[TR] Off-topic -deadly floormats

[George Richardson]

An interesting note for those who might not be familiar, Volvo adopted a 
drive by wire system in 1999. The motor controlled throttle body was 
designed and supplied by Fiat. This has proven to be a major failure 
point in Volvos equipped with it. At least one fatality is said to be 
caused by it.

The failure can cause stalling, engine fault lights and surges in 
acceleration. There was an NHTSA recall for some cars to fix the 
problem, but the real issue is the throttle body uses cheap file 
potentiometers as feedback, and they start to wear and accumulate dirt 
quickly. I've actually done a tear down of one to look into the problem 
with an idea for a proper upgrade to hall effect (no contact magnetic) 
sensors designed specifically for the job.

You won't hear much about it of course, because Volvo is the "Safety car".

George Richardson



Dave1massey at cs.com wrote:
> In a message dated 9/18/2009 6:10:26 PM Central Daylight Time, 
> mkearns2 at gmail.com writes: 
>   
>> There was an article in the San Diego Union Tribune (a rag of a paper 
>> btw)
>> from  the head of some auto safety organization who insisted that the 
>> floor
>> mats were not the real cause.  According to him the ignition systems have
>> become so complex that electromagnetic interference can cause these types 
>> of
>> occurrences.  Since that article came out there have been many accounts 
>> from
>> people reporting unexplained short term bursts of acceleration.
>>
>>     
> Typical non-technical jounalist, me thinks.  EMI causing havoc in the 
> ignition system would only cause the engine to misfire and reduce power.
>
> However, IF that car has "Drive-By-Wire,' or a servo actuated throttle, EMI 
> could certainly cause the throttle to open without respect to the command 
> coming from the gas pedal.
>
> Does this car have Drive-By-Wire?
>
> Dave
> _______________________________________________
>
> Support Team.Net  http://www.team.net/donate.html
>
> This list supported in part by the Vintage Triumph Register
> http://www.vtr.org
>
>
> Triumphs at autox.team.net
> http://autox.team.net/mailman/listinfo/triumphs
>
>
> http://www.team.net/archive
>
> __________ Information from ESET Smart Security, version of virus signature database 4441 (20090919) __________
>
> The message was checked by ESET Smart Security.
>
> http://www.eset.com
>
>
>
>
>   


__________ Information from ESET Smart Security, version of virus signature database 4441 (20090919) __________

The message was checked by ESET Smart Security.

http://www.eset.com