Driver's Responsibility
It is always the responsibility of the driver to ensure that there is a sufficient distance to the vehicle ahead and that the speed is adjusted to the current traffic conditions.
Closing velocity module (CVM) (4/125) communicates continuously with Brake control module (BCM) (4/16), Engine control module (ECM) (4/46), Climate control module (CCM) (not XC60 before structure week 201046), Climate control module (CCM) (not XC60 before structure week 201046), combination instrument (DIM) (5/1), and Supplemental restraint system module (SRS). Control modules receive information if there is a risk of collision with vehicles in front of your own vehicle.
The Closing velocity module is included in the support function and its main task is to prevent or minimize the affects of low speed collisions.
When the engine is started, the support function is always activated and it is active within the speed range of 4 - 30 km/h.
On S60 (11-), S80 (07-), S80L, V70 (08-), XC70, and V60 as well as XC60 from 201046, the driver can turn off the function during the existing driving cycle via the menu in Infotainment control module.
If the speed difference is 4-15 km/h related to the car ahead then can completely avoid a collision.
If the speed difference is 15-30 km/h between the vehicles, can not avoid collision on its own - for full brake force the driver has to press on the brake pedal and then it may be possible to avoid a collision even at differences above 15 km/h.
The Closing velocity module (CVM) can request different functions depending on the actual situation:
- Preloading the brake system
- automatic braking
- torque limiting in engine
- brake assistance EBA.
Preloading the brake system
For as fast a response as necessary when braking, the brake system's hydraulic pump activates at exactly the time the Closing velocity module (CVM) requests automatic braking of the vehicle.
When the hydraulic pump is activated, the brake pads move closer to the brake discs, which shortens the vehicle braking distance when braking.
Preloading the brake system does not affect the driver or passengers in the vehicle.
Automatic braking
Automatic braking is initiated by the Closing velocity module (CVM) when there is a risk of a collision with a vehicle ahead. The request for automatic braking is sent via the CAN network from the Closing velocity module (CVM) to the Brake control module (BCM).
Torque limiting in engine
During automatic braking, the engine torque is limited so as not to affect vehicle braking. The request for torque limiting is sent via the CAN network from the Closing velocity module (CVM) to the Engine control module (ECM) (4/46).
Emergency Brake Assistance (EBA)
During automatic braking, the parameter for the request for brake assistance EBA reduces. This means that the driver does not have to press as hard on the brake pedal in order for EBA to be activated.
Brake assistance, EBA, is activated by the Brake control module (BCM) by the hydraulic pump increasing the brake pressure in the brake system, so that optimal brake effect with the ABS function is achieved.