How to Use an OBD2 Scanner (Step-By-Step Guide)

An OBD2 scanner can help you or your mechanic understand if your car’s in good shape.

The OBD2 scanner is a diagnostic tool that connects to your car via the Diagnostic Link Connector. This is done through a wired connection, WiFi or Bluetooth device, allowing you to scan every diagnostic trouble code generated by your car’s computer.

But the question is, how to use an OBD2 scanner?
In this article, we’ll show you step-by-step how to use an OBD2 scanner. We’ll also answer some related FAQs to give you a better understanding of this tool.

This Article Contains:

How to Use an OBD2 Scanner? (Step-By-Step)
3 FAQs on How to Use an OBD2 Scanner

How To Use An OBD2 Scanner? (Step-By-Step)

Running diagnostics on an OBD2 car scanner is simple and straightforward.
Here’s a simple step-by-step guide:

Step 1: Locate the Diagnostic Link Connector
Step 2: Connect Your OBD2 Code Reader or Scanner to the DLC
Step 3: Enter the Information Requested on the Scanner Screen
Step 4: Access the Scanner Menu for OBD Codes
Step 5: Identify and Understand the OBD Codes
Step 6: Move on to Trouble Code Diagnosis
Step 7: Reset the Check Engine Light

Step 1: Locate the Diagnostic Link Connector (OBD Port)

If your car was manufactured after 1996, it features a Diagnostic Link Connector (DLC) or OBD2 port. This is a 16-pin connector located on the left side of the driver’s dashboard underneath the steering column, usually covered with a door or flap.

In case you can’t find the OBD2 port, you can always check your owner’s manual.

Step 2: Connect Your OBD2 Code Reader or Scanner to the DLC

After locating the DLC, make sure your car is turned off.
Plug the end of the OBD2 scan tool into the Diagnostic Link Connector with an OBD2 connector cable. If you own a Bluetooth OBD2 scanner, directly insert the scanner into the OBD2 port and link to the necessary mobile app to read engine codes.

Next, check the scanner instructions on whether you should keep the car in ON or idle mode after connecting to the DLC. This step is important because following the wrong method can damage the scan tool app.

Following the correct instructions allows your diagnostic scanner to communicate with the car’s computer. Confirm the connection to your OBD II system by checking for a message on your OBD II scanner.

Step 3: Enter the Information Requested on the Scanner Screen

Your car has a Vehicle Identification Number (VIN). Depending on your scanner, you’ll have to enter the VIN before it can generate any OBD code.

The code scanner may also request other details like your engine and model type.

Where can you find the VIN?
If the scanner requests it, you can find the VIN on a sticker normally in the lower corner of the windshield on the driver’s side. Other places include under the hood next to the latch and at the front end of the vehicle frame.

Step 4: Access the Scanner Menu for OBD Codess

Now go to the code scanner menu screen, where you can pick between the different car systems.
Select a vehicle system so the scanner can show all active and pending engine codes.

What’s the difference?
Active codes trigger the check engine light while pending codes indicate the failure of an emission control system.

Remember, reoccurring pending codes can become active codes if the same issue keeps popping up.

Note: The car code reader or scanner display varies depending on your scanner type. Some will reveal only a problematic diagnostic trouble code, while others let you choose which OBD2 code you want to see.

Step 5: Identify and Understand the OBD Codes

With the diagnostic codes displayed, it’s time for you to interpret them.

Each OBD code begins with a letter followed by a set of four digits.
The letter in the diagnostic trouble code can be:

P (Powertrain): Indicates issues with the engine, transmission, ignition, emissions, and fuel system
B (Body): Indicate issues with airbags, power steering, and seatbelts
C (Chassis): Implies issues with axles, brake fluid, and anti-lock braking system
U (Undefined): Highlights issues that don’t fall under the P, B, and C categories

Now, let’s understand what the set of numbers implies in a fault code:

The first number after the letter will tell you if the diagnostic trouble code is generic (0) or manufacturer-specific (1)
The second digit refers to a specific vehicle part
The last two digits tell you the exact problem

Note down the OBD codes displayed by the scanner and turn off your car. Then, carefully unplug the OBD II scan tool.

