Kill-switch for electronic nannies

[Retired BLM Rig]

Even though we have a manual t-case, there is still a t-case position sensor. Is the TCPS ONLY for our lockers or would it also prevent 4wd if a WSS got snagged as you say ? I am curious.

The TCPS doesn't control anything, it only provides information to modules. It informs the BCM so it can illuminate the appropriate instrument cluster display message (4X4, 4X4 Low). The ECM changes throttle response. The TCM changes shift points in low range. The FDCM allows locker function in low range. I'm not sure which module locks the CAD.

On a 3rd or 4th gen, for the 4X4 system to quit working you would have to have a hard part failure (linkage, gears, chain, shafts, U-joints). If all that is good you actually have a 4X3, thanks to the LS rear axle. If all of the electronics are working properly, you can engage the lockers and have a true 4X4. You could rip out all the wheel speed sensors and still have a 4X4.

On the 4.5 gen with the CAD front axle that's electronically controlled, it's anybodies guess. Stay tuned.

For my money, I would rather have a solid front axle with old school locking hubs (free spin kit).

[olyelr]

Got a little snow coverage today. So I pulled the wheel speed sensor connector like BLM suggested, started the truck with one push of the button, watched a few lights come on the dash, and headed out and proceeded to do donuts around the cul de sac like any seasoned teenager would do. Drop her in four by four mode... light just blinks (actually, also a weird type of sound from down by the transfer case was also heard... almost like a grinding, but a very laid back grinding... then it went away). Back in 2 wheel and back to 4 wheel several more times with the same outcome. Drop her in 4 low, the case goes in low but front axle still does not lock in. Well shit. Must not be allowing the CAD to engage?

[Low_Sky]

Yeah, sounds like it. If you go in and out of 4wd (with everything plugged in and working) with the window rolled down, you can hear the CAD servo/solenoid/? moving. The low grinding you heard was probably that.

[TwinStick]

Where do they find the people that make these decisions ?

So, it is supposed to be "the premier off road truck", yet it can simply leave you stranded in the middle of no where, if brush snags a wheel speed sensor ??? They REALLY need to re-evaluate the need to keep those people employed. I mean REALLY, is there anybody here that thinks that is a good idea ?

[olyelr]

Where do they find the people that make these decisions ?

So, it is supposed to be "the premier off road truck", yet it can simply leave you stranded in the middle of no where, if brush snags a wheel speed sensor ??? They REALLY need to re-evaluate the need to keep those people employed. I mean REALLY, is there anybody here that thinks that is a good idea ?

In here? Well FAWK NO

I agree. That is freakin' stupid. Makes no sense. Cant imagine why they designed it like that.

Well, at least when the ABS fuse is pulled the front axle still locks up. Looks like that is still the method we will have to take.

Thanks for the idea though BLM, keep 'em coming!

[olyelr]

On a upside to all of this, if there is such a thing, is putting a switch on this would be a cheap way to make your own 2-low kit.

[NickTF]

The sheer fact that all of these nannies can't be turned off is amazingly stupid. But one need only look to the post state of the union replies tonight to understand how things like a truck designed to operate in mud and challenging slippery offroad surfaces pulls throttle during loss of traction came to be designed. Easy enough to pull the fuse and get that stupidity out of your life when conditions call for it, or as i've been doing just learn to not have cruise control.

[Mule]

Where do they find the people that make these decisions ?

Engineering schools.

I've worked with engineers who are great engineers but have no concept of the machines they design in reality.
I know several engineers who need to have their toolboxes welded shut. Smart people, brilliant on paper/design, just not hands-on at all.
And I also know a lot of technicians who should be helping out engineering teams more than they do.

Feel like most automakers hire new grads with little real-world experience... which leads to decisions like that.

[olyelr]

The sheer fact that all of these nannies can't be turned off is amazingly stupid. But one need only look to the post state of the union replies tonight to understand how things like a truck designed to operate in mud and challenging slippery offroad surfaces pulls throttle during loss of traction came to be designed. Easy enough to pull the fuse and get that stupidity out of your life when conditions call for it, or as i've been doing just learn to not have cruise control.

I understand why the truck has so many nannies. It is inevitable these days, no way around it... its just hard to understand why the engineers designed it so the 4wd no longer works if it doesnt sense wheel speed from one of the tires (or whatever the hell sensor thingy is causing the CAD to not engage).

Honestly, I like the nannie systems in place for most normal day to day driving (could certainly do without ABS, though). That is why I dont like to pull the fuse and leave it out. But, when I am in off road mode EF all that stuff. And I want a damn switch to do it LOL.

[olyelr]

Where do they find the people that make these decisions ?

Engineering schools.

I've worked with engineers who are great engineers but have no concept of the machines they design in reality.
I know several engineers who need to have their toolboxes welded shut. Smart people, brilliant on paper/design, just not hands-on at all.
And I also know a lot of technicians who should be helping out engineering teams more than they do.

Feel like most automakers hire new grads with little real-world experience... which leads to decisions like that.

I totally agree. Engineers have their place, no doubt. But a little more conglomeration between them AND users/technicians/real world people would certainly help in almost all situations.

Almost like an architect in a builders world hahaha.

[TwinStick]

Yup, you would certainly think that some real world input from the end users would be beneficial to everyone. End users, engineers and most importantly (from their point of view anyways) the Manufacturer because they would sell more & make more money, which is all they seem to care about.

