Revenge of the Nerd: Bravo Toyota!

Drive by wire throttle body

Revenge of the Nerd: Bravo Toyota!

By Mike Kojima

Today Toyota announced perhaps what is the most extensive, comprehensive and expensive recall in the history of Automotive manufacturing.  The recall involves eight of their best selling models from the Camry to even our Project Tundra.  2.3 MILLION vehicles will be affected by this recall. In an unprecedented move, Toyota has also stopped all sales and production of the potentially affected models as well. This affects more than 100,000 brand new Toyotas in the sales pipe line.  This is STOPPED, dead cold, with thousands of workers at plants and dealerships who as of next Monday will be sitting around twiddling their thumbs. This recall will probably be disastrous financially for Toyota.

The recall is about drive by wire throttle control systems that may potentially stick.  Drive by wire throttles are throttles that are controlled entirely by the engines ECU with no physical linkage between the gas pedal and the engines throttle blades.  Don't worry, this is not weird radical stuff, nearly all cars are drive by wire nowadays. The recall is the result of an extensive investigation of warranty data that was launched after a tragic accident this summer when a sticking throttle caused a terrifying accident where a Lexus ES350 ran out of control at high speeds.  The Lexus ran away, stuck on full throttle with failed brakes on a San Diego freeway for several minutes before it crashed, killing an experienced Highway Patrol officer and his entire family.

When you look at the data, the occurrence rate of Toyota drive by wire throttle malfunctioning is pretty low, although it is higher than some other manufactures. Some of these issues are probably due to the software logic of the Toyota drive by wire throttle system which allows the throttle to function under driver control when the brakes are simultaneously applied.  Some manufactures like Nissan have a failsafe that cuts the throttle when the brakes are on.  I have personally criticized Nissan for this because as a performance driver, I often do things like left foot brake to help rotate a car or balance an understeering chassis.  Off road guys often left foot brake to help stop a differential from spinning out of control, losing traction, or to rock a car stuck in sand, mud or snow.  The failsafe precludes you from doing these things.  It also stops you from doing burnouts.

Perhaps a dumb thing on Toyota's part is for their smart key systems off switch, you have to hold the start button down for 3 seconds when the transmission is in drive before the ignition is actually killed.  3 seconds is an eternity when you are trying to control and stop a run away car and is not intuitive even if you are familiar with the car.  I think this is what probably helped kill the Highway Patrol officer, heck; I might not figure that one out in a similar situation.

What I can't figure out is how a professional high performance driver, that is trained in emergency car handling allowed himself to die in this way.  In my years as an automotive engineer and a racer, I have actually attended several law enforcement agency advanced drivers training classes and although they were somewhat easy, they are way harder than what a typical drivers training class teaches you.  Remember readers, if your Toyota or any car for that matter sticks it's throttle, the easiest thing for you to do is to stick it in neutral!  Then figure out how to turn off your engine.  Modern cars have rev limiters so you are not going to blow anything up and just remember when you kill your engine, if you are still moving, your power brakes and steering are not going to work, so be ready for hard braking and stiff high effort steering. 

I have personally suffered from stuck throttles twice in my life.  The first time was in an RX-7 where the floor mat jammed the throttle.  I simply turned the key off and pulled over.  The second time was in a friend's Celica with dual Mikuni carbs.  My friend had put the linkage in wrong and the throttle stuck when I was testing it for him.  This time I pushed in the clutch because I had trouble reaching the ignition switch quickly (his car was pretty fast!).  The engine overreved and bent a few valves before I could reach the switch.  The lesson here was although in both cases this was bad, I reacted correctly and immediately without hesitation and was not even scared. Both of these cases where when I was young and before my training as well! Knowing this, I wonder what that Highway Patrol officer was thinking.  It's so sad that his whole family had to die because he apparently panicked.  According to 911 records (his wife actually called 911 asking for help!) the whole incident lasted several minutes, plenty of time to figure out to shift it into neutral!  The scope of this tragedy also rests largely on driver error.

drive by wire throttle

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