What is OBD II and why you should you care. If your check engine light is on now or has ever come on in the past becoming familiar with the system has some advantages. Often this type of car repair can be complicated or technical and also very costly.
You can learn about OBD II diagnostic systems and hold down car repair costs in two ways. Learning about the onboard diagnostic system should give you enough confidence to perform the first steps for diagnosis yourself. Of course it will depend on your situation, but you might be able to perform some do it yourself auto repair of your own check engine light.
Secondly you will be able to negotiate and discuss the needed car repairs on an advanced level if you do decide to take the vehicle into a shop.
Sometimes a check engine light repair may not be straight forward and require more diagnostic time. A blank check to the car repair center could be the result unless you are educated about system operation.
OBD II is better
The onboard diagnostics generation II was developed in response to the federal government, along with the state of California to comply with their emission control system-monitoring standards.
The main goal of this system was to detect when engine wear or component failure caused exhaust emissions to increase by 50% or more. OBD II also called for standard service procedures without the use of dedicated special tools.
To accomplish these goals manufacturers needed to change many aspects of their electronic engine control systems. According to the guidelines of the OBD II mandate all automobiles should have a universal diagnostic test connector known as a DLC or data Link connector.
These connectors should be mounted in a standard location and must be located under the driver’s side dash of the vehicle, and it must be visible. A standard list of diagnostic trouble codes using the society of automotive engineers (SAE) standard J2012.
The OBD system must turn on the check engine light if the vehicle conditions would allow emissions to exceed 1.5 times the allowable standard for that model year. Additional hard parts where needed to work in conjunction with enhancements to the electronic control unit to meet the tighter specified mandates.
In most cases this hardware consists of additional heated oxygen sensors down stream from the catalytic converter to measure how it is doing at cleaning the exhaust.
Troubleshooting and diagnostic capabilities are built into the automobiles PCM to all components that will affect emissions output. All input and output devices are automatically checked out by a troubleshooting program or routine to confirm its proper function.
What about OBD I
OBD I was the first generation of onboard diagnostics systems and was designed to monitor some of the vehicle’s emission control components. Required on all 1991 and newer vehicles. Since OBD I systems only monitored a few sensors they did not do well in monitoring total emmission system performance.
OBD two was developed to address these shortfalls of its predecessor and has also allowed more accurate diagnosis by professional auto mechanics. The older the vehicle gets the more chance that you will see a check engine light come on. Often the complexity of diagnosis is related to the automobiles age.
The federal government mandated that the wiring harnesses and electrical connectors that allow the components to communicate be designed and built to last 10 years or 100,000 miles.
The further a vehicle gets away from this milestone, the more likely a hard-to-find electrical problem could develop. This is why I believe that learning car repair is a valuable skill set even if you do not plan to fix it yourself.
