While towing a 12,000-13,000# trailer we will experience a sudden "hesitation" or momentary loss of power. As another poster described it, it's like suddenly being hit from behind. It's always at speeds between 50-65 and while on a slight or moderate incline. Cruise control may be engaged, or I may be applying a light acceleration. It does not happen under heavy acceleration (I may experience a hard shift then, but I think that's normal). It usually happens when tow/haul has [u]not[u] been selected, but has happened infrequently when in tow/haul. The govenor pressure sensor and solenoid were just replaced, but that didn't seem to help any at all. My mechanic reports that diagnostics indicate the Throttle Position Sensor is OK. The check engine light has not come on and it's not throwing any codes, so if there is anything wrong it must not be monitored by the computer. I read about the APPS reset, and will probably attempt that in the next day or so to see if it helps. After reading some of the threads, I'm beginning to wonder if anything really is wrong, or if it's just the nature of the beast.

At very light throttle pressure, when the trans upshifts from 1st to 2nd and sometimes from 2nd to 3rd, it cant't make up its mind which gear to be in, so it shifts up then back down very quickly then back up. I have learned to either lighten up more or accelerate a little faster so my trans won't do it. I believe DTT transmission service has a fix for this.