I have an 01 ram 5.2/automatic with 130K miles and the tranny just started not shifting outta first gear until 4000 rpms. After that shift it seems to work okay though. I ordered the governer pressure solenoid and sensor to change but started wondering if the problem could be related to my truck pcm instead? It has the dreaded P0601 code which means the pcm needs to be replaced, but has been like that for quite awhile and never given any trouble. Am i on the right track with changing the sensor/solenoid or do any of you think it may be just the trans itself or maybe my pcm?

thanks for any help!