Circuit/System Description
WARNING: This page is about a different car, the 2017 GMC Yukon XL, 2017 GMC Yukon, 2017 Chevrolet Tahoe, 2017 Chevrolet Suburban 3500 HD, and 2017 Chevrolet Suburban. However, it is still accessible from the selected car via links, so may be relevant.
The shift solenoid 1 is part of the control solenoid valve assembly which has no serviceable parts. The control solenoid valve assembly is attached to the lower control valve body. The solenoid operates by the Transmission Control Module opening or closing the ground circuit. With the solenoid circuit grounded (solenoid on), the internal plunger and metering ball block the exhaust fluid creating signal fluid pressure. The signal fluid acts against the clutch select valve 2 to overcome the valve spring force moving it to the apply position, allowing the shift. The shift solenoid 1 is commanded ON in Park, Reverse, Neutral and Drive 1 Engine Braking, and commanded OFF in Drive 1 - 6 gear ranges.