DTC code P0601

I recently had code P0601 pop up on my truck listed above 1500 v8 gas, so I checked a few things, I had a couple loose battery connections so I tightened them up, next I reconnected my code reader to see if the code was still there and it is, the truck runs fine like usual, my code reader has a drive mode that will tell me rpm mpg etc, like a set of gauges. The truck seems to actually be getting better mpg than ever before, runs at normal temperature oil pressure and charge. I'm kind of perplexed now, not sure what to do next. I've done some research and that tells me it's not always the PCM. If you have any ideas, I'd appreciate it!

Thanks.