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How 4A mode works?

RocketFistMooga

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Does anybody know how exactly the 4Auto mode works? I thought that it sent power to the rear wheels and only engaged the front when slippage was detected. However, when in 4A my power distribution screen always shows power to all 4 wheels
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Does anybody know how exactly the 4Auto mode works? I thought that it sent power to the rear wheels and only engaged the front when slippage was detected. However, when in 4A my power distribution screen always shows power to all 4 wheels
I’ve noticed the same thing, but I can’t imagine it’s full time 4wd like that. It makes me wonder the accuracy of the display
 

imnuts

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In simple terms, it makes the 4WD system behave like an AWD system. It sends power where needed and only "locks" when wheel spin is detected.
 

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According to the most up to date information, that’s the old 4A. The new ones do it the other way around, more like an AWD and switch to RWD when it makes more sense; like in parking lots.

There’s several threads on the matter with some links to technical papers and automotive journals.

For such a complex system, Ford has been incredibly blasé regarding the matter.

There’s been several iterations since the 90’s. The basic concept is the same. It uses a clutch pack to simulate a center differential.

Has anyone seen a difference in MPG or handling in dry conditions when using 4A versus 2H on equipped trucks? If there’s not a noticeable difference, I’d just leave it on 4A and not worry about the power distribution screen.

Also has anyone noticed the screen change in use? I should have put mine on the other day while backing a trailer up an incline with surge brakes. Went from 2H to 2H with the locker engaged and then 4L as I was maneuvering.
 

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I've used 4A extensively in the last 3 F150's I've had.
2018, 2021, 2022

The only real difference that I know of is that this 2022 doesn't have IWE's so it seems to show less difference in fuel economy between 2Hi and 4A. Driven as closely the same as possible, on a daily commute that hasn't changed in 22 years, I get a variance of less than 1mpg.

I do get a drop in mpg in heavy rain, but I suspect that is rolling resistance? It can cost as much as 1mpg on the same 46 mile round trip.

My figures aren't based on a single day result because it wouldn't factor in variations in traffic or the luck of the red lights. Instead it's just me repeating over and over the same commute that I could do in my sleep. :)

I've wondered why my 2022 Powerboost dropped its EPA rating of 24mpg (2021 Powerboost) to 23mpg. I can vouch that there literally is about a 1mpg difference. Is it the IWE removal? (or at least some portion of the 1 mpg is the IWE removal?)

I have become so accustomed to 4A in tropical wet driving conditions that I would retrofit it to an XLT if I was to acquire one. I prefer the additional weighted feel to the steering, as well as the truck being well planted overall.
 

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Does anybody know how exactly the 4Auto mode works?
FWIW, following in italics is a verbatim excerpt clipped from the the Ford Workshop Manual (TCCM = Transfer Case Control Module):
_____________________________________

307-07A Four-Wheel Drive Systems
2022 F-150
Description and Operation Procedure
revision date: 03/24/2022

Four-Wheel Drive Systems - Vehicles With: 2-Speed Torque On Demand Transfer Case - System Operation and Component Description
......

In 4WD AUTO (4A), the TCCM continuously monitors conditions and driver input to send torque automatically to the front driveline by controlling the transfer case clutch, providing 4WD capability. The TCCM sends a duty cycle command to the transfer case clutch coil as a torque request based on combination of preemptive and wheel slip response algorithm. Preemptive response is based on steering wheel angle, vehicle speed, throttle positions and available powertrain torque. Wheel slip response is based on monitoring the average front and rear wheel speeds.

When 4WD is no longer needed (during cruising or steady state driving) system defaults back to RWD (rear wheel drive) mode by setting the duty cycle output to 0.

TCCM increases the duty cycle to prevent or control slip under any of the following conditions:

  • Slip is detected.
  • Heavy acceleration (throttle position).
  • Straight-ahead steering wheel angle.
TCCM decreases the duty cycle to prevent or reduce vehicle bind under any of the following conditions:
  • Low speed.
  • Low acceleration (throttle position).
  • Tight turn steering wheel angle.
The TCCM has a thermal hardware protection strategy which monitors the amount of energy going through the clutch. This strategy has 2 levels of protections:

AUTOLOCK: If the system is in 4WD 4H
[***] and TCCM detects driving conditions that require greater 4WD performance, the TCCM temporarily turns on 4WD (4H) from 4WD AUTO (4A) after detecting driving condition and informs the customer via the message center indicating 4X4 TEMPORARILY LOCKED. The 4WD system automatically returns to 4WD AUTO (4A) after the system no longer detects these driving conditions and informs the customer via the message center indicating 4X4 RESTORED.

