Our editors pick the products & services we write about. When you buy through our links, we may get a commission. Learn more.

OBD1 vs OBD2: Definite Guide on How to Determine Your Vehicle

When your check engine light is on or you’re experiencing car problems, an appropriate OBD scan tool will let you talk to your car and help determine what the problem is.

But, you may ask yourselves:

– What type of OBD is my car? And,

– What kind of OBD scanner should I use, OBD1 or OBD2 Scanners?

In this article, we’ll discuss in details the difference between OBD1 and OBD2 vehicles and the best OBD Scanner for them.

obd1 vs obd2

What’s OBD, Anyway?

OBD-II type A female connector shape
OBDII connector shape.
Credit: commons.wikimedia.org

OBD stands for On-Board Diagnostics. Your car’s onboard diagnostic system is a computer that’s in charge of monitoring your engine through a series of sensors.

These sensors detect any abnormalities in your engine, including:

  • irregularities in the fuel/air mixture
  • any problems with your catalytic converter
  • and spark plug issues, etc.

There’s a special plug that allows you to use a scan tool to communicate with this system directly so you can figure out what’s going on with your car.

A video about OBD introduction

OBD1 vs OBD2 Comparison chart

NatureCalifornia StandardFederal Standard
Years Used1991-19951996-present
FunctionRetrieve diagnostic information and inform drivers of engine problemsRetrieve diagnostic information and inform drivers of engine problems
InterfaceManufacturer specificUniversal interface
ApplicationWas not able to gain much popularityWas implemented from the beginning because of the options available
BenefitTotal energy and fuel consumed by the vehicle and then output which comes outTakes into account different calculations and codes to solve the problems that are faced

Improvements From OBD1 to OBD2

OBD Auto Scanner connecting to the ECU
OBD auto Scanner.
Credit: commons.wikimedia.org


Despite OBD1 being a California state standard, it’s found on many cars that were made during the early 1990s.

OBD2 has been required nationwide since 1996, so it’s present in virtually every US car manufactured since then.

In other words, OBD2 is the tool you need in almost every situation.

Years used

OBD1 was phased out with the introduction of the newer OBD2 standard. This standard is still in use today, so you can use the same scan tool on a car made in 1996 and one made in 2016.

Again, OBD2 scan tools are the type of tool you’ll want to use in every modern car.


While OBD1 wasn’t exactly the same as OBD2, it was fundamentally pretty similar. The point of the system was to allow your car to monitor itself and relay useful information to drivers and mechanics.

OBD2 is simply an updated, standardized version of the same system.


The biggest improvement from OBD1 to OBD2 is that all OBD2 cars have the same sort of ports that send the same sort of data the same way.

In other words, you can buy a single OBD2 scanner and get useful information from any car made by any manufacturer.

Is My Car OBD1 or OBD2?

OBD1: California Standard For Old Cars

In 1991, California introduced a standard called OBD 1 in order to curb vehicle emissions.

All cars had to be equipped with a system that could detect engine issues and report trouble codes. Unlike the later OBD2 standard, however, OBD-1 wasn’t standardized across manufacturers.

This means that an OBD-1 scan tool will often work for only one make of car. In addition, the codes themselves aren’t standardized, so a Ford with the same engine issue as a Toyota might give a totally different trouble code.

As you might imagine, this standard wasn’t very useful.

OBD2: Universal Nationwide Standard

When Did OBD2 Start? OBD2 became a nationwide standard in 1996, and it’s been used ever since then.

Unlike OBD1, OBD2 equipped cars all support the same type of scanner. The trouble codes themselves have also been standardized, although manufacturers sometimes allow the system to send additional specific information.

As car computers have got more and more sophisticated, car manufacturers have added more and more capabilities to the OBD2 systems in their cars.

As a result, you can use an OBD2 scanner to view real-time diagnostic data, interface with your car’s computer, and more.

A video about OBDII Introduction

OBD1 vs OBD2 Scanners

The difference between OBD1 and OBD2 Scanners

OBD1 scanners only work on old cars. If a car was produced after 1996, it probably doesn’t have an OBD1 port, so you can’t use an OBD1 scanner with it.

Even if your car was produced before 1996, you’ll still have to find an OBD1 scan tool that matches that car’s specific manufacturer and find a way to translate that manufacturer’s specific error codes into a format you understand.

Car makers understood that mechanics wouldn’t want to buy five or six different scan tools in order to work with different types of cars. As a result, most OBD1 equipped cars can transmit error codes in a different way.

With a bit of work, you can configure these cars to flash out these error codes in code via the check engine light.

By contrast,

OBD2 scanners are necessary to retrieve error codes and diagnostic information from more modern cars.

If a car was made after 1996, you’ll need an OBD2 scan tool in order to interface with the car’s diagnostic system. Luckily, you don’t have to worry about make or model.

