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:
Seat belt pretensioners
All seat belts are equipped with pretensioners that reduce slack in the belts.
These pretensioners are triggered in situations where the front or side impact airbags
deploy, and in certain impacts ...
Engine compartment, overview
The appearance of the engine compartment may vary depending on engine model.
Coolant expansion tank
Power steering fluid reservoir
Engine oil dipstick
Radiator
Filler cap for engine oil
...
Coolant
Location of the coolant reservoir
Normally, the coolant does not need to be changed. If the system must be drained,
consult a trained and qualified Volvo service technician.
See page 341 for inf ...
