tell you where to start with car troubles. They make identifying issues with your car straightforward. You can quickly identify the cause of the “check engine” or other error lights illuminating your dash. If you know what the problem is you might easily be able to replace a sensor, or at least talk to your mechanic about what’s wrong. Knowing what your scanner says can also help prevent you from being taken advantage by a mechanic.

These devices can also help you monitor your vehicle’s performance. The most advanced models provide real-time data. Accessing these insights can help you identify issues and optimize your driving habits.

Finally, an OBD2 scanner can help ensure your vehicle complies with emissions regulations. Some drivers live in areas with strict rules regarding emissions. By monitoring the output, you can save yourself from failing an emissions test, receiving a fine, or harming the environment.

Pro Tip: Make sure you have these 36 Most Important Tools You Need In Your RV Tool Kit in case of emergency.

Trouble with Wildlife, Canol Road, Top of the World Highway & Crossing into Alaska! | Go North Ep 9
An OBD scanner comes in very handy in this adventure of ours!

Does a Car Have to Be Running to Use an OBD2 Scanner?

You do not need to run your vehicle to use an OBD2 scanner, but usually, the key needs to be turned to the accessories position. Sometimes, it’s easier to use these devices without the car running. This is particularly true when working in a tight space or diagnosing the ignition or starting system.

While you can use an OBD2 scanner while the vehicle runs, you should turn it off before connecting it to your car. This can help you avoid potential safety hazards or damage to the unit or vehicle. It’s better to be safe than sorry. 

Our wireless obd scanner
This is our wireless OBD link scanner plugged in, the vehicles needs to be in ACC mode for it to connect to the phone.

How to Use An OBD2 Scanner: A Guide for the Everyday Driver

First you need to purchase an OBD scanner. A quick search will yield tons of inexpensive options for $10-20. To be honest, if you are just pulling codes, these work great, and there is no need to spend more. If however, you want to pull live data and make some changes to your vehicle (only do this if you are confident you know what you are doing) I highly recommend the OBD Link LX or MX series wireless units. These are my go-to for most of my needs. For full vehicle reprogramming, advanced scanners will be needed, however, and that is outside the scope of this article.

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Once you have your OBD2 scanner, you’ll want to test it out. You don’t have to wait for something to go wrong to use it; you can get plenty of information without breaking something. Let’s walk through each step so you can get comfortable using your device.

Locate the OBD2 Port

The first step is to locate the OBD2 port on your vehicle. This is the Data Link Connector (DLC), and you’ll most likely find it under the dashboard on the driver’s side. It will be near the steering column. You may benefit from kneeling and using a flashlight to get a better look.

Some vehicles do put it in weird spots or hide it. I once had a Volvo that required removing the ashtray on the dash to find the plug.

If you’re unable to find it, check your owner’s manual. It will likely have a detailed graph or description of where to find it. You can also call a local dealership, service center, or a mechanically gifted friend for assistance.

Plug in the OBD2 Scanner

Now that you’ve found the port, it’s time to plug in the OBD2 scanner. However, you should ensure you’ve turned off the vehicle. You do not want to plug in the device while it is running. Some vehicles and device combos can cause weird things to happen.

With the engine off, line the connection on the scanner with the holes in the port. If properly aligned, the two connectors should have no issues sliding together. Use gentle but firm pressure. However, avoid using excessive force, as you can cause permanent damage to the pins in the port.

OBD2 scanner plug in
You can find the port for your OBD2 scanner under the dashboard on the driver’s side of your vehicle.

Turn the Key ACC Or Start the Vehicle

With the OBD2 scanner connected, you can turn the key to the accessory position. If you’re unfamiliar with this, it’s the position before starting the engine. It’s the same setting you’d use to listen to the radio without running the engine.

If it’s safe, you can also start the engine. Some diagnostic procedures will require you to do this. With the motor running, you can access codes and real-time data for your vehicle. However, if you’re working indoors or in a confined space, be aware of exhaust and the potential for carbon monoxide poisoning.

Navigate the Scanner

Once you’ve powered up your scanner, you must navigate the settings for your unit. Each scanner is very different, and you’ll want to ensure you know how to use your model. If your unit is wireless there will be a pairing procedure to connect to your phone or tablet. Follow the instructions for your scanner to do so.

These devices can range in complexity and take some time to learn. Don’t be too proud to read the instructions to ensure you know what you’re doing. You may discover new features or settings.

Read and Interpret Diagnostic Trouble Codes (DTCs)

After the scanner has done its job, it will retrieve any codes in the computer on your vehicle. These codes are the information you’ll likely need, especially if you’re experiencing troubles or issues with your car. 

Your OBD2 scanner will usually come with a manual to help you to interpret the codes. High-quality scanners will display more than the code but also its meaning. This can help you address the issue and get your vehicle back on the road.

There are two types of codes: standard DTCs and manufacturer-specific. Standard codes can usually be read by the scanner, but manufacturer specific may not. A simple online search of the code displayed and your vehicle type will typically show what the code is.

Man using portable OBD2 scanner
Your OBD2 scanner will provide a series of error codes to help determine what the problem with your vehicle is.

Clear Codes (If Fixed)

After resolving and fixing any issues, you can clear the error codes. However, removing the codes without fixing the issue will cause the error message to reappear in the future. It also doesn’t do anything to get to the root of the problem. This could damage your vehicle and cause the situation to go from bad to worse.

Seek Professional Help When Necessary

While there are some error codes that almost anyone can address, there are also error codes that require a professional. If your scanner displays a code that involves your transmission, engine, or computer system, you’ll want to seek assistance from a professional. 

These repairs typically require specific tools and expertise. If you accidentally bite off more than you can chew, you could do costly damage to your vehicle. We suggest you know your limits unless you want a large, expensive paperweight.

Pro Tip: Take care to avoid these 5 Most Common Causes of RV Accidents.

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Is It Worth Buying an OBD2 scanner?

In our opinion, a big Yes! We think everyone should have a scanner. However, knowing how to use an OBD2 scanner may not be necessary for the average driver. Thankfully, all auto parts stores and mechanics have these devices. Some will even connect them to your vehicle, pulling the error codes for free. However, getting your device can be worth it if you want to save yourself a trip or pull codes on your own.

Do you plan on buying an OBD2 scanner? Tell us your thoughts in the comments!

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About Tom Morton

Tom, a Pacific Northwest native, is our technical genius. Born in Washington and raised in Alaska before settling in Michigan. He's the man who keeps our operation running, both figuratively and literally.

With a background in Electrical Engineering, Tom specializes in RV solar systems and lithium batteries. He made history as the first documented individual to use a Tesla battery module as an RV battery. Tom has personally assisted countless RVers with system installations and has educated thousands more through his videos and articles.

Cinematography is another of Tom's passions, showcased in his work on the Go North series. You can see his camera skills on display in The RVers TV show on Discovery Channel and PBS where he also stars as a co-host.

Tom's mechanical expertise extends beyond RVs to boats, planes, and all things mechanical. He's renowned for taking on maintenance and repair projects single-handedly and is often spotted underneath RVs, making him the technical backbone of our endeavors.

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Monday 16th of October 2023

I have used the scanner in the past. I have always just gone to the auto parts store used the scanner and purchased my parts to fix the problem or know I need a shop. Now that I’m traveling more and need to be self sufficient owning one is a fantastic idea. Discovering too that everyone in an auto parts store aren’t as knowledgeable as you think or would like. I will be getting my own. Thanks for the article.