rossej

I've had random misfires on almost all cylinders and need some input.

The car is a 1999 Audi A6 Wagon Avant 2.8L with 133,000 miles.

Here's a what VAGCOM says:

Wednesday,09,January,2013,22:45:24:46126
VCDS Version: Release 11.11.5

Address 01: Engine Labels: 078-907-551-AHA.lbl
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D03
Software Coding: 06252
Work Shop Code: WSC 02325
VCID: 6CD93F721C3FD978ED4
5 Faults Found:

18010 - Power Supply Terminal 30
P1602 - 35-10 - Voltage too Low - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - Intermittent
16685 - Cylinder 1
P0301 - 35-10 - Misfire Detected - Intermittent
16816 - Main Catalyst; Bank 2
P0432 - 35-10 - Efficiency Below Threshold - Intermittent
16806 - Main Catalyst; Bank 1
P0422 - 35-00 - Efficiency Below Threshold

Readiness: 0000 0100




Codes were cleared. While entering the freeway, I was getting on the throttle pretty hard. I got up to speed and then let off significantly to stop my acceleration. That's when I noticed the engine shaking pretty hard for a couple of seconds; the CEL started to flash. Then it stopped flashing and everything was normal. Pulled off and scanned the car:


Monday,14,January,2013,17:26:04:46126
VCDS Version: Release 11.11.5

Address 01: Engine Labels: 078-907-551-AHA.lbl
Control Module Part Number: 4D0 907 551 AH
Component and/or Version: 2.8L V6/5V MOTR AT D03
Software Coding: 06252
Work Shop Code: WSC 02325
VCID: 6CD93F721C3FD978ED4
9 Faults Found:

16816 - Main Catalyst; Bank 2
P0432 - 35-00 - Efficiency Below Threshold
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - Intermittent
16685 - Cylinder 1
P0301 - 35-10 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 35-10 - Misfire Detected - Intermittent
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - Intermittent
16685 - Cylinder 1
P0301 - 35-10 - Misfire Detected - Intermittent
16689 - Cylinder 5
P0305 - 35-10 - Misfire Detected - Intermittent
16795 - Secondary Air Injection System
P0411 - 35-10 - Incorrect Flow Detected - Intermittent
16686 - Cylinder 2
P0302 - 35-10 - Misfire Detected - Intermittent

Readiness: 0000 0000

That was last weekend. I drove the car over 360 miles back home without noticing anything wrong. I even had vagcom out monitoring for misfires while my wife drove for a while. Nothing.

Fast forward to today:

Cleared codes again. I started the car at idle in the parking lot and monitored the misfire count on measuring block 15 and 16. Nothing happen until I got 8 misses on cylinder 6. After that, nothing.


What's the solution? Many thanks in advance.

jcman

18010 - Power Supply Terminal 30
P1602 - 35-10 - Voltage too Low - Intermittent

Yep these two are the critical first two on the priority "chain" of events that are causing the aftermath failures of the others following in order with possible exception to the SAI problem.

This similar issue was brought up before with a member who has a 4.2 and I don't recall his remedy with these codes.

STF the P1602 code because the 18010 is the same in definition, I do know that this is a low power problem to the ECM terminal 30 and could be caused by a low battery condition or power drain

redbullgotwings

Im not nearly as smart as jcman seems to be so i would listen to him and try and fix the power supply voltage too low first.
but i know when there are a lot of random misfires it could be caused by some vacuum line issues.

2.7Lturbo

jcman is on track with the power supply issue, if the ECU isnt getting correct voltage/current, you can bet your *** the spark plugs arent either

rossej

It looks like the member who owns the 4.2 solved his problem by changing his fuel filter.

Could a weak battery cause this code? My battery was getting weak; it was replaced a couple of weeks ago, a bit before the misfires started.

If this was the root of the problem, shouldn't this code have shown up after the second VAG-COM scan. There were certainly more misfires on more cylinders then. Just a thought...

rossej

Tips for checking vacuum leaks?

jcman

Misfires can be caused by a array of problems from timing issues, a bad coil, cross-firing wires, weak plugs and on and on including a vac leak yes.

Also bad gas with water in it, and in Philhawtins case a restricted fuel filter.

But the one issue that Grant aka JustMe pointed on was a failing ignition switch that could lend to the power drop noticed at term 30.

Sometimes our ECM don't see events that lead to others

redbullgotwings

yes a weak battery could for sure be the issue. if your battery is reading less than 11.5 with the car off then you need a new battery.

and on the vacuum lines. they are located in a little cluster on the back of the engine directly in the center. you'll have to move some stuff to get to it but it wont be too hard its right there. there is about 3ft of vacuum line to check and most of the time its obvious when there is a leak. most of the time it breaks off and most of the time it will be right next to an adapter/valve.

if you do have to change a vacuum line BE CAREFUL with the little plastic male end that the hose attaches to (on the valve or adapter). it will break very easily.

i personally dont think its a coil just cuz its kinda rare for the coils to go bad in these. but if you would like to try and replace the coil/distributor i have an extra used KNOWN WORKING one here at my house cuz i thought that was the problem with one of mine.

first thing i would do was take a reading on the battery and see if its at least 11.5v (or close to it) and put some new spark plugs in it.

some seafoam might be a good investment too.

xips069

ICM's get some that you know work. I had a bunch of the same codes you have going on with my a6. Also when you install them you need to put silicone heat sink grease on the mounting surface so they don't get hot and bug out like the ones you have now are probably doing. I found some used for $60 for 2 of them and there bosch off cl guy said they came from a good running car and when I put them on last night my misfire was gone. I did coils first and was wrong.

This is the parts you want.

http://www.ebay.com/itm/BRAND-NEW-GE...432948?afsrc=1

Nialist

Just wondering if you ever got a definitive fix on this. Since it's been months, i am assuming the ICM's solved your problem?