Circuit/System Description - Solenoid Valves
WARNING: This page is about a different car, the 2024 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
The solenoid valves receive 12 volts from a high side driver internal to the TCM. The high side driver protects the circuit and components from excessive current flow. The TCM supplies a control circuit to each of the solenoid valves. Each control circuit has a low side driver. Control of the On/Off solenoid valve is accomplished by turning the low side driver On or Off. The TCM controls the current to the pressure control solenoids by controlling the amount of time the low side driver is On and Off.