You can learn about OBD II diagnostic systems and hold down car repair costs in two ways. After learning enough about the OBD II system you may decide to perform some initial diagnosis on your own. 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.

Some rare check engine light repairs may fall into a gray area that requires extended diagnosis. 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 objective of the monitoring system was to be able to detect when vehicle malfunctions caused emission levels to rise above 50%. Obd mandated standard repair and diagnostic procedures without the need for dedicated specialty equipment.

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. Besides enhancements to the computer’s capacities, some additional hardware is required to monitor the emissions performance closely enough to fulfill the tighter 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.

Was OBD I that bad

OBD I was the first generation of onboard diagnostics systems and was designed to monitor some of the vehicle’s emission control components. They are Mandated on vehicles from 1991 and up. OBD-I systems were not as effective as possible, because they monitored only a few of the components and were not calibrated to specific level of emission 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 age of the automobile is directly related to the difficulty in diagnosing the car problem.

The electrical wire harness and connectors that allow the many parts to talk to each other were mandated by the government to last for ten years or 100k 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.