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:
Towing a trailer
The maximum weights recommended by Volvo
for trailers with brakes are shown in the table
below.
Recommended hitch tongue load: not more
than 10% of the trailer's weight. The trailer
load should ...
Lever positions
Turn signals, lane change
position
Turn signals, position for
normal turns
High beam flash
Toggle between high and low
beams,
Home Safe lighting ...
Crash mode
Driving after a collision
If the vehicle has been involved in a collision, the text Safety mode See manual
may appear in the information display. This indicates that the vehicle's functionali ...
