Our Computerized Cars: They're Scary at 70 MPH

Last Updated Feb 24, 2010 1:00 PM EST

If there's one thing we've learned from the Toyota fiasco, it's that modern cars are far more like computers than most of us realized. There are an estimated 30 to 50 Electronic Control Units (ECUs) in a typical car (more in luxury vehicles), and something like 10 million lines of software code. Frost & Sullivan business researchers estimate that could soon grow exponentially--to as much as 300 million lines.

Most of us know by now that Toyota--and just about every other carmaker--uses "throttle by wire" technology, meaning that software controls the car's acceleration, not your right foot. But there's also steering by wire, braking by wire and many other systems. Most of us have never given a thought to the computer systems that make up as much as 40 percent of a car's costs, but the Toyota hearings, painfully underway on Capitol Hill, have brought the subject into stark relief.

Is the federal auto watchdog agency, the National Highway Traffic Safety Administration (NHTSA), up to the task of overseeing these servers on wheels? That's an important question, because Transportation Secretary Ray LaHood (who supervises NHTSA) said in testimony yesterday that the agency had thoroughly investigated electronic interference as a cause of runaway Toyotas, and so far come up dry (a "review" is underway).

There seems to be some disagreement over how many electrical engineers the agency employs. The Washington Post first reported the number yesterday at zero, but the Detroit News then quoted the agency's Olivia Adair: "NHTSA has numerous engineers on staff with experience with electrical engineering and [electronics] issues," she said. But LaHood also told House investigators that there are just two on staff, and outside help is called in when needed. A call to NHTSA's Adair for clarity was not returned.

Coincidentally, NHTSA's defects division has hired a public relations firm, Edelman, which asked me yesterday if I wanted to "partner" with it. If we're going to be partners, we'll have to be quicker about returning phone calls.

As someone who's had his share of computer glitches, the fact that my car is run by bytes and bits (or is that zeroes and ones?) is not necessarily comforting. But Farhad Manjoo writes in Slate that "thousands of individual functions" on the car are now computer powered is a good thing.

"Software controls the mechanism that lets you unlock your doors, adjust your seats, and start the ignition," Manjoo writes. "There's software in the powertrain--electronic components fire the sparks, determine the correct transmission gears, and constantly adjust subtle driving characteristics to optimize fuel economy." How high tech. But computers also get blue screens, and so too do Toyotas--but they may be moving down the highway at the time.

Integrating computers into cars is mostly a good thing, says Manjoo, because "the beauty of software is that it can be updated from afar--Through software patches, [cars will] keep getting better fuel economy and better safety systems. When something goes wrong, they'll be easier to fix."

Argghh. That is totally not borne out by the Toyota experience. The company has been fielding sudden acceleration complaints for almost 10 years, and according to House committee chairman Henry Waxman yesterday, have never thoroughly investigated possible electronic causes.

Toyota North American chief Jim Lentz testified yesterday that, after repeatedly denying electronic causes, the company is now admitting the possibility of "mechanical, human or some other type of error." In other words, they're conceding that sticky pedals and floormats don't explain all the cases.

Part of the problem is the complexity of all that computer code: Expert testimony before the House yesterday revealed that, in some circumstances, problems could occur that would not set off a diagnostic trouble code--making it very hard to trace. At least Windows tells you when it's "experienced a serious error." According to David Gilbert, a technical educator at Southern Illinois University, "My initial findings question the integrity and consistency of Toyota Electronic Control Modules (ECM) to detect potential electronic throttle control system circuit malfunction."

The electronic genie is out of the bottle. Cars aren't going back to the purely mechanical state of my 1963 Dodge Dart convertible, with nary one line of computer code. But my Dart doesn't have a sudden acceleration problem, either.