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 valve to allow for four different shifting combinations. The 1-2 shift solenoid valve attaches to the control valve body within the transmission. The ignition voltage goes directly to the 1-2 shift solenoid valve. The PCM controls the 1-2 shift solenoid valve by providing the ground path through the 1-2 shift solenoid valve control circuit (1222).
When the PCM detects a continuous open or short in the 1-2 shift solenoid valve circuit or the 1-2 shift solenoid valve, then DTC P0753 sets. DTC P0753 is a type "B" DTC.