Alcoguard isa fully integrated in-car breathalyser that utilises advanced fuel-cell technology.
Before the car can be started, the driver has to blow into the wireless hand-held unit. This unit is the size of a small remote control and it is stored and charged in a compartment behind the centre console.
The driver's breath is analysed in the hand-held unit which then transmits the results via radio signal to the car's electronic control system. If the blood-alcohol limit of 0.2 g/l is exceeded, the engine will not start.
Thanks to advanced sensors, it is not possible to use external air sources such as a pump to cheat the system.
The results of the breathalyser test are shown via three LEDs in the hand-held unit.
The car's information display shows messages to help the driver in the system's usage, for instance to indicate if the test was approved or if the driver needs to exhale longer into the hand-held unit.
The breathalyser results are stored for 30 minutes after the engine has been turned off, so the driver does not need to repeat the procedure every time he stops for a short while. The preset limit of 0.2 g/l has been chosen to meet Swedish legislation.
On markets with other limits, the Volvo workshop can alter the setting.
The hand-held unit is wireless, which makes it possible for the driver to remove it from the car. Although it will always give an accurate measurement of blood-alcohol level no matter where it is used, it is only if it is within ten metres of the car itself that the hand-held unit can communicate with the vehicle.
Volvo says that Alcoguard should be seen as a supporting system.
For emergency situations or if the hand-held unit is lost, there is a bypass function that can be activated.