So soon after I got an error code for the oxygen sensor, which I replaced and is now fine, I got a P0622 Generator F-Terminal Circuit error. This results in the battery light going on about 30-45 seconds after the vehicle is turned on and it stays there until its turned off. I have since replaced the battery (Bosch Premium) and the alternator (OE GM/AC Delco) but the battery light and error code still come up (even after clearing the code). The truck otherwise starts and drives perfectly fine, but the battery light going on is annoying. I had two different shops check both the battery and the alternator to make there were no issues, and in both cases, they checked out perfectly fine. Could it be some sensor or fuse? Not sure what to check next...

 

Replace the battery terminals and check ALL your ground wires.

 

https://www.troublecodes.net/pcodes/p0622/ read it it is very informative and explains the reasons that trigger the code. it can be as simple as bad battery connectors or as bad as a bad PCM