Idle Control System
WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
For idle control system testing, perform related DTC testing procedure. See DIAGNOSTIC TROUBLE CODE DEFINITIONS
in SELF-DIAGNOSTICS - 6.6L SIERRA & SILVERADO - DIESEL article.