[s-cars] 034 HO Coil w/ AAN ECU?

Thu Dec 3 08:47:35 PST 2009

Guys-
For more on the ignition driver chip failures - check out this Motorgeek
thread:

http://www.motorgeek.com/phpBB2/viewtopic.php?t=31328#378226&sid=648b484f5f2
f715a1b77ec6e3246f719

Maybe it will clear some things up...then again maybe not.

Brandon

-----Original Message-----
From: JC [mailto:jc at j2c3.com] 
Sent: Wednesday, December 02, 2009 4:51 PM
To: 'Mike Sylvester'; 'Brandon Rogers'
Cc: 'Manuel Sanchez'; s-car-list at audifans.com
Subject: RE: [s-cars] 034 HO Coil w/ AAN ECU?

Just to chime in here, completely agree with Mike on comments about ignition
coils and "chip failures".  As an incompetent part-time puttering
electronics dork, I have a real hard time seeing how downstream coils could
cause EPROM failures.  Sure if the new coil drivers (whatever they use to
replace the OEM darlingtons aka "POS" - in Americun car terms 'exciters')
drew too much current vs. stock or if there was some flyback phenomena off
the coils or something I could see components in the ECU having trouble, but
it'd be a real long shot, and even then rather than damage an EPROM it'd be
more likely to be a driver transistor/IC or related passive component on the
output circuit of the ECU.  And it does seem like lots of folks have this
setup without trouble.

Having wasted way too much time trying to fix old electronics screwing
around with aged circuits, I would suggest a couple of other
possibilities... If what is happening is that the car develops problems and
replacing the EPROM chip solves it for a while, but it eventually recurs, it
easily could be a bad solder joint or pin connection that gets 'reset' when
the work is done but eventually fails again when the ECU is put back in over
time (with heat a good candidate for contributing factor).   So Brandon
while you say "FACT"... don't rule out a tricky mis-leading symptom. Happens
all the time with old electronics crap that you find replacing one thing
gives a temporary fix but reverts to the failure because it's not actually
the root problem... I had a Luxman integrated amp on the bench a while ago
that seemed to have failed output driver transistors.  Put a new one in and
everything seemed fine, couldn't measure a problem in the unit, but
eventually it would blow. Turned out it was failed solder joints with
micro-cracks not visible to the eye way far away somewhere else on the unit.
The way to confirm in this case would be to have an EPROM reader to truly
test the chip - if that's what your friend has done then I can fully accept
the fact of 'chip failures' but if its just that swappin EPROM chips makes
the problem go away for a while there is every chance that it is in fact
something else.

If it is indeed the EPROMS are failing, then I would say 99% it must be in
the ECU that is frying the EPROM. Has your guy swapped ECU's and had the
same problem with other ECU's?

BTW, is there a schematic for the AAN ECU anyplace? I'm sure the aftermarket
vendors have all either hand-mapped or purchased it from Bosch but I'd love
to peruse one just for stupidity's sake...

