Action Taken When the DTC Sets

WARNING: This page is about a different car, the 2008 Pontiac G5 and 2008 Chevrolet Cobalt. However, it is still accessible from the selected car via links, so may be relevant.

DTC P0068 is a Type A DTC.
DTC P0121 is a Type B DTC.
The ECM commands the throttle actuator control (TAC) system to operate in the Reduced Engine Power mode.
A message center or an indicator displays Reduced Engine Power.
Under certain conditions the ECM commands the engine OFF.