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HDC details
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Baltazar
 


Member Since: 17 Apr 2015
Location: Slovenia
Posts: 21

Slovenia 2016 Discovery 4 3.0 TDV6 S Auto Loire BlueDiscovery 4
HDC details

I am thinking about buying a new D4 (will be my first Discovery, currently a Defender => A LOT of hesitation).

Two questions about Hill Descent Control:

- The user manual says that HDC speed can be controlled by Cruise control + & - buttons. How do I do if I have no Cruise control (which is a possible configuration in my market)?

- Does HDC only apply brakes to limit the speed or does it select a lower gear to take advantage of engine brake effect?
  
Post #14695436th May 2015 8:54 pm
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Cantthinkofone
 


Member Since: 21 Nov 2013
Location: Binfield
Posts: 37

England 2010 Discovery 4 3.0 TDV6 GS Auto Stornoway GreyDiscovery 4

I also don't have cruise control and asked this question on a Land Rover experience day, unfortunately no one knew the answer. Having now tried it on a few occasions, there seems to be a set speed in each gear so I have put it into command shift and then just select an appropriate gear for the hill, if you want to slow down a bit select a lower gear and so on. As far as I'm aware HDC will not change the gear for you, at least not in my gs model.
  
Post #14702407th May 2015 11:40 pm
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L319
 


Member Since: 14 Dec 2013
Location: Herefordshire
Posts: 2080

United Kingdom 2005 Discovery 3 TDV6 HSE Auto Buckingham BlueDiscovery 3

You can increase the HDC intervention speed with the throttle on vehicles with cruise, I assume its the same without cruise.
  
Post #14703218th May 2015 6:54 am
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swansty
 


Member Since: 21 Sep 2008
Location: Northern Ireland
Posts: 918

Northern Ireland 2010 Discovery 4 3.0 TDV6 XS Auto Zermatt SilverDiscovery 4

L319 wrote:
You can increase the HDC intervention speed with the throttle on vehicles with cruise, I assume its the same without cruise.


Pressing the throttle overrides the HDC, which isn't quite the same as increasing the speed it will maintain. I would assume without CC buttons, it has a default speed which may vary depending on gear selected. If you are requiring HDC to be functional, I suspect you would want to be manually selecting low 1st or 2nd anyway. Its an aide to good driving practices, not a replacement.
  
Post #14703708th May 2015 8:28 am
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Baltazar
 


Member Since: 17 Apr 2015
Location: Slovenia
Posts: 21

Slovenia 2016 Discovery 4 3.0 TDV6 S Auto Loire BlueDiscovery 4

It's a bit clearer now, thanks. What about my second question?
  
Post #14707048th May 2015 8:10 pm
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swansty
 


Member Since: 21 Sep 2008
Location: Northern Ireland
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Northern Ireland 2010 Discovery 4 3.0 TDV6 XS Auto Zermatt SilverDiscovery 4

There might be more info on this in the site wiki section. I don't think it will change down the gears otherwise it wouldn't work in a manual. That's why I would recommend assessing the downhill, select an appropriate gear, and use hdc as an aide. It is absolutely amazing how it works to control the vehicle at such a low speed on the steepest and slippiest of hills. Just remember though, it can't defy gravity and if the wheels start sliding you may need to throttle slightly to keep the wheels turning and retain control.
  
Post #14708028th May 2015 11:37 pm
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M3DPO
 


Member Since: 22 Sep 2010
Location: Notts.
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England 2014 Discovery 4 3.0 SDV6 HSE Lux Auto Corris GreyDiscovery 4

It works on the abs brake system, along with reaction control.
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It goes where others don't. 
 
Post #14708219th May 2015 7:20 am
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BLFarrar
 


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France 2006 Discovery 3 TDV6 HSE Auto Lugano TealDiscovery 3
Puzzled..?

