DTC P1845: Torque Limit Management: Description
WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
The ECM continuously calculates how much engine torque should be commanded for the given engine speed and throttle angle. The ECM then compares this commanded value to a maximum torque value that could be applied at that specific engine speed and throttle angle. DTC P1845 will set if the commanded engine torque for the given engine speed and throttle angle fall outside the maximum allowable limit for longer than 10 minutes. Under no circumstance should the commanded engine torque exceed the maximum allowable engine torque.