An Introduction to OBD II An Introduction to OBD II

An Introduction to OBD II

Learn how it monitors engine performance, detects issues, and helps with vehicle maintenance and repairs.

Hello and welcome back.  Today we are going to explore the world of diagnostics.  Today we hear the term OBD II a lot.  Of course, that’s an acronym, so let’s find out exactly what it stands for.  

OBD II stands for onboard diagnostics version 2.  Since it is version 2, there must have been a one. Looking back into a little history will tell us that onboard computer systems actually started in 1968 with VW including an analog system on their fuel injected type three models.  It lacked any diagnostic capabilities but did usher in the world of computer controls. 

In 1975, Bosch and Bendix debuted their fuel-injection systems to help with tailpipe emissions.  While these were analog systems, they started to include some very rudimentary diagnostic capabilities.  Finally in 1988, CARB required that all vehicles sold in California have some basic on-board diagnostics. This capability is not standardized or consistent between brands. 

In 1994, OBD II was created for CARB sales and then in 1996 it was made a requirement for all vehicles sold in the United States.  The significance of this event is that the SAE developed a standard protocol for transmitting this data and a standard plug that we are all familiar with today.  This also includes a standardized set of trouble codes across manufacturers for diagnosing issues. 

We are all familiar with the OBD II plug on vehicles.  The universal thing about these is they all use the same connector and read out the same codes regardless of the vehicle it is being used on.  Today the most common tool used is the familiar code scanner.  These vary in price and capabilities.  Some merely read out the trouble code and require the user to identify the proper repair.  The more sophisticated tools include further diagnostic capabilities.  The most sophisticated tools will allow pinpoint testing of individual circuits and step by step procedures to lead to the proper fault. 

Today’s technological advances have created all-new opportunities for OBD II.  Tools no longer must be plugged into the port with a wire connecting them.  Bluetooth connections allow for remote tool use with just a small transmitter plugged into the vehicle.  Many other uses for the port have found their way into use.  Insurance companies can monitor insured driving habits, performance companies can use the port to alter performance programs within the ECM, and even theft-deterrent companies can use this port to locate the vehicle. 

When you are assisting your customer with an OBD II issue, it is especially important that both you and the customer realize what capabilities you are using.  If they are using a reader, the actual diagnosis is still up to them.  Simply throwing parts at a code is not a recipe for success.  Further guided diagnosis is suggested for proper repairs.  Do not get caught suggesting the replacement of a component and then be faced with a return issue with your customer. 

That’s all for today and thanks for being with us.  

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