System Overview: General

Courtesy of VOLVO CARS CORPORATION

The system for the automatic starting/stopping of the engine is a function that saves energy, with the aim of reducing fuel consumption, which in turn contributes to a reduction in exhaust emissions. The function stops the engine automatically when the vehicle stops during driving; shift the gear lever to neutral and release. The system is designed for use in, for example, traffic jams or at traffic lights. The engine then stops in autostop (wait mode) and the restarts when the clutch pedal is depressed again (autostart). Then simply engage a gear and continue the journey.

On vehicles with automatic transmissions, the engine is stopped when the brake is pressed down and restarted again when the brake is released.

All the ordinary systems of the car, such as lighting, radio etc. work as usual during autostop with the exception that some equipment may have reduced functionality, temporarily. E.G. the climate control system's fan or sound system's volume. See: DESIGN .

Courtesy of VOLVO CARS CORPORATION

The on/off button positioned in the tunnel console indicates that the vehicle has the automatic start/stop of the engine function. The button symbol differs for different model years. (Vehicles equipped with ECO Cruise can have DRIVe button without start/stop). The system activates automatically when the engine is started by key. The driver notices this as the on/off button's green diode illuminates. In some situations it may be necessary to temporarily disengage the automatic engine start/stop function, this is done via the on/off button. The automatic engine start/stop function is off until it is reactivated using the button or until the next time the engine is started using the key.

In some circumstances, text messages appear on the information display. The text messages indicate whether the function is engaged or not, give driver assistance in certain situations and indicate any function errors. For more information, see the Owner's Manual.

The automatic start/stop of the engine function is a distributed system that to some extent is monitored by the component control modules. A number of modules and components are mixed for the different functions:

• Engine Control Module (ECM).
• Central Electronic Module (CEM)
• Driver Information Module (DIM)
• Brake Control Module (BCM)
• Infotainment Control Module (ICM) or Infotainment Head Unit (IHU)
• Climate Control Module (CCM)
• Supplemental Restraint System Module (SRS)
• Combustion Preheater Module (CPM)
• Power steering control module (PSCM)
• Steering Wheel Angle Sensor Module (SAS)
• Trailer Module (TRM)
• Park Brake Module (PBM)

The Engine Control Module (ECM) and Central Electronic Module (CEM) contain the main parts of the functionality.

The system also contains the following components:

• Battery (main battery) with battery relay (main battery)
• Secondary battery with secondary battery relay
• Starter motor
• The main battery fuse box with fuses and battery diode
• Battery Monitoring Sensor (BMS)
• Electric oil pump (EOP)
• Electric parking brake (EPB)

The system has two batteries: a battery (main battery) and a secondary battery. For normal key starts only the battery (main battery) is used. The battery manages the entire power supply of the vehicle during the entire time except during autostart. During autostart the electrical system reconnects via two relays so that the secondary battery takes over the power supply to all the power consumers of the vehicle except the starter motor.

The system for automatic start/stop of the engine is operational in certain conditions. See: Function.

The Engine Control Module (ECM) and Central Electronic Module (CEM) detect and store information about which causes can block the automatic start/stop of the engine function and which causes can cause the system to request autostart in autostop mode from the respective system area. These causes are collated under VIDA - DIAGNOSTICS/VEHICLE COMMUNICATION/ECM/Advanced