OBD2 scan tools are totally universal as far as newer cars are concerned.

Should I Use OBD1 or OBD2 Scanner?

If the car you’re trying to service was produced for use in the United States after 1996, you definitely want an OBD2 scan tool.

The only time you’d want an OBD1 scanner is when you’re trying to service an older car (made before 1996) but you can’t figure out how to put the car in “service mode”. So, it flashes out error codes via dashboard lights.

Even then, the hassle of finding a manufacturer specific scan tool and figuring out how to read the proprietary error codes might not be worth it.

For cars made after 1996, however, OBD2 scan tools are invaluable. So, if you’re a professional auto mechanic, you’ll probably need to have both OBD1 and OBD2 scanners in your garage cabinet.

They allow you to smoothly connect with your car’s internal systems and quickly figure out the cause of your engine problems. This can allow you to perform cheap DIY fixes yourself or simply make informed decisions about work you’ll let your mechanic do.

Modern technology has made these scan tools affordable enough for any car owner. So, you can often save money by buying an OBD2 scanner and seeing what your car has to say before you take it to the shop.

To Summarize

OBD1 scan tools work with cars made by a specific manufacturer before 1996.

OBD2 scan tools are universal and work with all cars made for the US market by ANY manufacturer as long as these cars were made in 1996 or newer.

You do need to actually buy an OBD2 scan tool to access the car system.

Read more: SRS Light / Airbag Light on – What should I do?

Tim MillerFounderOBD Advisor

I’m Tim Miller from Denver, Colorado. I’m the founder of obdadvisor.com, an automotive blog about "Auto Diagnostic Tools and Repair Guides". My fan page is facebook.com/autozikcom. I've been working as an automotive mechanic and blogger for over 10 years writing articles to share my experiences and expertise.

Web: https://www.obdadvisor.comEmail: [email protected]
Follow me:

29 thoughts on “OBD1 vs OBD2: Definite Guide on How to Determine Your Vehicle”

  1. The “check engine soon”light stays on most of the time.
    1995 Pontiac Grand Prix. Car runs great! Can’t find any one who has OBD1. Any advice? Ken

    1. Hey Frank,

      Because you didn’t tell me types of tests and functions the scanner should have, I would recommend the best of today’s products for your choices.
      1. BAFX Bluetooth OBD2 Code reader: This is a cheap OBD2 code reader, with various features: https://www.obdadvisor.com/bafx-scanner-android/
      2. Foxwell NT301 Full OBD2 Cable Code Reader: https://www.obdadvisor.com/foxwell-nt301/

      3. Launch CRP123 Engine, ABS, SRS Cable scanner: https://www.obdadvisor.com/launch-crp123-vs-crp129/

      If you just want to do simple OBD2 test, take either BAFX or NT301. The Launch CRP123 is for you if you want to do some more complicated service functions like ABS, SRS Diagnosis.

      Any questions are welcome.


  2. I have an obd1 car but I can’t find an obd1 reader can I use an obd1 to obd2 adapter and use an obd2 reader?

    1. Hey Mike, yes, you can use an obd1 to obd2 connector to use an obd2 reader on your car. But make sure that the code reader is compatible with your car make and model.

      What is your car model, VIN…?

  3. limo services orlando

    OBD is onboard diagnostic, a process to scan vehicle with an onboard computer. In its early phase, the development of OBD system was mainly to turn on the malfunction light in cars. Later more standardized and vehicle’s information was developed in OBD1 and OBD2 respectively. I have OBD1 car can I use obd2 adapter and reader?

  4. So i have a 1994 hyundai Elantra with an obd1 port what obd2 scanners will work on it note that i have the right obd1 to obd 2 cable in hand and thanks in advance

  5. Hi – looking for a recommendation for a converter cord for a Lexus 94 OBD1 to OBD2. Work requires that I plug in a Tracker from a cell phone company. The trackers are new and on the OBD2 system.

  6. Have a 1992 3000gt sl. Alot of issues trying to get it to idle and run correctly. New fuel pump, injector tube and injectors, new IAC, new coils spark plugs and plug wires. Will an obd1 scanner or reader allow me to change or modify individual sensors, i e throttle position sensor, maf sensor, BISS and SAS screws

  7. I have a 2005 Subaru Empreza in Australia, but could not use my obd2launch. There seems an error which looks it’s not connected to the ecu. There’s an occasional check engine to my Empreza.

  8. Tim – What cheap-to-mid price scanner would you recommend for use on Saabs? My cars are 1989 and 1993 900’s, 1999 9-3’s, 1994 9000, and a 2002 9-5. My problems are “ck engine”, and “SRS”, and “transmission failure.” Prefer a stand-alone unit, not one requiring a phone or laptop. Thanks for all the work you do on the ‘net.

Leave a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top