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.
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Environment
Good environmental protection is one of Volvo's cornerstones. All of the
engines available in the all-new Volvo S80 are outstandingly economical, given
their performance.
The manual diesel engin ...
Call volume
Call volume can be only be adjusted during a
call. Use the buttons in the steering wheel keypad
or the infotainment system’s VOL control. ...
Under the glove compartment
Fold aside the upholstery covering the fuse
boxes.
1. Press the cover's lock and fold it up.
2. The fuses are accessible.
Positions-fuse box A
Positions-fuse box B
...
