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:
Emergency towing
See page 282 for more information. ...
Approach lighting
Approach lighting is activated by pressing the
approach light button on the remote key (see
the illustration on page 58).
When the function has been activated, the
parking lights, indicator lig ...
Accessory installation
We strongly recommend that Volvo owners install only genuine, Volvo-approved
accessories, and that accessory installations be performed only by a trained
and qualified Volvo service technicia ...
