1. Press to switch HDC on and off.
2. Press to increase the set speed.
3. Press to decrease the set speed.
HDC can be selected at speeds below 80 km/h (50 mph).
Manual transmission: HDC can be used in first or reverse gears when in Hi range and in all gears when in Lo range.
Automatic transmission: HDC can be used in D, R or CommandShift 1 when in Hi range and in D, R and all CommandShift gears when in Lo range. When in D, the vehicle will select the most appropriate gear.
Note: HDC is automatically selected by some of the Terrain Response special programs.
To select HDC, press and release the HDC on/off switch (1).
If the HDC lamp flashes, HDC has been selected but is not operating. This is caused by the system’s operating conditions not being met (e.g. vehicle speed too high).
If HDC is deselected while operating, the lamp will flash and the system will fade out, allowing the vehicle speed to gradually increase.
If the vehicle speed exceeds 80 km/h (50 mph), HDC will disengage and the HDC lamp will extinguish.
Note: HDC is automatically deselected if the ignition is switched off for more than 6 hours.
With HDC engaged, the speed of descent can be altered using the cruise control steering wheel switches, as follows:
• To increase speed, press and hold the + switch (2) until the desired speed is achieved.
• To decrease speed, press and hold the − switch (3) until the desired speed is achieved.
When the switch is released, the selected speed will be maintained.
To increase or decrease speed gradually, tap the + or − switch as required. Each tap of the switch will increase or decrease the speed in increments of 0.5 km/h (0.3 mph).
The accelerator pedal can also be used to increase speed, up to the threshold in each gear.
Note: Each gear has a pre-determined minimum speed.
When ascending steep slopes with HDC selected, the vehicle will allow full control to the driver in the normal manner.
If HDC is switched off, the maximum vehicle speed will be limited to allow more accurate control of the ascent.
Do not attempt a steep descent if HDC is inoperative or warning messages are displayed.
In extreme circumstances, the HDC system may cause brake temperatures to exceed their pre-set limits.
If this occurs, the warning HDC TEMPORARILY UNAVAILABLE will be displayed in the message centre. HDC will then fade out and become temporarily inactive.
Once the brakes have reached an acceptable temperature, the message will disappear (or the warning lamp will extinguish) and HDC will, if required, resume operation.
If a fault is detected in the HDC system, HDC FAULT SYSTEM NOT AVAILABLE will appear in the message centre.
If the fault is detected whilst the system is operating, HDC assistance will fade out.
If a fault is detected, contact your Land Rover Dealer / Authorised Repairer as soon as possible.
Descent speed will only increase on a slope steep enough to provide additional momentum. Therefore, use of the + switch on a gentle slope may not increase the speed.
When using HDC in manual transmission vehicles, depressing the clutch pedal will prevent HDC from controlling the speed of descent.
If the brake pedal is depressed, HDC will be overridden and the brakes will operate as normal. When the brake pedal is released, HDC will resume control of the descent.
If HDC is switched off during a descent via the brake pedal, HDC assistance will fade out gradually. This is to prevent loss of control if HDC is switched off in error.
HDC will resume control when switched back on if assistance is still required, but at the speed the vehicle is travelling when the brake pedal is released.
With HDC activated, if the vehicle is stopped on a slope using the foot brake, GRC will become active (except in Terrain Response Sand program).
During a hill ascent, when the foot brake is released, GRC will automatically delay and graduate the brake release to allow the vehicle to move smoothly away.
When descending a hill, a similar brake hold and gradual release is employed to provide a smooth transition into HDC control.
GRC operates in forward and reverse gears and requires no driver intervention.
