Hill Descent Control
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4th Gear
Joined: Oct 2010
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Hill Descent Control
I'd like to be able to use HDC for towing purposes and have active braking ready to use but I am getting the Green indicator lamp flashing with a tone. In the manual this is because I'm supposedly not meeting one of the requirements for HDC to work... which I think I am (Low Range, in Gear). The driver's manual says that this happens with perhaps the car senses too much heat in the brakes for overdone use but it is winter right now.
If anyone know's more about this flashing light (there's a name for it it just escapes me right now) that would be great! I look forward to using HDC where in the past I thought I had been. For some reason I thought the Discovery version was just more primitive than the Range Rover and didn't think twice about how fast I would go down hills only using low range engine braking.
Thanks very much,
Peter
2002 Discovery II SE7 135000 - w/o self leveling - recently replaced shuttle valve switch proving successful fix of three lights - current evap leak, o2 fault, knock sensor fault... likely due to valve cover leak.
If anyone know's more about this flashing light (there's a name for it it just escapes me right now) that would be great! I look forward to using HDC where in the past I thought I had been. For some reason I thought the Discovery version was just more primitive than the Range Rover and didn't think twice about how fast I would go down hills only using low range engine braking.
Thanks very much,
Peter
2002 Discovery II SE7 135000 - w/o self leveling - recently replaced shuttle valve switch proving successful fix of three lights - current evap leak, o2 fault, knock sensor fault... likely due to valve cover leak.
TReK
Joined: Nov 2009
Posts: 2,433
Likes: 5
From: Woodway, WA
I highly doubt the HDC will work very well with something in tow, it's an off-road feature. But when you say you want to use it for "towing purposes", what exactly do you mean???
You need to be in low range, then shift into 1, don't touch the brakes or the gas pedal, or the HDC will disengage. It will probably work in 2 or 3 as well, but I've never used it in those gears, and I don't have my manual handy.
You need to be in low range, then shift into 1, don't touch the brakes or the gas pedal, or the HDC will disengage. It will probably work in 2 or 3 as well, but I've never used it in those gears, and I don't have my manual handy.
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4th Gear
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Well that's fine I guess I'll figure out what I can use it for once it's working. My primary concern is that flashing green light with tone. It doesn't work. I know how I'm supposed to activate it meaning low range 1st gear should at least work but my dealer friend and I tested it in the parking lot by accelerating and seeing if it did anything and he said that the abs is supposed to go crazy and slow the vehicle. He told me he'd look into some bulletins and I figured in the meantime I'd ask around here.
Green indicator flashing and pinging??
Green indicator flashing and pinging??
Mudding
Joined: Nov 2010
Posts: 179
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From: Placerville CA
I am more familiar with other makes of Traction Control, which will not try to work if there are any DTC in the engine. I know that DC is supposed to only be applying the brakes but it is all interconnected. I used my DC last weekend just to make sure it functioned and it worked fine in D, lo-range.
Winching
Joined: Dec 2009
Posts: 685
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This won't work unless the vehicle is actually DESCENDING A HILL. Ie. hill descent control.
Simply flooring it in a parking lot won't engage the system; it's more complicated than that, I believe it has maximum engagement speeds as well. It senses vehicle acceleration AFTER HDC is engaged, due to gravity (as someone else mentioned, stepping on the gas will disengage the system).
Sounds to me like you're not using it the way it was meant to be used; as I mentioned above, the system will only apply brakes if the vehicle is accelerating due to external forces after the system is engaged.
Simply flooring it in a parking lot won't engage the system; it's more complicated than that, I believe it has maximum engagement speeds as well. It senses vehicle acceleration AFTER HDC is engaged, due to gravity (as someone else mentioned, stepping on the gas will disengage the system).
Sounds to me like you're not using it the way it was meant to be used; as I mentioned above, the system will only apply brakes if the vehicle is accelerating due to external forces after the system is engaged.
what is the light that is blinking? you need to be in lo-gear and the transmission needs to be in 1, you need to be rolling down a hill and then turn the wheel off the road and as you go over the grass and rocks on the side of the road you will feel the HDC apply the brakes. if you just roll down a smooth hill it will just pick up speed.
