My 2001 3500 w/75000 miles just had a similar problem, when I came up to a stop, the trans would downshift normally, just before the truck came to a complete stop it would upshift into a higher gear and stay there. Manually pulling the selector lever into 1 would allow the truck to start out in first, then it would upshift normally once placed back in drive. I scanned the truck while driving with a Snap On MODIS scanner and the scanner showed the truck downshifting into 1st but when the truck upshifted just before stopping, the ECM still thought it was in 1st. (It also never lit the check engine light either) ANYWAY... ..... I replaced the transducer and the solenoid along with the filter and now the truck is fine. It's an easy (but messy) job and it only took about 30 minutes without a lift. The parts listed at $65. 20 for the transducer and $112. 00 for the solenoid ( cost me $46. 92 and $80. 64 at 10% over dealer) plus a pan gasket, filter and fluid (ATF+4). I'm kinda glad that It acted up when it did as it would have been a real pain if it acted up while towing a trailer. Hope this helps, John