Issues with Tow/Haul mode

Desert Captain wrote:

As noted above TH especially on an E-450 should be engaged virtually all of the time due to the weight and aerodynamics {or lack thereof}. What the OP described does not sound right and the suggestion to have the dealer reflash the ECM sounds like the way to go.

I have spoken with a couple of dozen folks renting C's and not one was ever given a syllable of instruction on using TH. This tells me two things, one; most of the folks renting them are blissfully ignorant of this function and two, most rental RV are slowly but surely cooking their transmissions, caveat emptor. :E

To be clear, my unit DEFAULTS automatically to engage T/H upon starting. CA, it seems, is doing itself and renters a favor in this regard and even reminding drivers with the sticker on the gear shift lever to keep it engaged for better fuel economy. Your points--and those repeated by others earlier--about keeping it engaged are appreciated. I failed to take into account the continuous load factor / added weight built onto the chassis. I'm getting the transmission fully serviced later this week and will definitely inquire about re-flashing the ECM. Thanks to you all who contributed to my education!