Brake as in applying the brakes, nope.
Braking as in engine braking, yes.

The real question is what does the DSC system do?

The FDI front and rear are not "limited slip" which means that if the wheel is spinning on one side, the other side will just sit there. In 4X4 mode, the power is distributed evenly between the front and rear but not side to side. In AWD mode, power is diverted from the front to the rear as needed.

I would be a bit concerned with twisting the chassis on an FDI Patriot as it does not have the chassis re-enforcement in the rear that the FDII does....

 

I would be a bit concerned with twisting the chassis on an FDI Patriot as it does not have the chassis re-enforcement in the rear that the FDII does....

huh??? I don't see "chassis reinforcement on the list.



Freedom-Drive II Off-Road Group $ 975

140 Amp Alternator
Tire & Wheel Group
Tires: P215/65R17 OWL All Terrain
4-Wheel Drive Off-Road Mode
Air Filtering
Brake Lock Differential
Engine Oil Cooler
Fog Lamps
Fuel Tank Skid Plate Shield
Hill Descent Control
Passenger Assist Handles
Tow Hooks
Trail Rated Badge
Transmission/Engine Oil Pan Skid Plate

 

I believe that they did mention a reinforcement of some sort.

As for traction control, all Patriots come standard with it as part of the ESP program. It is not the same as Brake Lock Differentials that is unique to the FDII models.

 

so what does a FDI do when two wheels are in the air?

 

The electronic stability control will provide some braking to assist with traction when a wheel is in the air.

 

I hope that this is large enough to read.

 

Actually all Patriots have additional frame support... As you see in this photo it has a normal looking truck frame added to the standard Unibody design.

This was a selling point for the 2007, not the 2008 so much from what I have seen.

*disregard the red circle. I used the same photo to show low points in clearance in another thread.

 

Pretty funny gramps and I were posting the at the same time... but in both our photos you can see they do not mention additional frame, cross rails or anything... but you can also see they have more of a frame than most unibody's too.

 

Jim, what a hoot! (that's a mid-west expression the best that I can figure out). I thought that I had read somewhere (in the early info) that it had more reinforcements too. Other than what Jim has pointed out there are the 3 bars welded on to each of the rear lower control arms on the FD II that are not on the others, easy to add on if you have access to a welder.

 

the only thing that i know of that has additional reinforcement are the rear lower control arms which appears to me to be more of an additional 'skid plate' for the rear suspension, not so much 'additional reinforcement'.

i would still have to see a 'std' Patriot and a 'Trail Rated' Patriot from the view above to see if there are any additional crossmembers. as far as i know, there's nothing additional on the 'frame' or uni-body. :doh:

 

This is in my Compass owner's manual, which is not even availible with FDII. I don't expect Patriot FDI to be any different. In fact, it can never be disabled, brake TC as a form of electronic limited slip differential.

Traction Control System (TCS)
This system monitors the amount of wheel spin of each of the driven wheels. If wheel spin is detected, brake pressure is applied to the slipping wheel(s) and engine power is reduced to provide enhanced acceleration and stability. A feature of the TCS system functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning. This feature remains active even if TCS and ESP are in
either the “Partial Off” or “ESP Off” modes. Refer to “Electronic Stability Program (ESP)” in this Section of this manual.

 

APT, I too have posted that paragraph in another conversation regarding this matter. Which is why I truly believe the only differences is the lower gearing (which isn't really that much lower anyway) in the FDII than the FDI, oh and the additional clearance.

 

So you believe that Brake Lock Differentials are the same as Traction Control? Do you also believe that the off-road anti-lock brakes, tow hooks, skid plates, heavy duty cooling, fog lamps, and extra water sealing are imaginary?

ESP and Traction Control are discussed as something standard on all Patriot models at the following link: http://www.jeep.com/en/2008/patriot/safety_security/accident_avoidance/

Note that it is under the Safety and Security heading, in the Accident Avoidance subheading. Click on "Electronic Stability Program [1] and read the description.

Brake Lock Differentials is discussed as a unique feature for FDII models. Here is the link: http://www.jeep.com/en/2008/patriot/capability/drive_systems/

Note that it is under the Capability heading, in the Drive System subheading. Click on Freedom-Drive II 4WD Off-Road Group and read the description.

They are not the same, although they may have similar jobs. We can agree that low gearing in the FDII is not the same as the "L" on the Compass and FDI. They would be used for similar instances, but the FDII is more aggressive.

Why can't the same be said for Brake Lock Differentials? Perhaps it is a more aggressive version of TC that reacts more quickly and harshly to wheel-slip and doesn't cut throttle.

