Secondary Air Injection System

My check engine light is on. The guy at the parts store says that the error code is for the secondary AIS and that the pump is accessable through the passenger side rock sheild over the tire. I thought smog pumps were belt driven. Anyone know exactly where this air pump is on a '99 Bravada?

It is likely that your AIS air pump runs for only a minute or two after you start the car, so it is electrically driven rather than running all the time on a belt. You will likely find that it looks a lot like the motor and fan from your vacuum cleaner.

The parts store guy should be able to show you the “exploded view” drawing with part identifications. Simply ask.