Circuit/System Description

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The clutch pressure control (PC) solenoid 4 is part of the control solenoid valve assembly which has no serviceable parts. The normally low PC solenoid 4 regulates and directs oil pressure to the 2-6 clutch regulator valve. Increasing PC solenoid 4 pressure, increases pressure to the 2-6 clutch regulator valve. The transmission control module (TCM) varies the current to the PC solenoid 4 through a low side driver. Increasing the current to PC solenoid 4 increases oil pressure by closing OFF the solenoid exhaust port. Decreasing the current to PC solenoid 4 decreases oil pressure by opening the exhaust port. PC solenoid 4 power is supplied by the TCM through a high side driver (HSD). The HSD protects the circuit and components from excessive current flow. If excessive current flow is detected, the HSD will turn OFF. When the fault is corrected the HSD will reset.