Maybe the Brake Lock Differentials would be too harsh for everyday driving...like when you require some differences in wheel spin. Turning is a great example...thus it isn't good for a vehicle like the Wrangler to have Locking Differentials always engaged. Perhaps the BLD's would interfere with steering in a similar way to the Wrangler's mechanical Locking Differentials.

Hence, Traction Control is used for everyday driving. But TC wouldn't cut it for off-roading, so they developed BLD's.

How is this hard to accept?

 

ok you got me on a few of them unclejjg... however noonne has proven the extra water sealing around the doors... I know I compared the ones at my dealer and my offroad FDI looked the same as the FDII they had.

The gearing is more aggressive (or lower) 19:1 rather than 15:1...

Ok that does make sense to me unclejjg... I wonder how long it be before we can see a product that adds on traction lock control for non-FDII.

 

If the aftermarket (ARB or Eaton) would step up and make an air or electric controlled mechanical locker for the MK's, we could clear this whole thing up in a jiffy!

 

I don't expect that to happen (aftermarket axle control). You would need to unplug the ESP (whcih is probably also ABS) module as it would intefere.

 

Do you think so? I don't know. If it was selectable, I don't think it would be a problem. In fact, I have to strongly disagree due to the fact that the Rubicon Wrangler (front and rear locker) also comes standard with the ESP.

I think the limiting factor here would be whether or not the MK's are beefy enough to withstand the extra strain a true selectable locker would put on things.

 

I am sure with the SRT out now a front locker will soon be available...

 

There is a difference between offering something from the factory and aftermarket. OEM can provide the interfaces to disable TC when the axles are locked. Aftermarket is more difficult, if not impossible. I agree it is possible, but the system has to be designed and integrated accordingly. If the OEM components are not designed for those interfaces, that makes it impossible.

BTW, I work for an ABS/TC/ESC supplier. Not the one for the MK's (too bad), but we do have products for off-road type vehicles, HDC, hill assist, etc. While by no means an expert, I do have some knowlege about the capabilities/limits of the systems used in MK's.

 

There is a difference between offering something from the factory and aftermarket. OEM can provide the interfaces to disable TC when the axles are locked. Aftermarket is more difficult, if not impossible. I agree it is possible, but the system has to be designed and integrated accordingly. If the OEM components are not designed for those interfaces, that makes it impossible.

How do you account for companies like ARB or Eaton making locking differentials for Wrangler Saharas and X's or the '07 Liberty that have ESP?

I've always wondered if it is a situation where when the selectable aftermarket locker is engaged, there is no slippage for the OEM electronic system to detect...so it just doesn't try to do the job it normally would. It seems like there would be no interference at all.

 

BLD shoud not activate when all 4 wheels are on the ground (i.e. everyday driving).

Says who? That would be a lousy system. What if one wheel is in mud/snow/ice, while the other wheel is on dry land. The BLD's won't operate because there isn't a wheel in the air?

Again, I believe the determining factor here is wheel slippage. I suspect BLD reacts faster and more aggressively than TC. This could be detrimental in everyday driving, which may explain why TC is the standard, and BLD is the added feature.

Actually from what I understand it depends on how fast the vehicle is moving and whether or not its in 4 wheel drive... not if the wheel is touching the ground or in the air. But even then the TCS would still stop the one from spinning by definition. I think they are playing with words and alot of people are buying into it...

As for a test or comparison. It would be extremely hard because one driver may be more experienced and/or the lines maybe different thus creating different results.

 

As for a test or comparison. It would be extremely hard because one driver may be more experienced and/or the lines maybe different thus creating different results.

use the same driver. Let me borrow your jeep!

 

Here's an informative blog on BLD. It doesn't go into specifics about the ESC, but eludes that there are differences. In fact, it goes so far as to say the BLD will go most places that a true locker can go. I don't the basic ESC as being that good, even if it is just a program change.
http://blog.chryslerllc.com/blog.do?id=270&p=entry

EDIT: It is not patriot specific, and in fact doesn't even mention the patriot.
I just noticed a comment at the bottom concerning the Compass, included for your pleasure:

“I don't Off Road, but I'm now curious if my FWD Compass uses BLD for traction control? I've been a little disappointed in my Jeep's traction control, but I feather the throttle when I encounter wheel spin. From your article, it sounds like I need to cautiously add throttle. Is this correct?”