If your scanner supports it, you can also transfer the diagnostic information to your laptop via a USB cable or Bluetooth. If you can’t read live data from your OBD scanner, contact your mechanic for help.

Step 6: Move On To Trouble Code Diagnosis

The OBD scanner or code reader tells you what’s wrong with your car, but it can’t tell you how to fix the problem.

So, figure out if the error code implies a minor issue or not.
And then, you can decide between a DIY approach or professional help. However, it’s best to take your vehicle to a certified mechanic’s shop to avoid expensive mistakes.

Step 7: Reset the Check Engine Light

Once your car’s issues are fixed, the check engine light should turn off after driving it for a little bit. But you can always use your OBD II scan tool to clear codes immediately.

How?
Go to the main menu of your OBD2 reader and find the check engine light option. Then, press the reset button. Give it a few seconds or minutes, and the engine light should turn off.

Note: You can use the scan tool to erase an error code and stop the check engine light from lighting up temporarily if the issue isn’t fixed. However, the check engine light will illuminate again since the problem still exists.

Now that you know how to use an OBD 2 scanner, let’s answer some FAQs.

3 FAQs On How To Use OBD2 Scanner

Here are some common OBD II scanner related questions and their answers.

1. What’s the Difference Between an OBD1 and OBD2 Scanner?

The OBD2 device or scan tool uses OBD2 technology and is more advanced than the OBD1 (OBD I) scanner.
Note: OBD stands for “on-board diagnostic”.

The main differences include:

An OBD1 scanner needs a cable to connect. An OBD2 device can be connected via Bluetooth or WiFi with diagnostic information displayed through an OBD2 app.

An OBD2 scan tool supports cars built in 1996 and after (with the OBD II system), whereas an OBD1 scan tool is compatible with cars only made in and before 1995. That’s why an OBD 2 scanner is more standardized than an OBD1 scanner.

2. What Are the Different OBD II Scanner Types?

There are multiple OBD2 diagnostic code reader types available. However, they’re mainly categorized into two kinds:

1. Code Reader

An OBD2 code reader is affordable and readily available. It lets you read every fault code and clear them. However, the OBD2 code reader isn’t the most advanced diagnostic tool for the OBD2 vehicle, so it can’t fully support manufacturer-specific OBD codes.

2. Scan Tool

A professional scan tool is an advanced car diagnostic tool that’s usually more expensive than a code reader and has advanced features compared to a diagnostic code reader. For example, a scan tool provides access to recorded data that you can playback live.

Unlike a code reader, the professional scan tool reads the vehicle manufacturer and enhanced diagnostics codes. Some car scanner tools may even have diagnostic equipment like multimeters or scopes.

3. What Things Should You Consider While Buying an OBD2 Scanner?

When buying a car diagnostic tool like an OBD2 scanner, here’s what you need to consider:

Look for an OBD II scanner with the latest technology for compatibility with your future vehicles. Moreover, an advanced OBD2 code reader or scanner tool will efficiently detect and describe your car issues.

Look for an OBD 2 scanner that’s user-friendly. A friendly and intuitive user interface will help you navigate and read the OBD codes easily.

If you’re looking for a handheld scanner, ensure the size is easy for you to hold.

Get Your Trouble Codes Resolved with AutoNation Mobile Service

The OBD 2 diagnostic scanner is for everyone, whether it’s a Bluetooth scanner, a built-in one, or a handheld scanner that needs a wired connection to the OBD port. Anyone can easily detect needed vehicle repairs inexpensively with it.

The only tricky part is fixing the issue detected by your car code reader. For that, you have AutoNation Mobile Service.

We’re a mobile auto repair and maintenance solution. Our auto experts will diagnose OBD codes for you and help you resolve them right from your driveway. Available 7 days a week, you can book our services through an easy online process.