Understanding OBD-II Scanners

OBD-II-Scanners

An OBD-II scanner allows you to read and clear Diagnostic Trouble Codes (also known as fault codes, DTCs) on vehicles 1996 and newer.

OBD-II-Scanners

Your dealer and mechanic use OBD-II scanners to diagnose most of the problems with today’s vehicles.  While the scanners used at the dealership are the most advanced and expensive, aftermarket scanners are readily available for DIYers who want to troubleshoot their vehicles.

Which OBD-II scanner should I buy?

Entry-level OBD-II (OBD-2) scanners start at about $20 but can only diagnose the check engine light. On the end are the professional scanners that can go over $1000 and will be able to read, clear, and program any module in any car.

We divide scanners into three categories to help you choose the best OBD-2 scanner.

  1. Level 1 – Basic Code Readers, Least Expensive, Can only read and clear codes from the Engine Control Unit (ECU).
  2. Level 2 – Multi-system OBD-2 Scanner, Can read and clear codes from Engine, Transmission, ABS, and Airbag. Depending on the scanner, it may be able to read and clear codes from other modules such as climate control, suspension, charging system, etc.
  3. Level 3 – Professional OBD-2 Scanners, Professional Level, These scanners offer similar functionality to what the dealer uses. They can read, clear, program, view live data, and activate all systems in your car.

We hope that after reading this article, you will have a better understanding of OBD-2 scanners. Regarding OBD-2 scanners, there is no one size fits all solution. A key component is how much you are trying to spend on a scanner and whether you want it to work on only one make or many vehicle models.

When buying an OBD-2 scanner, ask yourself these questions:

  1. What are you trying to diagnose?
    • Check Engine Light,
    • ABS Problems
    • Airbag / SRS Light
    • Transmission Problems
    • Program Modules
  2. What is your budget? 
  3. Do you need a scanner to work on one make (for example, BMW) or multiple makes? 

Level 1 OBD-2 Scanners

basic obd2 scanner

These basic OBD-2 scanners (code readers or generic OBD-2 scanners) retrieve data from the Engine Control Unit (ECU).

You can retrieve Diagnostic Trouble Codes (DTC) (also referred to as fault codes) that trigger the Check Engine Light and Service Engine Soon. Level 1 scanners don’t access other modules besides Engine Control Unit (ECU) or provide any coding capabilities.

Simply plug into the OBD-2 port and read the code. They show you a fault code. A few scanners even tell you what the code means. Regardless of what description you get from the scanner, write down the code, and do online research to understand what common problems are with your make.

Capabilities

Here is a list of what you can do with these scanners:

  1. Read Fault Codes from Engine Control Unit
  2. Determine why Check Engine Light is on.
  3. Erase Check Engine Codes
  4. View Freeze Frame Data
  5. Display live sensor data from ECU

Limitations

  • It can not access other modules.
  • Can not read codes from ABS, SRS, transmission, etc.
  • Can not troubleshoot TPMS
  • No programming or coding

Most Level 1 scanners sell for under $100. Typically can only diagnose the Check Engine Light or Service Engine light.

Many of these scanners can display live sensor data that the Engine Control Unit controls. Level 1 OBD-2 scanners cost as little as $15. Every car owner must, at a minimum, have one of these cheap OBD-2 scanners in the glove box.

Level 1 OBD-II Scanners

ANCEL AD310 Classic Enhanced Universal OBD II Scanner Car Engine Fault Code Reader CAN Diagnostic Scan Tool - Black ANCEL AD310 Classic Enhanced Universal OBD II Scanner Car Engine Fault Code Reader CAN Diagnostic Scan Tool – Black
TT TOPDON TD300 OBD2 Scanner Code Reader with Engine Light Turn-Off TT TOPDON TD300 OBD-2 Scanner Code Reader with Engine Light Turn-Off
BAFX Products Bluetooth Diagnostic OBDII Reader BAFX OBD2 Products Bluetooth Diagnostic OBDII Reader
BlueDriver Bluetooth Professional OBDII Scan Tool for iPhone, iPad & Android BlueDriver Bluetooth Professional OBDII Scan Tool for iPhone, iPad & Android
Veepeak Mini WiFi OBD2 Scanner Compatible with iOS and Android, Car OBD II Veepeak Mini WiFi OBD2 Scanner Compatible with iOS and Android, Car OBD II

Level 2 Multi-System OBD-2 Scanner

level 2 obd2 scanner

Level 2 scanners (also called multi-system OBD2 scanners) are slightly more expensive, but their main advantage is that they allow you to read and clear fault codes from many modules.

If you work on cars frequently or are trying to troubleshoot problems other than the check engine light, you need multiple system OBD-2 scanners.

These scanners can reset the check engine light and read and clear codes from various modules, including Anti-Lock Brakes, Airbag systems, Transmission, Tire Pressure Monitoring systems, etc.

Several multi-system scanners only read clear codes from the engine, transmission, abs, and airbag modules, while a full system OBD-2 scanner will be able to read, clear, and reset fault codes from almost all modules on the vehicle. A full system OBD-2 scanner is the way to go if you work on cars frequently. One trip to the dealer could save you enough money to buy one of these scanners.

Even if you haven’t used a full system OBD-2 scanner before, don’t worry. They are very easy to use and function like basic OBD-2 code readers. The main difference is that they can access another system in your car, not just the ECU.

One popular scanner in this category is the Launch Creader Multi-System Scanner.

Capabilities

  • Read/Erase Check Engine Codes
  • Read/Erase ABS Fault Codes
  • Read/Erase Airbag / SRS Codes
  • Troubleshoot transmission problems
  • View Sensor Live Data

Limitations

  • No Coding
  • No Programming
  • One-directional communication

Level 3 Professional Diagnostic Scanners

professional level scanners

Professional diagnostic scanners provide similar functionality to the scanners used at your car dealerships. These are meant for mechanics that operate auto repair shops.

If you are a DIYer and can afford a professional diagnostic scanner, you may never need to go to the dealer or mechanic. Level 3 diagnostic scanners are expensive, with most of the scanners ranging between $1000 and $3000. Level 3 scanners offer bi-directional support and can diagnose all system and control units.

A complete system expert scanner is not limited to one make but works on most car brands, including Honda, Toyota, BMW, VW, Mercedes, Porsche, Ford, Chevrolet, etc. Bi-directional supports allow you to activate, program, and test sensors and systems in your car. These are professional scanners and are more expensive. These professional OBD-2 scanners are often used by auto mechanics and offer full system diagnostics.

We have included a few that are easy to use by mechanics and car owners who can afford one. Level 3 OBD-2 scanners offer a bi-directional function, which means you can activate and test various sensors on the car. Many car manufacturers require that the dealer can only code certain modules. Professional scanners will not be able to code the replacement of certain modules if the dealer can only complete the coding.

Popular Level 3 Scanners

  • Autel MaxiDAS All System Scanner
  • Snap-On Solus
  • Launch All System Scanner All Makes

We hope you find the Understanding OBD-II Scanners guide helpful. Check these troubleshooting and repair guides for more help on your vehicle.

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