Circuit Description
WARNING: This page is about a different car, the 2007 GMC Sierra and 2007 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The 3-2 shift solenoid (SS) valve is a normally-closed, 3-port, ON/OFF device that controls the 3-2 downshift. The solenoid attaches to the control valve body within the transmission. The solenoid receives voltage through the ignition voltage circuit. The transmission control module (TCM) controls the solenoid by providing a ground path on the 3-2 shift solenoid valve control circuit. During a 3-2 downshift, the 2-4 band applies as the 3-4 clutch releases. The TCM varies the timing between the 3-4 clutch release and the 2-4 band apply depending on the vehicle speed and throttle position.
When the TCM detects a continuous short to voltage in the 3-2 shift solenoid valve control circuit, then DTC P0788 sets. DTC P0788 is a type A DTC.