Controlling the Adaptive Cruise Control
Controlling the adaptive cruise control
Controlling the adaptive cruise control
Note! Closing velocity module (CVM) (4/125) only on S60 (11-), V60 and XC60, as well as from model year 2012 also on S80 (07-), S80L, V70 (08-), and XC70 (08-).
The function adaptive cruise control is an extension of the existing cruise control. If there is no vehicle ahead, the speed will remain unchanged just like for conventional cruise control. Speed is set by the driver in a similar way to conventional cruise control.
If there is a vehicle ahead traveling at a lower speed than the set speed, the speed will adjust itself automatically so that the set time gap to the vehicle ahead is attained. In this case, the adaptive cruise control in Forward Sensing Module (FSM) controls the Engine control module (ECM) and, if necessary, also Brake control module (BCM) to maintain the set time gap.
The time interval to the vehicle in front is set by the driver in five steps, in the interval 1 to 2.5 seconds.
When the system is activated, the last selected interval from the previous driving cycle is used.
To change the interval setting, the driver presses one of the buttons on the Steering wheel switch left (SWSL) to increase or reduce the interval. Steering wheel switch left (SWSL) transmits information via LIN communication to Central electronic module (CEM) (4/56), stating which button has been activated. The Central electronic module (CEM) forwards the information via the CAN network to the Forward Sensing Module (FSM) (4/80).
On vehicles with manual transmission the function adaptive cruise control is limited to a speed higher than approx. 30 km/h.
S60 (11-), V60 as well as XC60 (X60 from structure week 201046) as well as from model year 2012 also S80 (07-), S80L, V70 (08-), and XC70 (08-) - all with automatic transmission - have a function making it possible to adapt the speed to the vehicle in front even below 30 km/h. Should the vehicle in front stop, the adaptive cruise control will stop the vehicle and hold it still using the service brake. To activate the cruise control below 30 km/h, a vehicle in front is required to be within a reasonable distance. Note that the lowest speed that can be programmed for the cruise control is 30 km/h - even if the cruise control is able to follow another vehicle down to a standstill, a lower speed cannot be selected.
The service brake will only hold the vehicle at a standstill for max. 120 seconds, after this the parking brake automatically takes over the responsibility for holding the vehicle stationary. The parking brake will also be applied automatically when the adaptive cruise control has followed another vehicle to a stop and the driver door opens, the seatbelt is unbuckled, the engine is turned off, or if a system failure occurs. When the vehicle in front drives off, and your own vehicle has been stationary for a shorter time than 3 seconds, the adaptive cruise control will activate automatically. However, if your own vehicle has been stationary for a longer time than 3 seconds, the driver has to reactivate the adaptive cruise control for the vehicle to follow. Reactivation is done by pressing the resume button or with a light touch on the gas pedal.
The cruise control be disengaged temporarily due to certain driver actions:
- using the service brake
- pressing down the clutch pedal for longer than 1 minute
- moving the gear selector to neutral position (automatic transmission)
- the driver maintains a higher speed than the set speed for longer than 1 minute.
Thereafter the driver has to control the speed. A temporary speed increase with the gas pedal, e.g., when overtaking, does not affect the cruise control's setting - the car returns to the latest stored speed when the gas pedal is released.
The adaptive cruise control is dependent on other systems in the vehicle. If any of these systems stop working the cruise control is turned off automatically. At automatic deactivation a signal sounds and message for Cruise Control Disengaged is shown in the display. Then the driver has to take action and adapt speed and distance to the vehicle in front.
An automatic deactivation may be due to:
- engine rpm is too low/high
- speed drops below 30 km/h (Not S60 (11-), V60 and XC60 (XC60 from structure week 201046) as well as from model year 2012 also S80 (07-), S80L, V70 (08-), and XC70 (08-) - all with automatic transmission)
- wheels lose traction
- brake temperature is high
- Forward Looking Radar (FLR) is covered by, e.g., wet snow or in case of heavy rain (radar waves blocked).
Note! To activate the adaptive cruise control the driver has to close the door, buckled the seatbelt, and then pressed at least once either on the accelerator pedal or the brake pedal. This is a way to ensure that the driver is in the car, before allowing activation.
Note! The driver always has to pay attention to traffic conditions and take action when the adaptive cruise control does not maintain suitable speed or suitable distance.
Note! The adaptive cruise control is not a collision-avoiding system. The driver must take action if the system does not detect a vehicle in front.