POWERTRAIN TORQUE PROTECTION: If the system is in 4WD AUTO (4A) and TCCM detects excessive stress or high energy going through the clutch (clutch is slipping excessively while the system is commanding max clutch torque), clutch output will be turned off and message center indicates 4x4 TEMPORARILY DISABLED. When the system had the ability to cool off, 4x4 operation will be automatically restored.

NOTE: The 4x4 Temporarily Disabled message can be dismissed by the customer however it's advisable to let the TCCM clear the message itself, which indicates that the 4x4 system has resumed normal operation.
.....

_______________________________

[***] NOTE - I believe that the term "4WD 4H" used here is a typo in the WSM text and should be "4WD 4A".

I suggest that the pictorial power distribution display simply isn't programmed with the sophistication required to reflect the sophistication of the actual moment-to-moment driveline behavior / status when in 4A mode. Yeah, that's a bit cheesy (and maybe a bit lazy on Ford's part, it would seem that the duty cycle commands from the TCCM could be used for the purpose of altering that display image to reflect what's really going on) but that display has nothing to do with the actual functioning of the system. On the other hand that might be intentional to prevent folks from freaking out when they see how little time is actually spent with power directed to the front wheels when in 4A mode (;)).
 
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Buyer2021

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According to the most up to date information, that’s the old 4A. The new ones do it the other way around, more like an AWD and switch to RWD when it makes more sense; like in parking lots.

There’s several threads on the matter with some links to technical papers and automotive journals.

For such a complex system, Ford has been incredibly blasé regarding the matter.
Please note the revision date of the Ford WSM excerpt in the previous post (03/24/2022) noting that each individual section of the WSM carries a different revision date based on when that specific section was revised.

That system operating description hardly strikes me as "blasé" on the part of Ford, the WSM is available online for a very nominal fee ($20 for 72-hour access) to anyone who really seeks authoritative info on these vehicles (and it is constantly updated as appropriate).
 
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wessermgm

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When it rains, I am in 4A. There is nothing that makes me more in control than 4A on an F150 on wet pavement.
 
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Pedaldude

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That system operating description hardly strikes me as "blasé" on the part of Ford, the WSM is available online for a very nominal fee ($20 for 72-hour access) to anyone who really seeks authoritative info on these vehicles (and it is constantly updated as appropriate).
The fact that this information is buried in the workshop manual shows Ford’s disinterest in the system.

Someone shopping for a vehicle shouldn’t have to be burdened with taking such a deep dive to find the answer for such a simple question. I’m not saying that they should be like Subaru and never not stop talking about it but there should be a comfortable middle ground.

Jeep is also guilty of being weary of going into detail about their transfer cases. They haven’t helped themselves with their naming conventions that overlap, swap or reappear with a different function from generation to generation. At least Ford is consistent in that department.

They probably all have decided to focus on electrified platforms and having to come up with sales pitches for all their shiny new tech.

The key word seems to be ‘Preemptive’ rather than the original system’s reactive response. This is most likely thanks to dramatically improved sensor inputs, processor speed and programming memory versus the limitations on technology of a quarter century ago.
 

imnuts

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The fact that this information is buried in the workshop manual shows Ford’s disinterest in the system.

Someone shopping for a vehicle shouldn’t have to be burdened with taking such a deep dive to find the answer for such a simple question. I’m not saying that they should be like Subaru and never not stop talking about it but there should be a comfortable middle ground.
Manufacturers don't go into detail because 99%+ buyers simply don't care. I've overheard conversations already of people that bought/leased vehicles and didn't realize how something worked until after they signed the paperwork. I'm sure there are a vast number of drivers that couldn't even tell you if their car is FWD, RWD, AWD, or 4WD. If they did know, and it was an AWD vehicle, they probably have no idea how the AWD system works or what the limitations are.
 

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Snakebitten

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Manufacturers don't go into detail because 99%+ buyers simply don't care. I've overheard conversations already of people that bought/leased vehicles and didn't realize how something worked until after they signed the paperwork. I'm sure there are a vast number of drivers that couldn't even tell you if their car is FWD, RWD, AWD, or 4WD. If they did know, and it was an AWD vehicle, they probably have no idea how the AWD system works or what the limitations are.
In no way do I mean this as disparaging of anyone, but here on this very forum there are considerable numbers of consumers that have purchased a Gen14 F150 and are completely unaware of the many features and options of the truck.
Consider the percentage that will never "lock out" a gear ratio or two? Or even know the button is there for you to.
There's been a few that didn't know they could switch Driver Select Mode.

