About the "sudden uncontrolled acceleration" problem.

Comments? Suggestions? Ideas?


Please, NO FLAMEWARS.

http://www.phoenixnewtimes.com/2009-...dly-wild-ride/


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Please, Think before you post.

 

Interesting article. The article references (towards the end of it) about the need to ensure the driver's side floor mat is secured with the hooks.

I can speak from an experience that my wife had with our Mazda Tribute that the floor mats of a vehicle can slide forward. This causes the edge of the mat to press down on the accelerator pedal, causing an uncontrolled acceleration. Most vehicles these days have an accelerator pedal that is anchored from a pivot point under the dash, so a mat pressing on it can exert great leverage. (Not like in the old days where the pivot point for the gas pedal was on the floorboard).

Anyway, a couple of years ago, while on I-10 in San Antonio, she experienced uncontrolled acceleration. Even pressing fully down on the brakes did not good. She finally stopped it by turning off the engine. We had the vehicle checked out - brakes were fine; accelerator was fine. Later we discovered the mat was loose and by just getting in / out of the vehicle was enough to push it towards the accelerator. Thus, we think that was the cause. The vehicle had been washed a few days earlier and the mats were removed to clean them...and not locked down after the job was done.

Moral of the story -- check those mats on all cars and be sure they are locked down...

 

Given the nature of the control system, it could be a number of components failing that could provide that sort of behavior. Since the car is entirely a throttle-by-wire, any wackiness to the computer inputs (like the accelerator pedal pot going wonky or wire shorting) could all provoke ICE going to WOT - the computer is detecting a WOT requests when the pedal input tells it that's what's being requested. Unless you're really careful, this sort of problem could be really tough to trace. Also given the blended nature of the braking system, I would also expect the pedal inputs to be less than effective if the brake controller is detecting wonky signals.

IAC, the ECU tracks the last n seconds of operation - the data is available and waiting for analysis.