The light illuminates green when the master switch is pressed but no cruise speed is active and yellow when cruise control is active.
For MG6. The message centre will display Cruise Set ### MPH (### represents the speed set) or Cruise Control: Standby as appropriate. If a fault is detected, the warning light will flash yellow and the message Cruise Control: Fault will be displayed.
For MG3. When cruise control is set, the target speed is shown in the LCD, The target speed remains displayed until the actual speed achieves this, at which point the LCD reverts to its previous display.