Electronic gas pedals... need some info if possible

[Brett Dikeman]

Gerard wrote:

> Just looking for info on these for a friend with a TDi. Mostly pin-out 
> information on the connectors and such stuff.

Pinout might be easily discovered.  If I remember the Bosch TBW paper I 
read a while ago, they're set up with two potentiometers as electrical 
opposites.  Sorta like this:

Position	A	B
idle			H	L
mid		M	M
full		L	H

(simplified.  The mid-position values almost certainly don't match.)

The ECU compares the two, and if they disagree, the ECU goes into 
limp-home model.  That way if one potentiometer goes wacky or there is a 
wiring problem, the ECU knows because the second's signal won't agree. 
Being electrical opposites provides further safety for potential shorts 
in wiring harnesses and the like.

It's possible some are digitally encoded with an optical encoder or a 
relatively new sensor (hall-effect based angle sensor) but both are 
pretty expensive- the hall effect angle sensor is probably at least 
$10-20 in high volume, where as two potentiometers are maybe a buck or 
two absolute tops.

I know a number of swaps have been done...TDIclub is probably the place 
to check for information about that kind of swap.

Brett

-- 
"They that give up essential liberty to obtain temporary
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