Ignition interlock devices are often placed on the vehicles of those who have been convicted of driving under the influence. The devices are installed in cars and require the driver to blow into it before the car will start. The ignition interlock device serves as a breathalyzer which the driver must pass before driving the vehicle.
If the driver blows a blood alcohol concentration under the limit set by the breathalyzer, the device will allow the vehicle to start. If the driver's breathalyzer test shows a result above the alcohol limit, the vehicle will be unable to start and the results will be stored on the device's memory bank.
However, these devices are causing some significant problems for auto shops. The devices are hard-wired into the on-board computer of the car. Mechanics are reporting concerns with these devices, as they would have to blow into the same mouthpiece to start vehicles' engines. Many mechanics and auto body workers say this is not a safe or healthy approach.
Further, servicing vehicles equipped with an ignition interlocking device can prove difficult. Many mechanics are concerned that they will cause trouble by tampering with the device, which is a tool ordered by a court. Some are even concerned that they might face liability for meddling with the device in the case it needed to be dismantled for diagnosis of the vehicle.
Apparently there are some other types of ignition interlock devices that do not cause these types of problems. They have a removable mouthpiece and reportedly do not interfere with diagnostics. Hopefully these types of devices are made readily available for those who are ordered to place an ignition interlock device on their car.
Source: Wivb.com "Can ignition interlocks pose risk?," Emily Lenihan, 5 November 2010