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Took a low roof empty Promaster for an off road test. Conditions were cold about 5 F with about 3" of dry snow.

Noticed it was very noisy on gravel with stones ejecting from the tires banging on the bottom of the van. Under coating, sub floor, insulation and paneling would be helpful if you plan to drive much on gravel roads.

Off road through level fields, dirt trails and up to 10" snow drifts were no problem. All was looking great until we tried an incline where the Promaster spun out with only one wheel spinning. Attempted the incline several times and always spun out with only one wheel spinning. Did not try it with the with the Traction Control turned off. Do not know if that would make a difference.
 

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Is flying rocks hitting the underbody are an issue, then that could be because it has no mud flaps, usually it would stop most of it.
 

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having the traction control off might have helped a bit

but having a van that is FWD going up a hill that is covered in snow isn't going to get you anywhere in general. Unless you have snow tires.
 

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having the traction control off might have helped a bit

but having a van that is FWD going up a hill that is covered in snow isn't going to get you anywhere in general. Unless you have snow tires.
Would a RWD van be any better under same conditions. If so, how or why?
 

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That's kinda disappointing to hear. It sounds as if the traction control wasn't working since it allowed one wheel to spin.

Did you hear it working? There would be about a 10 Hz pulsing noise, similar to the ABS working if you slammed on the brakes in snow. Also, was a light flashing on the dash? Or a message on the center screen such as "Traction Active" or "Stability Active?"
 

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I learned to disable TC at times and learn how to control my vehicles with out it, if you do that, it can save you at times and make life less of a headache. TC isn't always the best.
 

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Discussion Starter #8
That's kinda disappointing to hear. It sounds as if the traction control wasn't working since it allowed one wheel to spin.

Did you hear it working? There would be about a 10 Hz pulsing noise, similar to the ABS working if you slammed on the brakes in snow. Also, was a light flashing on the dash? Or a message on the center screen such as "Traction Active" or "Stability Active?"
Sorry I did not notice any lights flashing or messages on the dash. My main interest was to determine if the Brake Lock Differential actually locked the differential and forced both wheels to spin the same as a real locking differential.
In this case it did not. If it did, it would be a very useful feature and reduce the need for AWD or 4WD.
 

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Brake Lock Differential?
Here is an explanation of what it's supposed to do, or how it works. Also discusses briefly what drivers need to do differently to get the most out of the system.

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


The first time I recall seeing this type of traction control was on a TV commerical for the then newly introduced Mercedes Benz SUV. That vehicle had AWD or 4WD but used the brakes on wheels without traction to force the wheels with greater traction to propel the vehicle. I thought it was clever use of vehicle brakes to accomplish almost the same thing as actual locking differentials.
 

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Does the ProMaster claim to have "Brake Lock Differential?" I thought it only claimed to have Stability Control (of which Traction Control is a feature subset).
 

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In Italy the Ducato has two different options of the TC. The first one is a simple TC that at the first reduce the throttle and after use brakes to stop the spinning of the wheel with less traction. This means that on a snowy hill you risk to loose too much speed and stop the climbing...often is better to deactivate this kind of TC on the fresh snow.
The second option is a TC that simulates an auto locking differential keeping the revs of the engine high to mantain the speed.
 

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Many of these different names (“Traction Plus,” “Brake Lock Differential”, “Electronic Differential Lock”) are just marketing names for the same thing, namely a different operating mode of the Electronic Stability Control (ESC, or outside of North American usually called Electronic Stability Program or ESP).

When fully operational, ESC (ESP) will apply the brakes AND cut engine torque to try to reduce the speed of the spinning wheels to that of the non-powered wheels (rear wheels, in the case of the ProMaster). While this is probably the safest response such a system can have, it is not the best response to prevent a vehicle from getting stuck or to get it moving if it is already stuck, in low-traction situations. In such cases, a little extra while speed (relative to the non-driven wheels) is usually helpful. In addition to this, ESC will also monitor vehicle yaw (rotation about an imaginary vertical axis) and steering wheel position, and will apply individual brakes to try to maintain the desired path of the vehicle at higher vehicle speeds. This is a little off topic, since this thread was started with a description of the ProMaster’s apparent poor performance in trying to climb a hill in low-traction, low-speed situation.

OK, so back on topic. I read the owner's manual to investigate whether the ProMaster is claimed to have Electronic Differential Lock (or whatever we want to call it). A link to it was posted on another thread:

http://www.promasterforum.com/forum/showthread.php?t=11898

Here's a quote from page 208:

When in the “Partial Off” mode, the TCS portion of ESC,
except for the “limited slip” feature described in the TCS
section, has been disabled and the “ESC OFF Indicator
Light” will be illuminated. When in the “Partial Off”
mode, ESC will operate without engine torque management.
This mode is intended to be used if the vehicle is in
deep snow, sand or gravel conditions and more wheel
spin than ESC would normally allow is required to gain
traction. To turn ESC on again, momentarily press the
“ESC Off” switch. This will restore the normal “ESC On”
mode of operation.

I interpret this to mean that the ProMaster does indeed have this feature, but that Ram chooses to use neither the names "Traction Plus" nor "Brake Lock Differential" to describe it. Instead, Ram describes it as using only the Traction Control portion of ESC. It is achieved by pushing the “ESC Off” button to switch to "ESC Partial Off" mode. That’s sort of counter-intuitive to label the button “ESC Off,” but I assume that is due to trying to align with an SAE standard or recommended practice for labeling controls. Apparently, like most modern vehicles, it is not possible to fully turn off the ESC, only to change its operating mode. Some OEMs dance around the fact that you aren't REALLY able to turn the system off in their owner’s manuals. Or, if they do let you turn it off completely, they make you jump through hoops, such as shifting to neutral, then pushing and holding the button for five seconds, then rubbing your belly for ten seconds, etc.. But kudos to Ram for using accurate language of “ESC partial off” in describing the operating mode.

So, knowing all this, it would be interesting to repeat the experiment, both in full ESC active and with only Traction Control active (“ESP partial off”), and then consider the difference (if any is observed) in vehicle behavior.
 

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....cut.....

Here's a quote from page 208:

When in the “Partial Off” mode, the TCS portion of ESC,
except for the “limited slip” feature described in the TCS
section, has been disabled and the “ESC OFF Indicator
Light” will be illuminated. When in the “Partial Off”
mode, ESC will operate without engine torque management.
This mode is intended to be used if the vehicle is in
deep snow, sand or gravel conditions and more wheel
spin than ESC would normally allow is required to gain
traction. To turn ESC on again, momentarily press the
“ESC Off” switch. This will restore the normal “ESC On”
mode of operation.

.....cut.......
Chris, can you post what it says about the "limited slip" feature described in the TCS section. That's the part that sounds most interesting to me.
 

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Here ya go, from page 205....


Traction Control System (TCS)
The Traction Control System (TCS) 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
functions similarly 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
the ESC is in the “Partial Off” mode.

The “ESC Activation/Malfunction Indicator Light” (in
the instrument cluster) will start to flash as soon as the
tires lose traction and the wheels begin to spin. This
indicates that the TCS is active. If the indicator light
flashes during acceleration, ease up on the accelerator
and apply as little throttle as possible. Be sure to adapt
your speed and driving to the prevailing road conditions,
and do not switch off the ESC or TCS.
 
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