robi.robison@verizon.net

Thanks all. I'll replace the secondary fuel filter. And Tranny-codes were checked -- no codes other than normal. Robi

Cummins 350 HP ISL Engine with Allison 3000 MH 6. The control panel has the MODE button...but I've not used it or changed any setting from that of the factory. We put 20,000 on the Diplomat with the cruise control working fine. Then the 6th-to-5th shifting (when initiating the cruise control) became intermittent. It seemed that stopping and turning-off the engine (like: at a rest stop) would "reset" something, and the cruise control would work fine for a while. But here of late, the 6th-to-5th shift happens all the time when turning the CC on.

My 2004 Monaco Diplomat Cummins/Allison recently began the following: When on level Interstate traveling about 60 or 70, the tranny is in 6th gear. Boost is low. We're rolling nicely. Then I apply the cruise control and the tranny downshifts to 5th gear and STAYS in 5th gear. Canceling or turning-off the cruise control ... and the tranny shifts into 6th gear. Anyone else experience such a problem?