Extra fuel tank sensor in HD Tow Package Wiring Harness

[konacq]

I am a brand new poster to this forum, but I have visited here many times. First, I want to thank everyone for being so helpful - I was a very informed Ford Expedition consumer, thanks to this and other forums. I could not have accomplished my recent Expedition purchase as confidently (and successfully) as I did without your help. In fact, I knew so much more about the Ford Expedition than the Ford dealership salesman and manager that I felt embarrassed for them - and in the end, my knowledge advantage cost them. They should read this forum!

I recently purchased a used 4X4 2006 Ford Expedition at a Ford dealership. I need to tow a 6000 lb (dry weight) trailer I just bought, and I want to respect the 20% tow capacity margin rule. I am figuring the trailer all up might weigh as much as 7,000 pounds under tow, so I was looking for a vehicle that can pull at least 8,500 lb. I had narrowed my selection down to an Expedition or a Toyota Sequoia, but the Expedition won on price.

The Expedition I looked at did NOT have the heavy duty trailer package (the salesman lied and said it did), and I negotiated with the sales manager to include the Ford factory installed HD tow package as an upgrade at no extra cost to me. I don’t think the manager understood what he was getting into, because when it came time to write up the contract, I specifically wrote in all the things that were included in the heavy duty towing package (thanks again, guys!) He sweated for a long time, but finally agreed to install the HD radiator, HD transmission cooler, and the brake controller wiring harness (the car already had the V-5 rated Class IV hitch) at no extra cost.

I think the sales manager would have rejected my offer had he known how much work it was going to be. The HD radiator and HD transmission cooler was no problem, but the Ford dealership service manager told me it took several of his technicians a day-and-a-half to install the factory wiring harness! Evidently they had to remove the gas tank and install additional sensors (included in the wiring harness package) in the gas tank as part of the Ford factory wiring harness installation. The good news is, because I had this upgrade done in 2011, I now have the second gen wiring harness, with both the 4 and 7 pin connectors.

Does anyone know why there would be additional sensors in the gas tank for an HD tow package wiring harness? What do they measure? What would they be connected to - something must be monitoring these new sensors, and it is obviously not the brake controller. How will these additional sensors affect the performance of the vehicle?

Konacq

 

[tojohnso]

I came across this from a Google search and see no one answered your question. Unfortunately, I do not know the answer to the question of why the extra fuel sensors. Maybe someone will see this and have the answer?

 

[Bowesmobile]

I can not fathom why they would need extra sensors in the fuel tank. I'm a mechanical engineer and my only guess as to why could be to do with the Automatic Braking system they started putting on SUV's. So that in the event you take a corner too fast it applies the brakes to keep you from rolling over. Possibly it uses the gas in the tank as a level to check pitch and yaw? But remember this is only a guess.

 

[BIGRED03]

I think I know why there is an extra sensor. Ford and other automakers ship to convertors that stretch cars and trucks into those long limos you see around town. I believe that this could be for a relocation and maybe and aux fuel tank. I do not think I want to know the mileage of a stretch Expedition, 7, 8 maybe 9? Just a thought.