I don't know about the code, but everyone with an rfe should watch these videos. The valve body is worthwhile upgrade. I have no comment on brand, just watch these and research options on your own...
my brother in law went through three tranny's before buying a manual, cummins 3500. He didn't know about the Upgrades, maybe they would have saved his truck, dunno. The dealer gave him 1 oem replacement, and he paid for two, because he had a business and towed heavy they weren't on tline for it. Valve body plate and tune, and mise well get new pistons and springs when the VB is down. Ask about GM solenoid upgrade.