Action Taken When DTC Sets

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Suburban, and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

The PCM will illuminate the Malfunction Indicator Lamp (MIL) during the first trip in which the diagnostic test has been run and failed.
The PCM will signal the IPC to turn ON the Service Engine Soon indicator.
The PCM will alternately disable two groups of four cylinders by turning OFF the fuel injectors.
The PCM will store conditions which were present when the DTC set as Freeze Frame and File Records data.