So yea, it's not likely that most are curious about the various transfer cases that Borg Warner makes available to the Ford F150 assembly line.
 

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Someone shopping for a vehicle shouldn’t have to be burdened with taking such a deep dive to find the answer for such a simple question. I’m not saying that they should be like Subaru and never not stop talking about it but there should be a comfortable middle ground.
Fair enuf (y)

I agree that Ford's consumer sales literature and retail website are lacking when it comes to meaningful, even if simplified, explanation of the differences between the two available 4WD systems (ESOF / TOD with 4A).

And yeah, even the somewhat more illuminating info in the owner's manual (which requires conscious effort to download as a PDF, the touted ability to read it on the 12" dashboard display being a cruel joke) is difficult to glean from among the many sections addressing those systems.
 

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...it's not likely that most are curious about the various transfer cases that Borg Warner makes available to the Ford F150 assembly line.
It’s one thing spoon feeding minutiae about a system and not even mentioning it entirely on the build and price configurator.

Ford F-150 How 4A mode works? F86D8E18-65F6-4F20-A9D1-1DB58C6935F1


Ford F-150 How 4A mode works? 43166DE4-5DDE-4E4C-85F9-19AF6FD8E93A



I’m pretty pessimistic and skeptical when it comes to most things but I would like to think that at least one out of twelve potential buyers would be able to comprehend a one paragraph summary describing the 4A and it would potentially have more weight when selecting trims and packages.

The crazy thing about the configurator is you can see if it has 4A or not by viewing the 360° interior view and looking at the drive mode selector buttons.

Ford F-150 How 4A mode works? C6ADFF41-B2D9-47A4-9A94-582A5FA457E3


Jeep will even let you filter models on their online configuration tool by the transfer case.

I don’t think Jeep buyers are any more or less savvy than Ford buyers and there will always be clueless people, they just tend to stand out more because they attract more attention; just take a thirty minute drive on the highway in any big American city.

Borg Warner doesn’t just let Ford buy the TOD transfer case, it was an exhaustive years long cooperative development that allowed Ford exclusive use of the technology for a period of time.

https://www.theautochannel.com/news/press/date/19971222/press008795.html

Advertising works and the higher ups at Ford decided that 4A is old news. If they decided to inform their buyers, more people who would otherwise be clueless would at least be aware of its existence. There’s plenty of people that have ordered Captain and Cokes without realising it’s just a rum & coke but it doesn’t mean that they didn’t enjoy it any more or less.

They do mention it in the press release for the next gen. rest of the world Ranger. Hopefully it will be an option in North America.

Ford F-150 How 4A mode works? F3761310-E7D5-4BD1-AC94-4C07478B0336


There are some people that just can’t really be helped when it comes to operating a vehicle after a certain point and the irony of that is 4A is their best option.

Ford F-150 How 4A mode works? 4F1DE248-B6A1-4F7A-B14B-D7CD8D2EE15A


When selecting an off-road vehicle for a family member, the only choice was full-time or AWD 4X4 system. The 4Runner Limited was the perfect choice for them and Toyota has the info front and center when looking at the various options online.

And yeah, even the somewhat more illuminating info in the owner's manual (which requires conscious effort to download as a PDF, the touted ability to read it on the 12" dashboard display being a cruel joke) is difficult to glean from among the many sections addressing those systems.
Don’t get me started with the bullshit digital owners manual. It took me thirty minutes to find the headlight fuse because I had to update Fordpass. How much would it have cost them to label the fuses on the fuse cover? I’ve been meaning to print and laminate some index cards for the fuse boxes.
 

Jimi

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FWIW, following in italics is a verbatim excerpt clipped from the the Ford Workshop Manual (TCCM = Transfer Case Control Module):
_____________________________________

307-07A Four-Wheel Drive Systems
2022 F-150
Description and Operation Procedure
revision date: 03/24/2022

Four-Wheel Drive Systems - Vehicles With: 2-Speed Torque On Demand Transfer Case - System Operation and Component Description
......

In 4WD AUTO (4A), the TCCM continuously monitors conditions and driver input to send torque automatically to the front driveline by controlling the transfer case clutch, providing 4WD capability. The TCCM sends a duty cycle command to the transfer case clutch coil as a torque request based on combination of preemptive and wheel slip response algorithm. Preemptive response is based on steering wheel angle, vehicle speed, throttle positions and available powertrain torque. Wheel slip response is based on monitoring the average front and rear wheel speeds.

