I live on a large steep hill, and Ive been trying to figure out how the HDC works with no luck. Ive tried using it while in drive with feet off the pedals, tried in in low range (3 and 2) and same results: The truck just speeds up and gains momentum, by the time I reach the bottom of the hill the truck is doing 45-50 MPH! Seems utterly useless. When I puch the HDC a green blinking light appears and continues to blink and beep for as long as the feature is engaged. Ive got no known faults in the system and no warning lights coming up.

So what is the procedure for engaging the HDC? Come to complete stop at top of hill, engage HDC and steer? Or do I need to put the transmission in 3rd, 2nd or 1st gear along with the HDC? Or do I engage the low range shifter along with HDC? Engaging the low range shifter is the ONLY thing I have not tried yet. I did do a search and found different opinions on how to properly engage the system...



Regarding the transmission. Ive been testing the low gears (3rd, 2nd, 1st) while going down my hill and it seems to me that 3rd is also useless, 2nd gear occasionally slows the vehicle down but 1st is the only gear that absolutely slows the vehicle down all the way as it should. It feels as though my gears are not functioning properly.


Lastly on occasion while shifting fast (sudden lane change at last minute) or driving over bumps of soil I can hear a loud noise and feel a vibration from underneath the vehicle. Difficult to explain the sound but Id say it sounds like a mechanical object is unwinding with rapid speed. The sound tends to last oh but 4 seconds as it winds down then the noise goes away. A minor vibration can be felt during the duration of the noise. This has only occurred at low speeds around 5-10 MPH.


Found this video on youtube and it seems Im not the only one having problems using the HDC. My truck does the same thing as his, travels to fast down hills instead of slowing the vehicle down. I dont trust it.

 

Yep the transfer case has to be in low.

 

Are you trying with the t/case in low range, that is the only way it will work as long as you don't have the 3 Amigo's on?

 

Forgive my ignorance: when you say the transfer case, are you refering to the hi/low/CDL shifter? Or the low gears on the automatic shifter (3rd, 2nd, 1st)? I have not tried engaging the hi/low shifter while using the HDC as of yet, but I will try it tomorrow on my way home. With this in mind should I also use the low gears? Or will the low range shifter + HDC suffice?

 

You may want to read your owners manual.
Put the t/case in low range and depending on how slow you want to go, 1 st gear for the slowest.

 

Thank you, HDC may work yet ^^ if so I look forward to it cause my hill is no fun when its covered in snow, slush and ice.

Any thoughts regarding the other symptoms I described above?

 

Yeah, you're just in normal drive.

HDC only take effect when the transfer case is in low range. Once you've switched the transfer case to low range, you can select gearing on the shifter to further control your speed.

 

I will say that hdc works pretty well, but I've only used it in the summer on mostly dry trails just to see how it did.

I'd be very careful trying to use it on an icy paved road. It may work well, but be sure to test it a few times so you know how it does and how fast you'll be going.

 

I've tried it on Very Loose Dirt, Sand Dunes, and on Snow Covered Hills. It works FABULOUSLY on all! It holds 5mph in all cases and keeps me going in the right direction. Only concern is using it too much as it does work the brakes a LOT. On a Super Long Hill (1/2 mile or more), I would recommend using low range and low gear, no HDC.

I've never had the issues shown in the above demo, and I've used it many times now. Maybe his system is in need of repair? Here is a demo of mine in use. The hill is actually steeper than the video appears, and Much Bumpier than it appears. You can hear my keys knocking around due to bumping.

I believe I'm in Low Range, but in Drive and it still holds 5mph.

 

Pleased to say that the HDC works as it should in my Disco! Although it does not make the noises described by other members "sounds like transmission is about to fall out", mine is mostly quit besides the constant green light beeping on the dash. Thanks guys, glad to know how to use the system as I will need it very soon.