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4th Gear
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If any of you are reading my question.......... I am in Low Range. I am in first gear.
I am not asking how Hill Decent Control works, it happens to be that real land rover bulletins have noted a good test is in a parking lot, the car has no idea if it is on a hill it only knows slipped wheels from non slipped wheel and speed.
DiscoMike please help me
I am not asking how Hill Decent Control works, it happens to be that real land rover bulletins have noted a good test is in a parking lot, the car has no idea if it is on a hill it only knows slipped wheels from non slipped wheel and speed.
DiscoMike please help me
TReK
Joined: Nov 2009
Posts: 2,433
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From: Woodway, WA
Got it, you are in 1 and in LO....
NOW : Which green indicator light is flashing? The "S" light, the "M" light? And when does the light come on?
It seems so far we are not understanding exactly what you are asking, because everyone thinks you're asking about HDC, and you haven't told us which green light is blinking?
We really want to help, we promise
But if you only want Mike's help, try sending him a PM with your phone number.
NOW : Which green indicator light is flashing? The "S" light, the "M" light? And when does the light come on?
It seems so far we are not understanding exactly what you are asking, because everyone thinks you're asking about HDC, and you haven't told us which green light is blinking?
We really want to help, we promise
But if you only want Mike's help, try sending him a PM with your phone number.
Winching
Joined: Dec 2009
Posts: 685
Likes: 41
If any of you are reading my question.......... I am in Low Range. I am in first gear.
I am not asking how Hill Decent Control works, it happens to be that real land rover bulletins have noted a good test is in a parking lot, the car has no idea if it is on a hill it only knows slipped wheels from non slipped wheel and speed.
DiscoMike please help me
I am not asking how Hill Decent Control works, it happens to be that real land rover bulletins have noted a good test is in a parking lot, the car has no idea if it is on a hill it only knows slipped wheels from non slipped wheel and speed.
DiscoMike please help me
It's designed to maintain a steady speed, not slow you down after you press the button.
For example, if you accelerate in a parking lot and press the button.. a number of things will prevent it from working; too fast to engage, the vehicle isn't actually accelerating, etc.
You still haven't told us what you actually want to use the feature for, that would be very helpful.
To put an end to all of this, since you don't seem to believe me. As per RAVE manual:
When selected on, HDC is enabled in all forward gears and reverse provided:
l Vehicle speed is below 31.3 mph (50 km/h).
l The transfer box is in low range.
l On manual gearbox vehicles, the clutch is engaged.
If HDC is selected outside the above conditions, the HDC information warning lamp flashes and the audible warning sounds continuously.
l Vehicle speed is below 31.3 mph (50 km/h).
l The transfer box is in low range.
l On manual gearbox vehicles, the clutch is engaged.
If HDC is selected outside the above conditions, the HDC information warning lamp flashes and the audible warning sounds continuously.
Additionally, this explains (in a much better way) what I was trying to tell you, about how the system works only if the vehicle is being slowed by external forces.
The deceleration rate is dependent on the speed differential between initial vehicle speed and the target speed.
The target speed increases as the accelerator pedal is pressed, from a programmed minimum with the acceleratorpedal released, up to a maximum of 31.3 mph (50 km/h). For any given accelerator pedal position, while travelling uphill or on level ground the target speed is always greater than the corresponding vehicle speed, which allows the vehicle to be driven normally without HDC intervention. However, when travelling downhill, the gravitational effect on the vehicle means that for any given accelerator pedal position the target speed is less than the corresponding vehicle speed, and HDC intervenes to limit vehicle speed to the target speed.
The target speed increases as the accelerator pedal is pressed, from a programmed minimum with the acceleratorpedal released, up to a maximum of 31.3 mph (50 km/h). For any given accelerator pedal position, while travelling uphill or on level ground the target speed is always greater than the corresponding vehicle speed, which allows the vehicle to be driven normally without HDC intervention. However, when travelling downhill, the gravitational effect on the vehicle means that for any given accelerator pedal position the target speed is less than the corresponding vehicle speed, and HDC intervenes to limit vehicle speed to the target speed.
Tell your friends on the other forum that they were misinformed (and obviously haven't tried it for themselves lol)
Last edited by EstorilM; Dec 15, 2010 at 02:43 PM.