Skip the auto shop - Our mechanics make house calls

Do All Vehicles Have an OBD System?

CarDash

Today’s cars are equipped with sophisticated technology. The OBD system (on-board diagnostics) is actually advanced enough to monitor several critical systems on your vehicle and warn you when something starts to go wrong, which can prevent serious damage in the long run.

Not all cars have an OBD system

OBD has been around for a long time, but not all vehicles have this system. OBD I, the first version, was introduced as early as the 1960s, but it wasn’t mandatory on all cars. Some automakers included it from the beginning, but others didn’t adopt it until later on.

OBD II came along later, but it was not made mandatory until 1996. From that point onward, all vehicles sold in the US were required to have an OBD II system. This meant that all vehicles had the same type of connector located somewhere under the dash, and that most of the trouble codes were standardized. Note that not all trouble codes are standard or open for access. Some are automaker-specific and cannot be read without an advanced scan tool (a consumer-grade code reader will not do this).

OBD II also surpassed OBD I in other ways. For instance, OBD I systems would only turn on the Check Engine Light after a failure. OBD II systems are able to monitor gradual deterioration of a system and turn on the Check Engine Light before a failure.

Unlike OBD I, which was a general monitoring system for vehicles, OBD II systems are highly focused on emissions and related systems. While the OBD II system also monitors engine and transmission performance, emissions control is the primary reason it was instituted.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...
P2422 OBD-II Trouble Code: Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed
Diagnostic Trouble Code (DTC): P2422 P2422 code definition Evaporative Emissions Control System (EVAP) Vent Valve Stuck Closed Related Trouble Codes: P2441: EVAP Vent Valve Stuck Open EVAP trouble...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...


Related questions

Q: What Is the OBD II System on My Car?

OBD II is an abbreviation of on board diagnostic system generation two. The system was brought into service in the vehicles of model year 1996. The system was put into all vehicles to monitor the operation and control the engine...

Q: ABS light on dash board

Hello. Since this could be a variety of potential issues, I would recommend hooking the car up to an OBD scanner to download any trouble codes that may have registered as a result of the light coming on. I would...

Q: OBD-II failed for smog check

Unfortunately without more information as to why your Toyota Corolla did not pass the emissions test, it is difficult to determine the cause for the failed smog check. Provided that the ODB2 port itself has power and is allowing the...