Cruise Control
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.
On models equipped with cruise control, the system is operated by the ECM. ECM receives inputs from Vehicle Speed Sensor (VSS), servo diaphragm position sensor, cruise control switch and brake release switch. Based on these inputs, ECM controls position of cruise control stepper motor. ECM prevents system engagement at speeds of less than 25 MPH. ECM is not serviceable; if defective, it must be replaced. A system fault is stored as a DTC in ECM memory.