Bouncing ideas off everyone involved------now there is a novel idea !!! Had they been doing that all along, we may not be in the nannie state that we are now in.

It would certainly be simple enough for them to do. When 4Hi is engaged, it should eliminate everything except ABS. When 4Lo is engaged, it should eliminate everything-including ABS. Make the owner sign something acknowledging all that & bamm, done. I mean, the winch can kill you & you don't have to sign anything for that.

[NickTF]

Sure there is a way around it, give me a damn button to press to rid myself of 100% of these foolish nannies. The sequence can even be made involved so the normal dope that hurts himself easily is unlikely to access the 100% off
Option.. It’s not complicated, give me the choice. Anything which does not is pure stupidity or short sighted. As one poster indicated the winch cable is likely far more dangerous than half assed throttle control restriction. I mean the Demon requires signing some form of release if that’s what it takes for common sense show me where to sign. Justifying stupidity is why we get more of it every day. Love my truck but having to pull a fuse, while extremely easy, is super stupid for a truck of this Nature period.

[Retired BLM Rig]

Got a little snow coverage today. So I pulled the wheel speed sensor connector like BLM suggested, started the truck with one push of the button, watched a few lights come on the dash, and headed out and proceeded to do donuts around the cul de sac like any seasoned teenager would do. Drop her in four by four mode... light just blinks (actually, also a weird type of sound from down by the transfer case was also heard... almost like a grinding, but a very laid back grinding... then it went away). Back in 2 wheel and back to 4 wheel several more times with the same outcome. Drop her in 4 low, the case goes in low but front axle still does not lock in. Well shit. Must not be allowing the CAD to engage?

Does it behave the same way if you unplug a rear ABS/WSS?
Maybe if the computer knew that both wheels on the CAD axle were at 0 MPH, perhaps it would allow engagement. It might be worth a try... or a complete waste of time.

[olyelr]

Does it behave the same way if you unplug a rear ABS/WSS?
Maybe if the computer knew that both wheels on the CAD axle were at 0 MPH, perhaps it would allow engagement. It might be worth a try... or a complete waste of time.

Hmm, good thought. I do know it would not lock up even when the truck was not moving. I sat there idle for a while watching the light blink. But maybe unplugging both would change something? Most likely will be a waste of time checking, but it wont be much time I might be able to get to it later today.

[olyelr]

Ok. Disconnected both wheel speed sensors up front and it still does not allow the CAD to engage.

I did not try the backs at all. There is no way in hell i would attempt to disconnect them given the location is extremely difficult to get to. Hell, I dang near broke both of the front clips and I was staring right at them.

[NickTF]

Did you try disconnecting the wheel speed sensor opposite the first sensor you tried while leaving the first sensor you tried plugged in? Grasping at straws here but maybe it makes a difference.

[olyelr]

Did you try disconnecting the wheel speed sensor opposite the first sensor you tried while leaving the first sensor you tried plugged in? Grasping at straws here but maybe it makes a difference.

Ha, no I didnt. Will give it a whirl later today.

[NickTF]

Did you try disconnecting the wheel speed sensor opposite the first sensor you tried while leaving the first sensor you tried plugged in? Grasping at straws here but maybe it makes a difference.

Ha, no I didnt. Will give it a whirl later today.

Thanks for trying this. I'm hoping that the two wheels aren't treated the same logically in the computer given the driver side is always engaged to the differential while the passenger side doesn't engage until the CAD collar slides over and locks the intermediate and passenger side shafts together. Ofcourse, thinking logically about how the systems are implemented in this truck is probably an exercise in foolishness.

[olyelr]

Ok, I tried it with just the sensor on the passenger side. It still dosnt work.

Oddly enough, though, I did find out that if I swing it into 4wd before the “check anti-lock braking system” light comes on right when the truck is started, the CAD will lock up. But if the light is on, then it wont lock up

But when that light is on from pulling the fuse, It will lock and unlock to your hearts content.

[Colibri]

One piece inner axle shaft solves all your problems

[NickTF]

Well all possibilities were covered with the speed sensors in the front atleast.

Well atleast us CAD guys can make the double cardan joint live longer with no greasing.... *searches for optimism

[olyelr]

One piece inner axle shaft solves all your problems

Well, while that and a set of lockouts would be handy and are available, it still doesnt prevent the nannies from kicking in.

Still need a switch on something!

[Colibri]

Absolutely, it would only give you 4wd when the computer would otherwise prevent it.

I don’t envy you guys with the newer wagons when it comes to nannies. What a headache.

[Retired BLM Rig]

Ok, I tried it with just the sensor on the passenger side. It still dosnt work.

Oddly enough, though, I did find out that if I swing it into 4wd before the “check anti-lock braking system” light comes on right when the truck is started, the CAD will lock up. But if the light is on, then it wont lock up

But when that light is on from pulling the fuse, It will lock and unlock to your hearts content.

So, if it was on a toggle switch, you could flip the switch and do donuts in 2WD, or if you wanted no nannies off roading in 4WD, couldn't you engage the T-case first to lock the CAD and then flip the switch to disable nannies. And what about lockers and swaybar, will they work with the ABS light on? Back to the lab for more testing Beaker.

[Reloaderguy]

I don’t envy you guys with the newer wagons when it comes to nannies. What a headache.

Umm, you can just pull the ABS fuse.