The idle air control valve is located on the throttle body (the top sensor). Remove the black Vortec plastic cover and looking at the throttle body you will see 2 sensors with plugs attached on the right (drivers) side... one on the top, one on the bottom. The top is the IAC (idle air control) and the bottom is the TPS (throttle position sensor). Both have 2 bolts to remove in order to take them out which require a TORX 20 (T-20) screw head.
on the throttle
The 2006 Chevrolet Silverado-2500HD has 16 valves.
The 2006 Chevrolet Silverado-1500 has a V6 engine.
The 2006 Chevrolet Silverado-1500 has 12 valves.
The 2006 Chevrolet Silverado-2500HD has a V8 engine.
The 2006 Chevrolet Silverado-2500HD has overhead valves (OHV).
The 2006 Chevrolet Silverado-2500HD is a gas-powered vehicle.
The 2006 Chevrolet Silverado-1500 has overhead valves (OHV).
The 2006 Chevrolet Silverado-1500 is a gas-powered vehicle.
The 2006 Chevrolet Silverado-1500 has a 5-speed manual.
The 2006 Chevrolet Silverado-2500HD has a 5-speed manual.
The 2006 Chevrolet Silverado-1500 runs on regular unleaded.