2012 GMC Terrain
SUV (automatic) has 165k Miles
Replaced the battery, Checked all Fuses and Spark Plugs, and the Fuel Pump seems to be working.
The Codes we received are P062F - Internal Control Module & P0420 - Catalytic System Efficiency Below Threshold
I have done some research and have found suggestions of replacing the ECM, but don't know if that is the route I should take.
P062F - Internal Control Module
the full definition is:
DTC P062F: Control Module Long Term Memory Performance
and you have to pay attention to which module the fault came from. ECM or TCM. You may need a better scan tool for that.
For now I would clear the codes and see if this one comes back. It might also be caused by problems with your charging system.
So before spending hundreds or thousands of dollars on new computer, do some diagnosis. get a free alternator/battery load test.
P0420 is covered in our FAQ
