Circuit/System Description

WARNING: This page is about a different car, the 2008 GMC Yukon XL, 2008 GMC Yukon, 2008 Chevrolet Tahoe, 2008 Chevrolet Suburban, and 2008 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

The 1-2 shift solenoid (SS) valve and the 2-3 SS valve control transmission fluid pressure acting on the shift valves to position the valves for the appropriate gear. The 1-2 SS and the 2-3 SS valves are located on the control valve body. The transmission control module (TCM) commands the solenoid ON or OFF by switching the ground path. When the 1-2 SS valve or the 2-3 SS valve is commanded ON, the TCM senses low voltage. When the 1-2 SS valve or the 2-3 SS valve is commanded OFF, the TCM senses high voltage. The torque converter clutch pulse width modulated (TCC PWM) solenoid valve is a solenoid used to control the application and release of the converter clutch. When the solenoid is commanded OFF, the TCM senses high voltage. When the solenoid is commanded ON, the TCM senses low voltage.