Yes, your FWD Compass has BLD as part of the traction control system. The difference is that BLD works a little different in 4wd low range. When a Jeep of Dodge vehicle equipped with ESP and a two speed transfer case is shifted into 4wd low range, the BLD is more aggressive at controlling wheel spin side to side across an axle. This is desirable off road but not on road. There are two answers to your question depending on the circumstances of the wheel spin. If you are moving in the desired direction and the wheels start to spin, feathering the throttle is the correct action. If the vehicle is not moving and one wheel is spinning and the other is not, sometimes cautiously adding a little throttle may help for the reasons stated in the article.

 

Soon heckler and I'll get out and get a FDII vs 5sp FDI done. I should have mine before the end of the month.

 

Sweet! Make sure you get a hitch so I can pull you out.

 

Here's an informative blog on BLD. It doesn't go into specifics about the ESC, but eludes that there are differences. In fact, it goes so far as to say the BLD will go most places that a true locker can go. I don't the basic ESC as being that good, even if it is just a program change.
http://blog.chryslerllc.com/blog.do?id=270&p=entry

EDIT: It is not patriot specific, and in fact doesn't even mention the patriot.
I just noticed a comment at the bottom concerning the Compass, included for your pleasure:
Quote:
“I don't Off Road, but I'm now curious if my FWD Compass uses BLD for traction control? I've been a little disappointed in my Jeep's traction control, but I feather the throttle when I encounter wheel spin. From your article, it sounds like I need to cautiously add throttle. Is this correct?”


Yes, your FWD Compass has BLD as part of the traction control system. The difference is that BLD works a little different in 4wd low range. When a Jeep of Dodge vehicle equipped with ESP and a two speed transfer case is shifted into 4wd low range, the BLD is more aggressive at controlling wheel spin side to side across an axle. This is desirable off road but not on road. There are two answers to your question depending on the circumstances of the wheel spin. If you are moving in the desired direction and the wheels start to spin, feathering the throttle is the correct action. If the vehicle is not moving and one wheel is spinning and the other is not, sometimes cautiously adding a little throttle may help for the reasons stated in the article.

Doesn't get any better than this explanation. Pretty clear and it comes from someone in the know. The article is great and needs to be read to fully understand the writer's answer to the above question. The difference is in the cross-axle braking which is available to the FDII Patriot in 4WD Low.

 

Now that it was posted by Chrysler on Chrysler's own blog if its not true its false advertising...

However the blog writer (Loren Trotter) said "Yes, your FWD Compass has BLD as part of the traction control system." flat out. She then states that the 4wd models are more aggressive when it comes to stopping wheel spin if it has a transfer case and is in low lock... But guess what neither the Compass nor the Patriot (FDI and FDII) have transfer cases!

So to me this means all MK's have BLD's regardless of FDI or FDII. Now I may be wrong but to me it also means that since MK's do not have transfer cases neither has the more aggressive BLD's that the Wranglers, Grand Cherokees and Commanders have. Which can be cross referenced with her first post where she states "Since then, traction control has been added to the Commander, Liberty and Wrangler." This really surprises me that that Liberty was not included with this feature as the time she wrote that (on Feb. 11th, 2008) because it does have a transfer case with low lock.

 

http://blog.chryslerllc.com/blog.do?id=270&p=entry

" there is a feature of brake traction control that controls wheel speed side to side across a driven axle and is called BLD, or "brake lock differential.

Using the vehicle’s wheel speed sensors, BLD knows when one wheel on a driven axle is turning and the other is not. BLD will apply brake pressure to the wheel that is turning.

The applied brake pressure increases the torque required to turn the wheel in the air and this allows more torque to go to the wheel on the ground."


...sure sounds like ...

"A feature of the TCS system functions similar to a limited slip differential and controls the wheel spin across a driven axle. If one wheel on a driven axle is spinning faster than the other, the system will apply the brake of the spinning wheel. This will allow more engine torque to be applied to the wheel that is not spinning."

I'm sure it is at a minimum more agressive form, but BLD is the same principal as the standard ESP (2WD or FDI).

 

Good info. I am still wondering about the additional chassis re-enforcement that I found in the parts catalog. It did not show how it was attached so perhaps it really is the re-enforcement for the arms. The images are rather vague....

 

Another valid point is that a few magazines and internet sites are saying even the 2wd Wrangler has BLD's...

 

Quite honestly it sounds to me that the main difference between the FD1 and FD2 system is merely the gear ratio and some programming changes. I wonder if someone down the road will hack the software and allow you to change the tamer FD1's programming to make it more FD2 like. Add a lift kit, skid plates and some frame re-inforcement and you have yourself an almost FD2.

It makes sense because then they only have to change one element of the transmission mechanically, the gear ratio, and just alter software. Saves them money in the manufacturing process but at the same time at the marketing end gives them a whole new system to sell at the cost of some software and gears, which is peanuts. Good profit for them.