Abs System Control

The ABS module controls several functions and adjusts the operating parameters of these functions to optimize the selected Terrain Response program.

Traction Control 

Traction control uses different slip/acceleration thresholds to improve traction and vehicle composure. For example, the system sensitivity is increased on slippery surfaces such as wet grass or snow to reduce wheel spin. If wheel spin was allowed in these circumstances, loss of traction may result from surface damage (wet grass) or the car being unable to move (snow) due to wheel spin.

Dynamic Stability Control 

If DSC is switched off (with the DSC switch adjacent to the Terrain Response rotary control) when using a Terrain Response special program, if the special program is subsequently changed for a different program, DSC is automatically switched back on.

The DSC uses different threshold values for the selected program to automatically reduce DSC intervention, removing the requirement for the driver to disable the DSC system in order to reduce engine intervention which is sometimes induced in extreme off-road conditions. In extreme sand conditions, there may be an additional benefit of disabling the DSC function using the DSC switch in addition to selecting the sand program.

In the Mud/Ruts program the DSC system is calibrated to tolerate a higher 'yaw' threshold. This allows a greater differential between the actual and desired wheel turning behavior before DSC intervenes. This allows the DSC system to ignore the effect of ruts 'jarring' the car or adjusting the front wheel steering angle.

The Terrain Response system can alter the balance between engine and brake intervention. For example, when the sand program is selected, the DSC system reduces its reliance on engine intervention and increases the use of brake intervention to maintain the vehicles momentum and prevent it from becoming bogged down if wheel slip is detected.

Hill Descent Control 

HDC is automatically switched on or off and target speeds are adjusted in response to the Terrain Response program selected. The responsiveness of the HDC function is also increased where required.

Automatic operation of HDC aims to assist the driver by switching the system on or off when it is of most benefit. HDC is only automatically switched on when the mud/ruts program is selected. HDC is not automatically selected in other programs.