when did vw/Audi go to the "drive-by-wire" instead of the

[Ti Kan]

JordanVw at aol.com writes:
> oh..and in addition to my question of WHEN did they change,  WHY did they 
> change over to drive-by-wire anyway????   what are the benefits?  it seems like 
> response is decreased with the electronic throttle vs the old cable type, which 
> was instantaneous..

There are many benefits of drive-by-wire.  For example, cruise control
and idle stabilization and full throttle enrichment no longer need
additional devices or switches, it can all be done from the ECU's software
directly.  The rate of throttle closing can also be programmed without
the use of hacks like dashpots, etc., less mechanical devices means
better reliability (say bye bye to having to clean your ISVs, or repair
bad throtle switches, or replace cruise control servos, etc., because
these all no longer exist).  Furthermore, with the advent of ASR, ESP
and other electronic assists, the ECU must be able to control the throttle.
This can only be done with drive-by-wire.  Also, the ECU can learn your
driving habits and optimize operating conditions (such as making
auto transmission shift points adapt to your style and make shifts
feel smoother by making throttle adjustments).  On DSG gearbox cars,
the ECU will blip the throttle for you to match engine RPMs for quick
shifting, and on multitronic (CVT) cars the drive-by-wire will optimize
acceleration *and* economy by choosing the best engine RPM and
transmission ratio for the conditions. etc., etc.

Drive-by-wire began around the 2000 model year on the A4, I think.

-Ti
2003 A4 1.8T multitronic
2001 S4 biturbo 6-sp
1984 5000S turbo
1980 4000 2.0 5-sp
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