Diagnostic Aids

WARNING: This page is about a different car, the 2006 GMC Sierra, 2006 GMC Cab & Chassis Sierra, 2006 Chevrolet Silverado, and 2006 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Transmission Fluid Pressure (TFP) Manual Valve Position Switch Logic for the normal range signals and the illegal or invalid switch combinations.
DTC P1810 can set from low pump pressure, a stuck pressure regulator, or unit refill from overhaul and pan removal.
DTC P1810 can be set by a slipping forward clutch, allowing a 2.08:1 ratio, reverse, when the manual valve position is indicated as D4.
DTC P1810 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.