DTC P0961
WARNING: This page is about a different car, the 2007 GMC Yukon XL, 2007 GMC Yukon, 2007 Cadillac Escalade EXT, 2007 Cadillac Escalade ESV, and 2007 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
The TCM detects an internal electrical performance malfunction of the line PC solenoid control circuit and the actual line pressure does not equal the commanded line pressure for 300 milliseconds.