All my LR vehicles that have had or have HDC are autos....so HDC is simple foot off the pedals & let the LR coast down whatever's in front.
........the HDC makes the odd noise & limits the speed - OK...the engine is at tick-over & doesn't stall.
So:
In a manual LR I trust you have to be in a low gear ?
but with feet off both pedals in a low gear with HDC do you have the risk of stalling ?
or do you put transmission into N ?

In an auto the HDC works in forwards or reverse or with the transmission in N...its one thing thats explained & demonstrated on LR experience courses

Disco 3/4 HDC works in high or low ratio....as it should.
Disco 2 HDC only worked in low ratio...which was as well as when my D2's HDC system failed all I had to do was use the gears to control the descent - as per usual LR methods
F'lander only has one transmission ratio anyway - so when you use the button feet off pedals & it works at one speed only about 5mph ish
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Post #14708239th May 2015 7:36 am
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jeepmadmike
 


Member Since: 18 Jan 2014
Location: Devon
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United Kingdom 2014 Discovery 4 3.0 SDV6 Commercial Auto Firenze RedDiscovery 4

I'm not a big fan of HDC for anything challenging, but nor have I ever been a gearbox down hill off road person either I just use the brakes - if you know what your doing you can have far greater control
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Post #147317813th May 2015 8:25 pm
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tayaste
 


Member Since: 15 May 2013
Location: Chester
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United Kingdom 2008 Discovery 3 TDV6 HSE Auto Stornoway GreyDiscovery 3

Really? Surely you must be using the engine to keep your pace down ? You wouldn't tackle a steep hill in neutral and just rely on your brakes to keep you on course? Would you ?
   
Post #147318013th May 2015 8:28 pm
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DaveDisco3
 


Member Since: 29 Apr 2014
Location: Gretton, Northamptonshire.
Posts: 597

United Kingdom 2005 Discovery 3 TDV6 HSE Auto Tonga GreenDiscovery 3

Surely greater control is with gears engaged, hdc or no hdc from my experience.
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Post #147319713th May 2015 9:04 pm
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galwaygreen
 


Member Since: 30 Oct 2011
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United Kingdom 2016 Discovery 4 3.0 TDV6 Graphite LE Auto Loire BlueDiscovery 4

surely hdc comes off if you touch the gas
  
Post #147322713th May 2015 9:37 pm
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Baltazar
 


Member Since: 17 Apr 2015
Location: Slovenia
Posts: 21

Slovenia 2016 Discovery 4 3.0 TDV6 S Auto Loire BlueDiscovery 4

tayaste wrote:
Really? Surely you must be using the engine to keep your pace down ? You wouldn't tackle a steep hill in neutral and just rely on your brakes to keep you on course? Would you ?


I also think so, that's why I was asking if HDC uses brakes or engine to slow down. If you put gearbox in S and use shift paddles, you can manually select which gear is engaged, right?
  
Post #147366914th May 2015 8:19 pm
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Naks
 


Member Since: 12 Jul 2010
Location: Stellenbosch, Republic of the Western Cape
Posts: 759

South Africa 2011 Discovery 4 3.0 SDV6 SE Auto Fuji WhiteDiscovery 4

hi guys, quick question about the HDC:

I tried it in our driveway and down our steep road. It works, and pressing the CC+ and CC- buttons increases and decreases the speed, but it doesn't display what the set speed is.

Any way to show this? I think it would be a good idea to know what the set HDC speed is at all times.
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Post #155263229th Oct 2015 8:21 am
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L319
 


Member Since: 14 Dec 2013
Location: Herefordshire
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United Kingdom 2005 Discovery 3 TDV6 HSE Auto Buckingham BlueDiscovery 3

On my D3 the HDC intervention speed can be altered with the throttle . With HDC switched on and I want to maintain say 15MPH , I just open the throttle until the speed reaches 15mph and then hold it at that position. If the speed increases due to the hill the HDC cuts in to maintain 15mph. Opening the throttle doesn't cut the HDC out. Agree it is very poor practise to just use the HDC and not engage a low gear. Eventually the HDC will overheat and reduce/ cut out which is the last thing you need on a long decent.
  
Post #155266129th Oct 2015 9:57 am
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