How do states use OBD II for emission inspections?

Many states connect a computer directly to a vehicle's OBD II system. The inspector can then read "faults." In some states, this type of inspection has replaced the tailpipe emission test.
See also:
Overhead courtesy lighting
The passenger compartment lighting is
switched on and off automatically when button
(3) is in the neutral position.
The lighting comes on and remains on for
30 seconds if:
• the vehicle is unl ...
Scroll/search forward and back
Press briefly on (2) to scroll between CD tracks/
audio files or to search for the next available
radio station. ...
Engine and cooling system
Under special conditions, for example when
driving in hilly terrain, extreme heat or with
heavy loads, there is a risk that the engine and
cooling system will overheat. Proceed as follows
to a ...
