Diagnostic Aids
WARNING: This page is about a different car, the 2002 GMC Yukon XL, 2002 GMC Sierra, 2002 Chevrolet Suburban, and 2002 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
Inspect for improperly wired after-market equipment.
DTC P0748 defaults to an elevated line pressure condition which may result in TCC partial apply. This may induce idle surge and engine stall.