Posted 08 February 2010 - 10:25 PM
Kind of amazed no one has brought this up yet so I will.
Heres the summary of what has occurred so far:
1) In mid 2009 Toyota recalled 8 Toyota and Lexus (Toyota's North American luxury brand) models for "improper Floor mats causing the Accelerator pedal to become stuck"
2) In late 2009 Toyota stated that the floormat were not to blame for all the "sticking accelerator pedal" issues and reworked the pedal design to include a heavier return spring. Again 8 models were recalled and a stop on selling and production of the afflicted models.
3) Last week Steve Wozniak (aka The Woz, co-founder of Apple Computer) made comments about Cruise Control and braking issues in his 2010 Prius. Toyota is now investigating the regenerative Braking system on all hybrid models.
Here's what I know of the Vehicles involved:
1) All use a "drive by wire" Accelerator pedal
2) The Regenerative braking system is also "drive by wire" but has a manual Hydraulic brake backup (unlike most cars there is no Brake Booster so you must push very hard on the pedal to make it stop)
Drive by wire is a term used to refer to vehicle controls (steering, braking, throttle) that are controlled by electronics instead of the traditional cables and hoses.
I deal with Drive by wire accelerators vehicles at work every day, how Toyota makes theirs may be differant, but if there is a flaw in the pedal circuitry you will have no Acceleration at all (they will no move above idle). the pedal electronics are fairly simple with a rheostat that as you push down on the pedal decreases circuit resistance and increases voltage (as per Ohms law) and a heavy spring to push the pedal back up and give the driver "feel" . Cruise Control pretty much "fakes" the pedal signal to make the ECU (Engine Control Unit) believe that the accel is pressed down so far in most cases (some manufacturers use other means but this is the most common). Most drive by wire pedals work the same way (every vehicle I've dealt with has, Chevy, ford, dodge, big trucks are all the same). So in my opinion the pedal isn't wholly to blame.
Hybrids and regenerative braking systems i do not grasp nearly as well (as i don't have to deal with them), but given the fact that most of these cars are using similar computers and programming it seems possible that there could be a software/hardware issue which needs to be looked into. Whats your take?
Finally Words of advise if you ever have a stuck Accelerator pedal (any vehicle). In this order 1) Shift into Neutral. 2) Bring the Car to a controlled stop. 3) Shut off engine. 4) Check your pedal for obstruction, if none is found have it towed to the nearest shop.