What’s the Difference between OBD and OBD2 Systems?

When you’re looking for a new vehicle, the terms OBD and OBD2 can be pretty confusing, especially if you don’t have much experience working on a car or truck. OBD stands for onboard diagnostics. If you have a high-tech OBD system in your vehicle and it has a problem, then the OBD system will self-diagnose and can tell the technician what’s going on with the engine.

Learning the Basics of Old and New OBD Systems

With the recent advancements in technology came new improvements of OBD systems. These improvements allowed for faster diagnostics and an easier to use, more streamlined system.

So, what’re the main differences between OBD and OBD2? With OBD the goal was to develop a system for diagnostics that focuses on a vehicle’s emission control system.

But many pros feel that the OBD2 system is a big improvement over standard OBD. OBD2 offers better messaging formats and signaling protocols. When this system is used in emission control system tests it offers better results when it comes to a vehicle’s parameters.

OBDs were introduced way before OBD2 models, which only started in the early 90s. Basically, the OBD2 system is much better in the sense that if offers standardized trouble codes for vehicle owners who experience engine trouble.

OBD is usually connected to the console, so the port can be easily diagnosed and data can be read. But OBD2 is remotely used for diagnostics and reads data via a Bluetooth connection, which makes it easier to diagnose issues remotely if you have a vehicle with an OBD2 system.

Main Differences of OBD and OBD2

  • OBD is connected to the console of a vehicle, while OBD is remotely connected.
  • OBD was used in the early years of the vehicle manufacturing industry.
  • OBD2 was recently introduced in the early 90s.
  • OBD offers decent diagnostic capabilities, while OBD2 features better-messaging formats and signaling protocols.

Noticing the main differences between these versions of OBD in most cases can be very challenging because in some cases the differences may not exist at all. This is usually the main reason why some consumers searching for the latest version of OBD2 can end up purchasing a scan tool with features that are only found on OBD.

A Closer Look at Minor and Major Differences between both Technologies

OBD2 is just a replica of OBD, with the main different noted in terms of the coding scope. Some small, yet notable differences include the production date, and a difference in efficiency and speed.

As we have mentioned, the first generation system was called OBD. The second generation system that was released in 1996 is called OBD2. Another noticeable difference with the new generation systems is the faster baud rate.

With OBD, each manufacturer used their own definitions and codes for identifying issues in a vehicle’s computerized engine management system. This made it difficult for mechanics to repair and service different brands of vehicles.

The OBD2 common or generic code definitions were created in order to identify all basic emissions related issues regardless of whether the vehicle is domestic or foreign and regardless of the vehicle’s make or model.

The standardization helped to simplify the diagnostics process and the tools that work with the control module.

What are Set Trouble Codes?

OBD2 trouble codes consist of an alpha character that’s followed by a four digit description. The alpha character used indicates the part of the vehicle that’s experiencing issues.

The body features airbag system codes that include clock spring, crash sensors, in addition to the airbag deployment module.

The powertrain includes the engine and transmission codes, which is the most common system that will set trouble codes. The first digit of the trouble code will denote the origin of the code.

Generic Codes used

Generic trouble codes are the same trouble codes that are used for every vehicle regardless of make and model.

A generic P0301 code indicates that a cylinder is misfiring.

If the first number in a trouble code is the number one, this can indicate a code that’s manufacturer specific.

These diagnostic trouble codes are part of the manufacturers influenced diagnostic software and vary among car makers.

The second digit in the diagnostic trouble code identifies the system where the malfunction is occurring.

The number four is used for the fuel vapor recovery system while the number three is used for the ignition system.  The last two digits in a diagnostic code will correspond to specific codes.

OBD2 and OBD are similar in that both of these systems check actuator circuits and sensors for shorts and high resistance in out of range values.

The failure limits for OBD is much more forgiving considering a component or circuit must completely fail before the check engine light turns on or a trouble code is stored.

OBD2 uses a series of diagnostic tests that provide performance evaluations on emission related computer components and sensors. Even though the circuit may still be operating, when a monitored circuit fails to meet minimum standards the check engine light can be turned on.

OBD2 Sensors and Subsystems

The powertrain control module will trigger the check engine light, notifying the driver and storing the trouble code in order to aid in the diagnostics process. This ability makes it possible for problems that are emissions related to be corrected and identified before any excessive amount of pollutants are discharged via the tailpipe.

Of course, this will only work if the driver pays attention to the check engine light and takes their vehicle in for repairs.

The OBD2 can monitor fuel control, misfire detection, catalyst efficiency, exhaust gas re-circulation, heating circuits that warm the cold O2 sensors and oxygen sensor data. Vehicles with climate control will also report back to the control module.

Once you pull a trouble code, the fastest way to a successful repair is following a diagnostic chart, which can be found online on OBD and OBD2 specific websites and seeking the help of a professional mechanic if the repairs needed are beyond your skill level.