4th Clutch Releases
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
If the transmission is operating in Fourth gear when an electrical malfunction occurs, the shift solenoid 1 defaults to its normally closed state (OFF) and the 4th clutch is released. Refer to EVT Mode High - From Drive Range 4th Gear for a complete description of 4th clutch release.