Conditions for Setting the DTC: P2728
WARNING: This page is about a different car, the 2009 GMC Sierra and 2009 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The transmission control module detects an internal electrical performance malfunction of the clutch pressure control solenoid 5 control circuit when the actual pressure does not equal the commanded pressure for 5 seconds.