Anyone drive in 4A and seems to hunt for traction

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smurfslayer

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I mostly tool around in 4a because the street traction on the KO2’s is below average and the truck has a $hit ton of torque available and it’s a pickup truck so it’s easy to break the tires loose even with the nannies. AWD has a different feel than fwd or rwd period.
All the time? Even in normal non-slippery dry conditions?

Something isn’t right here. According to the manual, the 4A mode provides power to the 4WD system, as required. Mine is putting power to the front all the time... even in dry conditions. If 4A is designed to be in 4WD all the time, then why have the 4A at all?

so what kind of driving? Are you former hypermiling prius driver? Blue haired, 10 under the limit driving by brail senior? Ex minivan soccer mom pilot? nervous nellie dude? grocery getter / street queen / use Rap as a posing vehicle? Just daily driving it? Some performance car history? Sport biker/auto-x/open track hero? off-roaded all your life and this truck is just a canvas you use to transform into what you need?

or something in between - just looking for context here.

because if you’re driving hard and caning the truck like it was meant to be, you’re going to get more nanny intervention but before nannies, the 4a system is going to try to assist also. It’s not bullet proof, you can still get sideways in 4a with all the nannies, even in normal mode. The colder the pavement, the less tire temp, the less potential traction you have with cold tires and even when they warm they’re not anywhere close to where they are in the summer. And once the first snow hits and the states start dumping sand, salt and whatever else they’re using, road debris from that lasts through the first downpour - at least.

Isn’t the 4WD system controlled by an air valve system... I think I read there’s a vacuum controlled valve that commonly gets stuck?

you did, and it can get stuck trying to engage, typically manifesting by a clicking sound. I believe the system applies vacuum to achieve 2wd, and if it loses vacuum the system fails back to locked hubs.
 

JohnC12

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I mostly tool around in 4a because the street traction on the KO2’s is below average and the truck has a $hit ton of torque available and it’s a pickup truck so it’s easy to break the tires loose even with the nannies. AWD has a different feel than fwd or rwd period.


so what kind of driving? Are you former hypermiling prius driver? Blue haired, 10 under the limit driving by brail senior? Ex minivan soccer mom pilot? nervous nellie dude? grocery getter / street queen / use Rap as a posing vehicle? Just daily driving it? Some performance car history? Sport biker/auto-x/open track hero? off-roaded all your life and this truck is just a canvas you use to transform into what you need?

or something in between - just looking for context here.

because if you’re driving hard and caning the truck like it was meant to be, you’re going to get more nanny intervention but before nannies, the 4a system is going to try to assist also. It’s not bullet proof, you can still get sideways in 4a with all the nannies, even in normal mode. The colder the pavement, the less tire temp, the less potential traction you have with cold tires and even when they warm they’re not anywhere close to where they are in the summer. And once the first snow hits and the states start dumping sand, salt and whatever else they’re using, road debris from that lasts through the first downpour - at least.



you did, and it can get stuck trying to engage, typically manifesting by a clicking sound. I believe the system applies vacuum to achieve 2wd, and if it loses vacuum the system fails back to locked hubs.

Thanks for the info, Smurf.

I came from a 2017 F150 Lariat. Before that a 2015 Chevy Tahoe. Before that a 2010 Ford Explorer. Never, and I mean never have I owned a Prius... and never will.

As for my Raptor, she's a pavement queen, but I drive her hard on the pavement.

I've tested the 4A in all kinds of conditions, including dry pavement. And as others have posted above, no matter what, she sits in 4WD the entire time. On side note, I too am driving a 2019 with 12k.
 

smurfslayer

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This one hits home, because yes.

I'm pretty much a granny when I drive. I don't really trust drivers around me otherwise things would be different.

Then my opinion is it’s probably your expectation is different from what the truck delivers. You can get similar “different” driving feel from a Subaru or similar full time awd as a comparison.

As for my Raptor, she's a pavement queen, but I drive her hard on the pavement.

I've tested the 4A in all kinds of conditions, including dry pavement. And as others have posted above, no matter what, she sits in 4WD the entire time. On side note, I too am driving a 2019 with 12k.

Lucille is a late ’16 build ’17 MY, and when we’re in 4A, the front hubs are locked, with drive power being applied “as needed”. I believe this is unchanged through the model years. I think that the power distribution screen may be misleading us a little, and I suspect the system is working as designed.
 

Donmatteo

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Lucille is a late ’16 build ’17 MY, and when we’re in 4A, the front hubs are locked, with drive power being applied “as needed”. I believe this is unchanged through the model years. I think that the power distribution screen may be misleading us a little, and I suspect the system is working as designed.

Im going to respectfully disagree

my MY18, build 18 802a with the diff applied power as needed. As shown on the power distro screen and by the feel of the truck.

my MY19, build 19 802a with the differ applies all the time as shown on the power distro screen and by the feel of the truck

Now either there was a change to the system with the addition of the trail cruise or they changed something else.
 

lka

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We have snow right now...

Friday I drove the 18 to the dealership using 4a off the mountain, I drove the 20 back to the mountain and needed 4a. They feel the same to me.
 

smurfslayer

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my MY19, build 19 802a with the differ applies all the time as shown on the power distro screen and by the feel of the truck

so you’re saying that the ‘demand’ strategy is different, that it’s actually applying a minimum / variable amount of power to the front wheels 100% of the time, correct?

That’s different than what we all know and understand but who knows - anything’s possible. I’m not sure how you could validate or invalidate this.
 

Donmatteo

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so you’re saying that the ‘demand’ strategy is different, that it’s actually applying a minimum / variable amount of power to the front wheels 100% of the time, correct?

That’s different than what we all know and understand but who knows - anything’s possible. I’m not sure how you could validate or invalidate this.

Yes. With my 18, in slippery, 4a, it would alternate between 2h and 4 and vary traction based on throttle.

With the 19, in slippery, 4a, it is always in 4 and varies traction based on throttle but never swaps to 2.

I’ve owned several 4a cars over the years and I can assure you I know how 4a works.

I am simply pointing out there is a difference between the 18 and 19 and how 4a seems to be working.
 
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