[A4] Coil Pack Help

Brandon Rogers brogers at terrix.com
Wed Jul 6 11:25:11 EDT 2005

Here's my experience from just a couple weeks ago:

For the past several months while idling at a stop light the car seemed to 
miss occasionally - but never experienced drivability issues.  Until one day 
I started the car up after lunch and it was real rough.  Restarted the car - 
no change.  Decided to limp it to the office - engine was rough and 
shuddered under any boost - really only seemed OK at about 3000-4000rpm in 
second.  Anyway I pulled the plugs that night - one was clearly darker than 
the rest - it wasn't firing.  I had a known good and installed - no change. 
So at this point I think you need a PRO-DIAG or VAG COM - I pulled codes and 
got Misfire Cyl # 2 (apparently #2 is the common ICM failure, I think) - so 
I cleared codes and swapped the coilpacks and restarted the motor and let it 
run for a while - and revved it a few times.  Re-pulled codes - still Cyl 
#2.  Clearly not a coil pack issue (otherwise the misfire would have moved 
with the transfer of the coil pack).  Bingo ICM.  I got an aftermarket Huco 
part  - retail price was about $250 at a local import parts place - maybe 
try Rod at www.thepartsconnection.com for best price. ( I hear the dealer 
wants $400 for Bosch - but I didn't verify).  And don't forget to apply some 
new Silicon or dielectric paste under the new part.  Does you car have one - 
I bet it does.  On my '98 it's right under the cover over the airbox - two 
plug little piece.  I don't know how you could diagnose this without some 
diagnostic tool such as Pro-Diag or vagcom.  It sounds like you may have one 
of these, luckily.  BTW Pro-Diag tells you what the fault is - no looking up 


'98 A4
'84 urquattro 20V

----- Original Message ----- 
From: "Mitchell Segal" <MSegal at nsbgroup.com>
To: <a4 at audifans.com>
Sent: Wednesday, July 06, 2005 7:23 AM
Subject: Re: [A4] Coil Pack Help

> Hellow everyone,
> I've been following this discussion about coil packs, and now someone
> mentioned the ICM as a possible cause to their problems.  I was wondering 
> if
> someone can tell me how to test the ICM, to see if it's the cause of my
> problem.
> I have a 2001.5 1.8TQ, and I have an occasional stumbling/stalling/loss of
> power.  It's not constant, which is the biggest problem, because it never
> happens when you're at the dealer to show them.  Shows up most after the 
> hot
> car has sat for 30-60, and you restart it (heat-soak problem maybe?)
> Happens most often around 2000 rpm.  Will feel like a total loss of power,
> even with pedal to the floor, for 1-2 sec, and then it recovers.  I have 
> the
> replaced ignition coils, and dealer has changed the throttlebody.  I get
> random misfires all over the place, never the same cylinder.  I pulled 5-6
> fault codes off this past weekend, but I haven't had time to look them up
> yet (is the list in the shop manual?  Is there an online list somewhere?)
> Something has been telling me that this is an electrical problem, like a
> sensor that's starting to go bad, and send false signals which is 
> confusing
> the computer.  But now that you mention this ignition control module 
> (ICM),
> perhaps I should start looking there.  I have shop manuals at home, I'll
> check them out tonight, but does anyone know if there's any kind of test 
> to
> tell if the ICM is good or not?
> Does anyone know if my car even has this ICM, and are they a known problem
> in my model year?  Lastly, if it is the ICM, is there a jobber part that's
> better, or just stick with the Audi/Bosch version, and be prepared to 
> change
> it every few years?
> Thanks a lot for any help you can give me with this problem.  I've been
> living with it on and off for 3 months now, and it's starting to drive me
> crazy.
> Mitchell
> ------------------------------
> Date: Fri, 24 Jun 2005 14:46:43 -0600
> From: "Brandon Rogers" <brogers at terrix.com>
> Subject: Re: [A4] Coil Pack Help
> To: <A4 at audifans.com>
> quick follow up
> installed Ignition Control Module last night - takes about 2 minutes - the
> car is running perfect again.
> Thanks to Pbadore for pointing me towards the ICM vs what I was thinking -
> (the coil packs).  And I must say the Pro-Diag from Shadetree was very
> helpful too.
> Brandon
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