Having a 1st-2nd shift problem with my truck. The truck has only 133,000 miles total with 34K on the transmission upgrades. The truck will shift down to first as I stop but it will shift back to 2nd if I release brake and creep forward at idle. It continues to shifts between 1st-2nd and 2nd-1st unless I bring the shift lever into Low then it holds. All up shifts when driving are normal. After my transmission upgrades I had a solenoid fail, the transmission would not shift down to first at stops. Solenoid was replaced and no further problems. Oil levels good, no burned oil transmission is serviced every 10K miles, pan dropped, filter changed and inspected for wear. I am also throwing the P1740 code more often then before. Can it be solenoid failing again?

Tony