See also:

Cellular and GPS Antennas
Avoid placing items over or near the antenna to prevent blocking cellular and GPS signal reception. Cellular reception is required for OnStar to send remote signals to the vehicle. ...

2011 GMC Sierra 2500HD Review
The "professional grade" brand unveiled the 2011 GMC Sierra Heavy Duty lineup at the 2010 NTEA Work Truck Show. Most of the technical specifications of GM's HD pickups are identical, but ...

Engine Fan
If the vehicle has a clutched engine cooling fan, when the clutch is engaged, the fan spins faster to provide more air to cool the engine. In most everyday driving conditions, the fan is spinning slo ...