Circuit Description
WARNING: This page is about a different car, the 2002 GMC Cab & Chassis Sierra and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The 1-2 shift solenoid valve controls the fluid flow action on the 1-2 and the 3-4 shift valves. The 1-2 shift solenoid valve is a normally-open exhaust valve that is used with the 2-3 shift solenoid to allow 4 different shifting combinations.
When the PCM detects a 2-2-3-3 gear ratio, then DTC P0751 sets. For Federal emissions vehicles, DTC P0751 is a type "C" DTC. For California emissions vehicles, DTC P0751 is a type "B" DTC.