Descent Control

Descent control mode attempts to keep the vehicle below a set speed on a downhill slope by using all available recuperative braking stages.

To activate descent control mode, remove your foot from the accelerator pedal, set the right-hand stalk switch to any of the three 'on' positions (1, 2, or 3) as shown in Fig. and then use the set or resume buttons to set the vehicle speed. The descent control mode telltale, shown in Fig. illuminates on the driver display when descent control mode is active.

Fig. 1, Descent Mode Telltale

As descent control mode is not designed to keep the vehicle above any set speed, it is possible to eventually coast to a stop unless the accelerator pedal is applied or the right-hand stalk switch is moved to the 'off' position (0).

If the accelerator pedal is applied, the descent control mode resumes when the accelerator pedal is released.

Moving the right-hand stalk switch to the 'off' position deactivates descent control mode and resumes cruise control, using the descent control set speed as the cruise control set speed.

In the case of very steep grades, recuperative braking may not be able to maintain the vehicle speed below the set speed. In these circumstances, the driver can apply the service brakes to slow the vehicle below the set speed without dropping out of descent control mode. However, after releasing the service brakes, a new cruise set speed lower than the original set speed is set. The driver is informed of this new set speed by a message on the driver display.

Off

Low

Medium

High

Fig. 2, Recuperative Braking Positions