When 4WD is no longer needed (during cruising or steady state driving) system defaults back to RWD (rear wheel drive) mode by setting the duty cycle output to 0.

TCCM increases the duty cycle to prevent or control slip under any of the following conditions:

  • Slip is detected.
  • Heavy acceleration (throttle position).
  • Straight-ahead steering wheel angle.
TCCM decreases the duty cycle to prevent or reduce vehicle bind under any of the following conditions:
  • Low speed.
  • Low acceleration (throttle position).
  • Tight turn steering wheel angle.
The TCCM has a thermal hardware protection strategy which monitors the amount of energy going through the clutch. This strategy has 2 levels of protections:

AUTOLOCK: If the system is in 4WD 4H
[***] and TCCM detects driving conditions that require greater 4WD performance, the TCCM temporarily turns on 4WD (4H) from 4WD AUTO (4A) after detecting driving condition and informs the customer via the message center indicating 4X4 TEMPORARILY LOCKED. The 4WD system automatically returns to 4WD AUTO (4A) after the system no longer detects these driving conditions and informs the customer via the message center indicating 4X4 RESTORED.

POWERTRAIN TORQUE PROTECTION: If the system is in 4WD AUTO (4A) and TCCM detects excessive stress or high energy going through the clutch (clutch is slipping excessively while the system is commanding max clutch torque), clutch output will be turned off and message center indicates 4x4 TEMPORARILY DISABLED. When the system had the ability to cool off, 4x4 operation will be automatically restored.

NOTE: The 4x4 Temporarily Disabled message can be dismissed by the customer however it's advisable to let the TCCM clear the message itself, which indicates that the 4x4 system has resumed normal operation.
.....

_______________________________

[***] NOTE - I believe that the term "4WD 4H" used here is a typo in the WSM text and should be "4WD 4A".

I suggest that the pictorial power distribution display simply isn't programmed with the sophistication required to reflect the sophistication of the actual moment-to-moment driveline behavior / status when in 4A mode. Yeah, that's a bit cheesy (and maybe a bit lazy on Ford's part, it would seem that the duty cycle commands from the TCCM could be used for the purpose of altering that display image to reflect what's really going on) but that display has nothing to do with the actual functioning of the system. On the other hand that might be intentional to prevent folks from freaking out when they see how little time is actually spent with power directed to the front wheels when in 4A mode (;)).
Thanks Buyer 2021. I'm learning a lot about my 2023, that I haven't received yet. I appreciate you guys. 👍
 

Pedaldude

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Thanks Buyer 2021. I'm learning a lot about my 2023, that I haven't received yet. I appreciate you guys. 👍
If only Ford were as good at educating their customers! I’m actually going to have to say they’re more than blasé and that they’re downright apathetic about the torque on demand transfer case.


...this 2022 doesn't have IWE's so it seems to show less difference in fuel economy between 2Hi and 4A. Driven as closely the same as possible, on a daily commute that hasn't changed in 22 years, I get a variance of less than 1mpg.

I do get a drop in mpg in heavy rain, but I suspect that is rolling resistance? It can cost as much as 1mpg on the same 46 mile round trip.

...my 2022 Powerboost dropped its EPA rating of 24mpg (2021 Powerboost) to 23mpg. I can vouch that there literally is about a 1mpg difference. Is it the IWE removal? (or at least some portion of the 1 mpg is the IWE removal?)
The lack of IWE in 2H absolutely impacts MPG; otherwise, they wouldn’t really need to exist. Same thing with Jeep’s front axle disconnect and Toyota’s automatic differential disconnect.

Ford probably knows exactly how much energy it takes to idle the front differential and half shafts and then calculated that they could get in under the CAFE numbers thanks to the PB and Lightning.

While the rotating assembly of the axles is likely significant, the differential gears constantly churning thick gear oil is a huge portion of that 1mpg difference.

Your experience echoes that of the people who swapped out the three position switch of the 1st gen. Navigators that lacks 2H with the four position Expedition switch and saw no noticeable change of mileage in 2H.

Rain, wet roads and snow have a measurable effect on rolling resistance and critical to that is correct tire pressure. I never would have guessed it but higher pressure tires are better in the rain to ensure adhesion to the road surface and it increases with speed, which is one of the reasons why airplane tires run silly high tire pressures.

Ford F-150 How 4A mode works? D514DCCC-D4CB-4AE6-BC40-BA86A9D61C14


Here’s a graph of the effect of snow on rolling resistance, with newtons as the measurement of force and millimeters for depth of snow.

Note that the depth in mm increases by 50mm for every line on the graph, while N goes up by 200.
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