Is there a reason I have to turn off the trailer tow mode every time I start the truck

 

Probably some gas saving issue like my 2015 Malibu has with the auto stop/start engine device. It's easy to keep the motor running at a stop light. You just shift into neutral. Saves the torque converter from building up heat sitting there with the unit in drive (D) mode anyhow. Some of this new crap is pure-D overcomplicated junk., IMO

My niece has shelled out $3000 USD on her FoMoCo piece of garbage F-250 with the 6.7 liter diesel turbo and the A/C quit working after all that. They shoehorned that motor into that 4WD pickup with no room to spare. Now, I have to fix the A/C on a huge turbocharged diesel motor with the A/C compressor at the bottom part of her F-O-R-D complicated motor, as after all the work done,

It's got a leak somewhere, as it only worked for a week or two. Chevy did it right on my 1998 K-1500. The compressor is on top of the engine, where if I needed to, I could pull in a half an hour or less. No wonder I hate F'd up beyond all repair F-O-R-D's. I've only had to replace the low-side Schrader valve on my 23-year-old Chevrolet pickup truck.

 

the switch usually fail when the wires from the shifter break in a location under the steering wheel cover bezel. This ususally makes the switch inoperative...not on all the time. Might be worth a look to inspect the wiring and switch.

 

As tech2 suggested, this could be a problem with the wiring for the switch. Could also be the switch itself or a glitch in the BCM.

The switch receives a reference signal (I think 5 volts but I’m not sure) from the BCM and is grounded on the other side at point G201. The switch is normally open and closes when tow/haul mode is selected, so when the BCM detects the reference voltage is grounded it alerts the PCM/TCM via data.

The wires are easy to identify once the column shroud is removed - they run into the shifter column. If visual inspection doesn’t reveal any problems, you can temporarily disconnect the switch side of the circuit by unplugging it at the base of the column. If it’s still in tow/haul mode on startup, further diagnosis is necessary.

FYI the tow/haul mode doesn’t help save fuel. It prevents the transmission from shifting into overdrive to prevent damage to the transmission while towing.