Such complexity brings with it reliability issues. IBM claims that approximately 50 percent of car warranty costs are now related to electronics and their embedded software, costing automakers in the United States around $350 and European automakers 250 per vehicle in 2005.
In 2005, Toyota voluntarily recalled 160 000 of its 2004 and some early 2005 model year Prius hybrids because of a software problem that caused the car to suddenly stall or shut down. The time needed to repair the software was estimated at about 90 minutes per vehicle, or about 240 000 person-hours. Even at cost, that is a lot of money.
Last year alone, there were several automotive recall notices related to software problems. For example, in May 2008, Chrysler recalled 24 535 of its 2006 Jeep Commanders because of a problem in the automatic-transmission software. Then in June, Volkswagen recalled about 4000 of its 2008 Passats and Passat Wagons and about 2500 Tiguans for a problem in the engine-control-module software that could cause an unexpected increase in engine revolutions per minute when the air-conditioning is turned on. In November, GM recalled 12 662 of its 2009 Cadillac CTS vehicles for a software problem within the passenger-sensing system that could disable the front passenger air bag when it should be enabled or enable it when it should be disabled. It is a tribute to the automotive software developers, though, that there aren’t many more recalls, given all the software in cars.
The increased use of software has not only affected car warranty costs but has also made cars harder to repair—so much so that insurance companies increasingly find it cheaper to declare cars damaged in accidents total losses than it is to fix them.
It is not hard to understand why. ”In a premium car you have 2000 to 3000 singular functions that are related to software,” Broy says. These are then combined into the 250 to 300 functions used by the driver and passengers to operate the car’s systems.
And unlike most commercial aircraft, which have strict firewalls between critical avionic systems and the in-flight entertainment systems, there is more commingling of information between the electronic systems used to operate the car and those for entertaining the driver and passengers. According to a Wharton Business School article entitled ”Car Trouble: Should We Recall the U.S. Auto Industry?,” a few years ago, some Mercedes drivers found that their seats moved if they pushed a certain button; the problem was that the button was supposed to operate the navigation system.