Was - Tac was bouncing around than died ( 93 100 csq 12v)- now ECU'S can't swim

Tom B dr_hydro at hotmail.com
Mon Jul 12 10:45:03 EDT 2004

Hi Edward,
Thanks for the reply. Shortly after I posted the original post I went for 
another drive and had several other  symptoms pop up. The car wasnt running 
right, no power and sometimes it would stall. The tac was working 
intermittantly, but when it was working was giving erroneous readings. Then 
the check engine light started flashing, instead of coming on and staying on 
like it normally does when the ECU detects a fault. Final symptom was the 
oil pressure warning coming up on the autocheck display, but the oil 
pressure gauge read normal pressure (5 bar).

All of these symptoms popping up in the space of 20 minutes led me to 
believe something, most likely the ECU,   had gotten wet during the 
torrential downpour we had the night before. I decided to see if there was a 
leak into the cabin that had gotten said something wet.  It turns out my 
sunroof had leaked and there was about an inch of water under the plastic 
covers located in the passenger side footwell.

This happens to be where the ECU is located, and the bottom of the ECU 
(where everything plugs in) was sitting in water.  I pulled the ECU out, 
took the covers off and let it dry out overnight. After vaccuming out the 
water in the floor pan  I replaced the ECU (now dry and in a protective 
plastic bag) and the car fired right up and ran normally, with all 
indicators / gauges performing flawlessly. A happy ending to a very 
disturbing incident. Now I just have to clean the drains for my 

Have a great day and thanks to all of you who answered for your suggestions,

>From: "Edward McCarthy" <ed.mccarthy at agilecommunications.com>
>To: "Tom B" <dr_hydro at hotmail.com>,<quattro at audifans.com>
>Subject: RE: Tac was bouncing around than died ( 93 100 csq 12v)
>Date: Mon, 12 Jul 2004 09:43:49 -0400
>Never had this problem on my Audi (so the following may be all wet and
>not apply), but have seen this behavior on other vehicles when an
>electrical ground has gone loose.  I hope this isn't the case for you,
>as finding the culprit connector can be a real pain in the a@#.  You may
>want to check for connectivity to ground from a few spots with your
>multimeter.  Since this problem can be intermittent, you may want to
>check, then drive car around block and check again....
>-----Original Message-----
>From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com]
>On Behalf Of Tom B
>Sent: Friday, July 09, 2004 3:22 PM
>To: quattro at audifans.com
>Subject: Tac was bouncing around than died ( 93 100 csq 12v)
>Hey all,
>My tachometer on my 93 100 csq (12 valve 6 cylinder) started bouncing
>around this morning and then finally quit giving any reading at all. Can
>someone inform me as to where the tac gets its signal on these cars? I'm
>hoping that there is an intermittant break in the wire, or an inproperly
>seated connector. Anyone have any other ideas?
>FREE pop-up blocking with the new MSN Toolbar - get it now!
>quattro mailing list
>quattro at audifans.com

Express yourself instantly with MSN Messenger! Download today - it's FREE! 

More information about the quattro mailing list