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Home >> Volvo >> 2009 >> V70 >> Repair and Diagnosis >> Engine Performance >> Engine Control Systems >> Charging System, Electrical Control Modules, Engine Control Module (ECM) - Design And Function >> Forward Sensing Module (FSM) (2009-10) >> Function >> Controlling The Adaptive Cruise Control
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Controlling The Adaptive Cruise Control

Fig 1: Identifying Adaptive Cruise Control
GLL170518Courtesy of VOLVO CARS CORPORATION

The function adaptive cruise control is an extension of the existing cruise control. If there is no vehicle ahead, the speed will remain unchanged as for conventional cruise control. Speed is set by the driver in a similar way as for 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 gap to the vehicle ahead is set by the driver in five steps, in the interval 1 to 3 seconds. If no earlier setting has been made, then step 3 of 5 will be used as basic value.

When the system is activated, the last selected interval 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).

The function adaptive cruise control is limited to a speed that is higher than approx. 30 km/h.