Jan 2005 CEL: 1999 A6 Avant 30V


CEL (Check Engine Light) scan and then rough running....

Subject: 1999 Audi A6 Avant 2.8 30V Tiptronic

I used the "Hex-Com" adapter and located the

diagnostic port under the dash knee pad


next to the hood release lever looking up from the floor.

With the car off*, I knew something was right when the

adapter lit up yellow then turned green.....

The CEL light was on in the Avant.

So I pulled out the Lap top and the cables to check it out.

Auto Scan, and chassis type I incorrectly selected so

I stopped this scan,  although the same DTC's came up.

Now the CEL came on RIGHT after the Audi recall campaign:  JB

Which was to fix the throttle body for cold winter freezing resistance.

2 Faults Fuel Trim bank 1 & 2 System too rich.

This code Vag-Com talks about.  Means nothing.

Here the Bose Radio lights up during its group check by Vag-Com.

Some cars display "Diagnostics"...

Address 35 Central Locking has trigger alarms.  Cleared them.

At this point the car door had been open awhile and the lights

on so I started the car to recharge the 3-4 year old battery.

So with it running, I again scanned the car

then went to reset the engine (address 1) DTC.

When I pressed clear codes the engine immediately QUIT.

(The above picture is a file photo)

Oh no......  As soon as I restarted the car it ran rough.

No CEL came on but the immediate scan produced these DTC's:

Again I cleared these codes and took the car for a spin.

I noticed hesitation from the low idle (transmission torque converter lag IMHO)

The car accelerated well and the only hint was the rough idle.

Over the next 25 miles the idle was a bit less rough.

as of now I'm still looking into this.


Anyone know why the clear codes on  channel 01 (engine) would kill the motor?

and are there any know problems associated with that?

-Thanks in advance

-Scott by BOSTON

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Glossary and footnotes:

DTC: Diagnostic Trouble Code?

* Off:  No key in ignition, just the door open.

** picture:  In windows 95, the drivers screen shows ports, accessories, hard drives etc..

might be under the heading of "hard ware profiles"

*** Dash IC:  IC = Instrument cluster in this example.

**** Illuminated:  The radio lights / display backlighting came on for a brief second then went out.

IMHO:  In my Humble Opinion

RPM's:  Engine rev's OR Revolutions per Minute

"Hex - Com" : Connector cable from the car diagnostic port to the computer

with Vag - Com software on it.

Vag - Com is diagnostic Software for Volkswagon and Audi.

Vag - Com is the property of Ross-Tech.com and its respective owner's.

The "Hex - Com" photo is from their web page.

This page is a step by step review of my experience, with their product, I bought.

It is for informational purposes only: 

-Scott  02/09/2005