Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2010 Pontiac G5 and 2010 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

DTCs P0601, P0602, P0603, P0604, and P062F are Type A DTCs.
The TCM commands maximum line pressure.
The TCM forces the torque converter clutch (TCC) OFF.
The TCM inhibits TCC engagement.
The TCM freezes transmission adaptive functions.
The TCM commands a soft landing to 2nd gear, except P0602.
The TCM commands an immediate landing to 2nd gear, P0602 only.