>
> By ignition chip, do you mean the eprom that gets replaced in an 
> upgrade? I would find that very surprising that an aftermarket coil
> could cause the ignition eprom to go bad.
> That chip is not driving anything external to the ECU.
> It just contains the map.
>
> WRT to the 034 coil solution, I have had these for a few years. You 
> can find some installation photos on my site. 
> http://www.urq20v.com/My_other_cars/S6/S6_repair.htm
>
> I also went with the 1.8 coils at first and replaced 2 in 2 weeks. I 
> now believe that the coil failures are due to bad plugs.
>
> I had to have the HO coils replaced after about 10k miles.
> It seemed like something corrosive leaked out of the coil into the 
> connector and melted them away. It was bad on one and starting on 
> another.  034 replaced them all.  It has been another 40k without an 
> issue.
>
> I don't know if he has changed the plug wires that he ships, but the 
> ones I got, were too long to re-install the center part of the cover.
> I have since reworked some 3B wires and machined the inside
> of my cover so that it fits properly.
>
> If you are going to use these on your 3B, the you can swap the ends 
> from the 034 wires onto yours so that they fit the coils.
>
> All in all they are working for me, but I have to think there is a 
> cheaper solution out there now.
>
> Mike
>
> www.urq20v.com
>
> > -------- Original Message --------
> > Subject: Re: [s-cars] 034 HO Coil w/ AAN ECU?
> > From: "Brandon Rogers" <brogers at terrix.com>
> > Date: Wed, December 02, 2009 12:06 pm
> > To: "'Manuel Sanchez'" <manuelsanchez at starpower.net>, 
> > <s-car-list at audifans.com>
> >
> >
> > I don't know the details - but do know the failures I was
> told about
> > do _not_ have to do with being "chipped" - but the way I
> understand it
> > is some AAN ECUs are failing - and it is the ignition chip
> within the
> > ECU - he _thinks_ it _might_ be due to aftermarket coil systems. 
> > Again - just his theory.  That's why I'm curious about
> people's direct
> > experience with this particular coil setup (034) - as I
> have one I plan to use...
> >
> > So far people here seem to have had good experiences....
> >
> > So to reiterate:
> >
> > Facts:
> > There have been ignition chip failures in some AAN ECUs
> >
> > Theory:
> > Might be due to aftermarket ignition (coils) - didn't say
> what kind -
> > don't know if he even knows...
> >
> > Brandon
> > '84 urquattro 20Vt
> > '01 S4
> >
> > -----Original Message-----
> > From: Manuel Sanchez [mailto:manuelsanchez at starpower.net]
> > Sent: Wednesday, December 02, 2009 6:26 AM
> > To: s-car-list at audifans.com
> > Cc: brogers at terrix.com
> > Subject: [s-cars] 034 HO Coil w/ AAN ECU?
> >
> >
> > Brandon,
> >
> > I've had the 034 HO coils on my RS2'd car for a couple of
> years now as well.
> >
> > I had some initial "teething" problems that in the end
> turned out to
> > be a bad ignition wire (it had a knick in it). Once that was chased 
> > down it has been trouble free (knocks on wood).
> >
> > My OE setup failed about 15,000 miles ago, so I obviously can't 
> > compare the longevity question with regard to the OE vs 034 systems.
> >
> > I must admit however that in the dark days on trying to chase down 
> > what the problem was with the new system I told myself that
> I should
> > have just bought the more expensive OE Coils and OE POS's,
> after all,
> > they lasted 100,000 miles.
> >
> > Having said that. the 034 HO system is very simple to
> install, and the
> > new ignition wire boots are of a different length that
> allows you to
> > place the coil pack cover overtop them spark plug wells so
> you can keep the crud out.
> >
> >
> > I am curious though about these ECU chip failures you write
> about. Can
> > you expand a bit more on what the theory or evidence has been? What 
> > aftermarket systems have "caused" or been thought to cause the Chip 
> > failures? Why does this person surmise that the coils have
> caused an ECU problem.
> >
> > Regards,
> >
> > Manny
> >
> > 95.5 ur S6 Avant (mostly RS2'd)
> >
> >
> > On Dec 1, 2009, at 10:04 PM, s-car-list-request at audifans.com wrote:
> >
> >
> > ------------------------------
> >
> >
> >
> >
> > Message: 2
> >
> > Date: Tue, 1 Dec 2009 14:53:55 -0700
> >
> > From: "Brandon Rogers" <brogers at terrix.com>
> >
> > Subject: [s-cars] 034 HO Coil w/ AAN ECU?
> >
> > To: <s-car-list at audifans.com>
> >
> > Message-ID: <636621FF56584C19A95437D476CAA475 at BCROGERS>
> >
> > Content-Type: text/plain; charset="us-ascii"
> >
> >
> >
> >
> > Guys-
> >
> > Curious what people know about using the 034 HO Coils with the AAN 
> > ECU.  Are
> >
> > many guys here using the 034 HO Coils?  (Or mostly 1.8T
> coils (I don't
> > want
> >
> > to do the 1.8T coils)).  Do you guys know of people having
> any issues?
> >
> > Reason I ask is because I know somebody who is seeing a
> fair number is
> >
> > ignition chip failures within the AAN ECUs and he thinks
> they MIGHT be
> >
> > related to aftermarket ignition (coils).
> >
> >
> >
> >
> > Any BTDT?
> >
> >
> >
> >
> > Brandon
> >
> > '84 ur-quattro 20Vt - going COP
> >
> > '01 S4
> >
> >
> >
> >
> >
> >
> >
> >
> > _______________________________________________
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