Threshold to use tow haul mode?

[Snakebitten]

He's mastered the OBDLink App!

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[turbopilot]

Engine Coolant Loop

@Snakebitten what manual are you pulling that documentation from and where can I get it?

 

[turbopilot]

What app are you using here? I dont have a PB but a 5.0 stx and have tried and tried to see my trans temp using torque and obd fusion. I cannot find a pid formula to add the temp myself.

OBDLink. See this thread.

 

[turbopilot]

@Snakebitten likes to go into the specifics of the various loops, perhaps he knows if there's any aux coolant pumps. There's one in the trans, haven't seen anything for engine's cooling side of things. The PB's batt / DCDC / motor inverter have their own low pressure coolant loop.

My mach-e has 4 coolant pumps on, all electric of course.

There are SAE PIDs that support turbine inlet temperatures but apparently not supported by Ford.

 

[HammaMan]

The only electric engine coolant pump that I know of is in the HVAC loop.

There is an aux coolant pump connected to the heater core AND the turbos! What info do you have on that snake? Item 13 in the diagram

 

[Tomatoboy]

Looking for feedback on when to engage tow haul mode.

Anytime I’m towing I have it engaged. How about when hauling stuff in the bed. Do you engage it when you hit a percent of max payload, when you hit a round number on weight, truck drive feel?

Curious what the best practice is for enabling it for hauling. Thanks.

I’ve never seen firm printed guidance from Ford about a payload threshold. I use tow/haul whenever I’m towing *anything* and whenever my payload is ~75% or more of rated payload. I base that on the logic that I want the altered shift and TCC lockup strategy in that mode, among other things.

 

[Snakebitten]

There is an aux coolant pump connected to the heater core AND the turbos! What info do you have on that snake? Item 13 in the diagram

I've never seen anything in the Factory Service Manual related to engine coolant pumps other than the two referenced in my earlier post.

There are 2 electric water pumps in the High Voltage coolant loop that look identical to the heater core electric pump. All 3 appear to be located in the same vicinity in the engine bay.

I guess it's possible that Ford plumbed the heater core electric pump to feed the turbos, but that would mean the Powerboost turbos are plumbed differently than the non Powerboost 3.5 Ecoboost. I have never seen evidence of that. In fact, the diagram above for the engine coolant loop includes the same type Turbo inlet and outlet coolant "tubes" that connect to jiffytite fittings in the engine block, that Ford has been using to cool 3.5 Ecoboost turbos since 2011.

14, 17, 24, 25

 

[Steve Feldkamp]

That sounds reasonable but watching the real time temperatures in both modes I have not seen any meaningful differences. Transmission temps seem to stay in a very narrow band of 210F to 220F with any outside temperature towing my Airstream. Here is a screen shot at 95F outside air temperature crossing the divide near Grants, NM.

What is that picture of?

 

[redline]

I just got done a 3000km trip hauling my 7500lbs fully loaded trailer in the rocky mtns , all of it in tow mode, the truck locked out 9 and 10 when going into tow mode, I have never used tow mode with just stuff in the bed.

 

[Bugzuki]

My experience is from a trip from Mesa AZ to Flagstaff in May 2022. It was 90+ degrees. We had the truck a couple months and we're pulling our 5000 lbs travel trailer. I was irritated that it wasn't going into Regen mode going down hills. So I was driving in normal or Eco mode. Just outside Flagstaff the truck went into limp mode and I had like 15 messages flashing on the dash.

The Ford dealership shop was already closed but the sales lot said we could camp there over night. We went in my wife's car to get dinner and get a nail fixed. When we got back a could hours later, I went to reposition the truck and camper. It started and everything was normal.

So, I put it in tow/haul mode and we continued our trip to Reno with no other issues.

Turns out I overheated every module. Luckily for us it didn't destroy anything. It ruined our ideas of checking out Flagstaff, but the truck has been fine ever since.

I did put it in tow/haul when full of gravel. But if I am pulling my 16 foot car hauler empty I don't put it in tow mode so I can get slightly better gas mileage. But if I have anything on it I put it in tow mode. No more overheating for me, PLEASE.

 

[Jracing123]

That sounds reasonable but watching the real time temperatures in both modes I have not seen any meaningful differences. Transmission temps seem to stay in a very narrow band of 210F to 220F with any outside temperature towing my Airstream. Here is a screen shot at 95F outside air temperature crossing the divide near Grants, NM.

What app are you using to see transmission temperature, ? thanks

 

[Snakebitten]

OBDLink app

 

[RickBullotta]

I have found with flat terrain, no wind or tailwind, my PB seems to do very well towing a 7,100 Airstream trailer in Normal Mode with a slight increase in milage. With head winds and/or mountainous terrain, I go to Tow/Haul mode. Make sense?

I'd be cautious doing that - I have a feeling that having the drivetrain switch into electric only mode when hauling 7000 pounds is probably not good for it. I've forgotten to put it in Tow/Haul mode for brief periods when hauling our 5000 pound Airstream without incident, but I always intend to use Tow/Haul mode.

But if I need to school a RAM hauling a trailer too, Sport mode it is. <kidding>

 

[imnuts]

I've had no issues with short (2-5 mi) trips with a lot of weight in the bed using normal mode. After a short distance, I feel like the truck realizes it has a load and starts shifting a little differently on its own. Tow/Haul worked more seamlessly, but I feel it's better suited for long trips with lots of hills.

 

[Grafx36510]

I recently used tow/haul mode for a couple of work deliveries with around 1100 lbs in the bed. It drove like a champ on the moderately hilly 55mph route.

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