Diagnostic Aids

WARNING: This page is about a different car, the 2003 GMC Sierra, 2003 GMC Cab & Chassis Sierra, 2003 Chevrolet Silverado, and 2003 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Refer to Tramsmission Fluid Pressure (Tfp) Manual Value Position Switch Logic for the normal range signals and the illegal of 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.