Tuesday, March 09, 2010

I hadn't been following the Toyota recalls very closely,

then Insty pointed to this at Popular Mechanics. It appears that professor of automotive technology Dave Gilbert, of Southern Illinois University's auto technology department, went ahead and modified a new Avalon to go to full throttle with the flip of a switch, by altering the same circuits I wrote about. Gilbert appeared on ABC news and testified before Congress that his manipulations demonstrate how easy it is for Toyotas to accelerate out of control. And there's more: He suggested that his analysis shows how all electronic throttles are inherently dangerous, because Toyota's throttle-pedal electronic architecture is similar to that used by almost every car manufacturer.
Which sounds pretty bad. Except:
Here's what Gilbert had to do to make his Avalon go rogue: He had to cut open three of the six wires that travel from the pedal assembly to the engine computer. Two of the wires send the accelerator-position signals—one for each Hall-effect sensor—and one is a 5-volt power supply. Next he had to insert a specific 200-ohm resistor between the two signal wires. Finally, he had to generate a direct short between the 5-volt supply lines and the signal leads. The new wiring essentially mimicked a size-12 mashing of the pedal to the carpet and the engine went to WOT. Also, the order of the modification is important. Apply the 5-volt power lead to the wires before inserting the resistor and the computer would instead throw a fault code and go into limp mode.
So you're talking about some fairly interesting surgery to get this to happen, not exactly a "Your cell phone/radio/overhead power lines/water leak can cause this" thing. And a very good question follows:
One pertinent factoid: Not a single case of sudden unintended acceleration (SUA) has been attributed to bad wiring. None. Toyota has been harvesting parts from vehicles with documented SUA issues as part of the recall, and they're checking them all. None of them have shown any sign of corrosion or shorted wiring. Toyota also illustrated that Gilbert's modification works on cars from many different manufacturers. During a webcast explaining the modifications, Toyota had a half-dozen cars built by a half-dozen companies that were rewired in the same manner. All of them produced the same result as that Avalon. The question is: What would make an engineering professor stick his neck out so far?


Keith said...

I don't know of any road legal car that doesn't have far more powerful brakes than it does engine.

Step on the brake and it will stop that engine regardless.

Now why would he stick his neck out? - very good question.

Anonymous said...

Why would thirty DEMOCRAT representatives all of whom have gotten large contributions from the UAW be (attacking) conducting hearings on Toyota, who makes cars in Georgia, a right to work state? And which company pays its workers very well indeed?

The obvious answer is insufficient opportunity for democrat graft.

I'm coming to the conclusion that elected democrats should be dragged into the public square and flogged. All of them.

Gerry N.