Diagnostic Aids
WARNING: This page is about a different car, the 2003 GMC Yukon XL, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
DTC P1860 defaults to an elevated line pressure condition which may result in partial TCC apply. This may produce an idle surge that could stall the engine.