Diagnostic Trouble Codes (DTC'S)
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 GMC C3500 HD, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Sensing & Diagnostic Module (SDM) provides a record of each DTC, stored according to type. SDM performs diagnostic monitoring of SIR system electrical components and sets a DTC when a malfunction is detected. Current DTC's are stored in SDM and are erased when fault is corrected. Current DTC's can be read using a scan tool such as Tech 2.