I have tried on several occasions to use my Hill descent control button but, every time I try, the HDC flashing green light and chime start going off. Im following the procedure in the owners manual. I put it in low range then push the HDC button but, based on the light and chime it thinks im still in high range. I have no other lights on and the traction control works fine. Any thoughts or suggestions on what the problem could be? Its really not something I would use much it just bugs me that it doesnt work. Also, I have been doing some reading on the traction control systems on the disco 2 and supposedly when in low range the computer uses a more aggressive traction control intervention then in high range do to the fact it is less likely to stall the engine. Has any one ever heard this or notice this in off roading situations? Here is the link where I found the info. It addresses the traction control strategies on page 6 under heading " Advanced Transmission" http://www.rimmerbros.co.uk/images/pdfs/discovery2.pdf


any help on the HDC is appreciated.

 

When you start the engine do the ABS and traction control lights come on for the self check?

 

Yes all the lights come on at start up.

 

Assuming you are moving the lever far enough forward to select low range (does the vehicle move when low range is selected? If only neutral, it will not move), you might check the High/Low detect switch on the front output housing on the transfer case.

 

It goes into gear easy and drives like its in low range. Any way to test the detect switch?

 

So you are saying that when in low range the HDC does not engage at all, even if you put the tranny in 1st. gear?
As for the traction control, being operated by the ABS, there is no difference in how it engages, be it high or low range, it is all based on the amount of tire slippage.
Have you recently had your 3 Amigos come on, even for a short while, if you use a scanner on the OBD2, have you ever thrown a 1590 code?

 

As far as the three amigos are concerned, I bought the vehicle after came in on trade at a local independent rover dealer. The lot informed me the 3 amigos was on when it came in on trade but, they had fixed it. I think they said it was something to do with a ground wire. The traction control seems to work fine, when the wheels slip the TC light flicks on and you can hear the abs unit making its noise. You know mike, Im not sure if when in low I was putting it in first or leaving it in drive. I guess I need to retry and see what happens.

 

Okay, I put it in low and in 1st gear and pressed HDC button and it still blinks and chimes. I also tried to switch the trans to manual mode, which is a low range option only and it would not select it. For some reason it is not registering that it is in low even though mechanically it is. Any thoughts? is this the detect switch?

 

It had been a while since I selected low range in mine, so upon coming home tonight, I went through the HDC procedure: low range, HDC button pressed, light comes on blinking and beeping until auto shifter moved from neutral (where it needs to be to change transfer case gears) then beeping stops and light is solid. Auto shifter in neutral regardless of transfer case shifter position causes blinking and beeping. This is all normal, and brings me to a question, which I hadn't thought of:

When you move the transfer case shifter from high gear to neutral, do you get the warning light and beeping of the transfer case being in neutral? It is a light which looks like gears meshing with a line through it just below the HDC light on the upper left corner of the instrument cluster.

If the transfer case neutral warning light does NOT come on, when the transfer case is in neutral (shifting from high to low), my money is on the detect switch.

 

I just went out and checked and I do get the transfer case in nuetrul light and chime. I wonder if the detect switch could still be bad.