OBD, or on-board diagnostics, is a computer technology that monitors a vehicle’s emission control system and other key engine parts to ensure they’re working properly. When a vehicle’s on-board computer detects an emission problem, it turns on a dashboard warning light to alert the driver, much like the way the oil light appears when a vehicle is low on oil. The OBD system can detect problems drivers do not.
Newer vehicles operate cleaner due to improved technology and sophisticated emission control
systems, but these systems must be in proper working order for the vehicle emissions to remain low. When an engine is not running as designed, performance is lost, fuel is wasted and air pollution increases. By detecting emissions control deterioration and/or failures, and alerting the driver to the need for attention, vehicles can be properly serviced before more serious problems develop.
The DEQ uses the OBD system to test the following vehicle types:
- 1996 & newer gasoline powered vehicles up to 8,500 lbs (GVWR)
- 2013 & newer gasoline powered vehicles greater than 8,500 lbs (GVWR)
- 1997 & newer diesel powered vehicles up to 8,500 lbs (GVWR)
NOTE: GVWR stands for gross vehicle weight rating. Some older vehicles may have a similar computer system, but the connections and problem codes may be different.