Member Since: 12 Jan 2016
Location: Surrey / SW London
Posts: 2136
That "might" be what the described run away is. The car might increase speed to get traction then try to reduce speed again!
I haven't done a lot of driving in slippery stuff in the D4. I've done a lot in my old 90 defender as I lived in the Alps for 3 years.
I often found 1L too short when it's very slippery as it can be harsh when on and off the gas and cause jolting etc, which can be enough to break traction. You need to be very gentle with the controls.
Once the car starts to slide, you usually need a lot of space to sort it out, which is usually the problem!
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3rd Apr 2017 6:07 am
L319
Member Since: 14 Dec 2013
Location: Herefordshire
Posts: 2079
If it starts to slide you need to open the throttle to get the vehicle & wheel speeds matched and then slowly close it again. , but you need plenty of space & its rather counter intuitive the first time you need to do it. It s best to find a space to try, rather like having a go on a skid pan, to get the hand of it. HDC is very good but if there is insufficient grip it will go!
3rd Apr 2017 7:57 am
DG Site Moderator
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50930
garrycol wrote:
The car might slide a bit but will not run away
In the right (or wrong) conditions it will. My schoolboy error was that the slope was too steep, far too wet and once sliding the corrective action of trying to move the wheels onto more solid ground just pulled the back of the motor around and bang ! I think if I hadn't hit something half way down then I would have been really hurtling to the bottom 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
3rd Apr 2017 8:06 am
JPW
Member Since: 19 Mar 2007
Location: Essex
Posts: 217
I thiught I'd seen something about HDC being affected by high / low range.
the owners manual says;
During a descent, HDC will maintain a target speed of up to a maximum of 20 km/h (12 mph) in low range, and 30 km/h (19 mph) in high range.
3rd Apr 2017 8:51 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72742
In some conditions even the minimum speed that you can dial in is scarily fast. The manual didn't anticipate the crazy things we do with these cars. You have a choice, feet off the pedals and go too fast or control the decent using HDC and the brakes. Driver's choice.
3rd Apr 2017 9:01 am
garrycol
Member Since: 06 Dec 2010
Location: Canberra
Posts: 1114
Rock crawl, 1st gear low range - foot off the accelerator and with HDC on it will not kick in - in that configuration the torque converter is locked and you have full engine braking - on the steepest, slipperyest hills the car will go slower than with HDC alone. Plus you dont have all the racket and shuddering that HDC invokes.
You don't need HDC.
3rd Apr 2017 9:36 am
Reginald Molehusband
Member Since: 17 Nov 2009
Location: West Calder
Posts: 632
On a steep, slippery descent, once you've lost grip and the speed of the vehicle exceeds the speed of the wheels you are by definition 'out of control.' To regain control the wheel speed has to match the vehicle speed and the quickest way to achieve that it to speed-up the wheels a little.
If you're relying on HDC this may be achieved using the + button, otherwise try a little accelerator. As soon as you are back in control you can work on slowing down again, but you can't do anything about speed and probably not much about direction whilst you are out of control.
It is one of the most counter-intuitive things to do in a car: going too fast so accelerate, but it does work if you can make yourself do it.
Of course, a proper recce before you start the descent could save a lot of embarassment. 2016 D4 Landmark SDV6 (Euro6), Zanzibar (late run D4)
2009 D4 HSE TDV6, Bali blue (first run D4)
2007 RRS TDV8 HSE, some blue
.
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
DSL wrote:
DrRobH wrote:
Pressing the brake will cancel HDC won't it?
No, it doesn't.
Yes it does, or at least you can consider it suspended. HDC is moderated by the right foot which may require some extra throttle to regain grip. HDC speed is controlled by gearing and the cruise buttons. For vehicles without cruise control the HDC can become self-defeating as the default speed may be too high for the conditions and people then start braking instead.
There are instructional videos on how it all works on youtube so worth a look.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50930
Reginald Molehusband wrote:
Of course, a proper recce before you start the descent could save a lot of embarassment.
yes ...and this
TBF in my case someone had just gone (hurtled) down before me ... but poor comms signal meant that I heard a cracking, cutting out "don't come down" from the previous driver as " %$&%%$£ come down" 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
3rd Apr 2017 11:00 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72742
ISTR I'd seen Chris200100 go down with not a lot of control, decided to take the chicken route then saw you being supported by that tree. One of my better decisions.
3rd Apr 2017 11:09 am
DG Site Moderator
Member Since: 12 Dec 2005
Location: The Gaff
Posts: 50930
Slimer nearly lost it going down before me .... shining up the sloppy rainsodden mud smoothing my path 21 year LR veteran > D2 GS 2003 > D3 S 2006 > D3 HSE 2009 > D4 HSE 2013 > D4 HSE 2015 > D5 HSE 2018 > DS HSE R-Dynamic P300e 2021
3rd Apr 2017 11:40 am
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72742
He could have taken the trees away. Would have made things even more interesting, as long as I wasn't at the bottom. Got some pics of the recovery operation, but no idea where.
never knew that about the +/- buttons ... have to find a suitable hill to try it !.
Dean
====================================
2011 D4 XS - OBD port protection, RLD spare wheel protector, All LED interiors lights, Timed Climate enabled, iiD tool paired.
2011 D4 Landmark - Stolen from same dealer before I paid for it
2011 D4 GS - Stolen whilst at dealer ... All LED interiors lights, DRLs, Spare Wheel protector.
1996 300Tdi - Eaten by tin worms
3rd Apr 2017 12:03 pm
Discologist
Member Since: 19 May 2014
Location: Yorkshire
Posts: 537
DG wrote:
Reginald Molehusband wrote:
Of course, a proper recce before you start the descent could save a lot of embarassment.
yes ...and this
TBF in my case someone had just gone (hurtled) down before me ... but poor comms signal meant that I heard a cracking, cutting out "don't come down" from the previous driver as " %$&%%$£ come down"
Ah, the Crimson Tide school of comms.
3rd Apr 2017 6:18 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72742
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