Need help deciphering some DTCs

**Ele7eN** · 10-10-2008 02:19 PM

My MIL came on the other day, so I hooked up the VAG-COM and here is what I found:

6 Faults Found:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 008 - Implausible Signal - Intermittent - MIL ON
16685 - Cylinder 1: Misfire Detected
P0301 - 008 - Implausible Signal - Intermittent - MIL ON
16691 - Cylinder 7: Misfire Detected
P0307 - 008 - Implausible Signal - Intermittent - MIL ON
16686 - Cylinder 2: Misfire Detected
P0302 - 008 - Implausible Signal - Intermittent - MIL ON
16689 - Cylinder 5: Misfire Detected
P0305 - 008 - Implausible Signal - Intermittent - MIL ON
16687 - Cylinder 3: Misfire Detected
P0303 - 008 - Implausible Signal - Intermittent

My first thought was coilpack given VAGs track record with coils over the last few years. Then I realized that there are misfires in 6 cylinders, and it seems pretty unlikely that 6 coils went bad. I looked up the DTCs in the Bentley manual, and this is what it said:

Misfire Detection

Check fuel injectors
Fuel injectors, removing and installing
Fuel rail with fuel injectors - component overview
Ignition coils with power output stages checking
Overview of component locations

Has anyone here experienced this issue? It seems to come and go. The MIL came on about three weeks ago and promptly went back off a few days later. Being the lazy procrastinator that I am, I waited for it to come back on before checking the DTCs. I'm thinking that it must have something to do with the fuel rail, but I guess it could be six bad coilpacks...lol.

**WinterRunner** · 10-10-2008 02:22 PM

Is there a noticable loss of power? Just curious....

**Ele7eN** · 10-10-2008 02:26 PM

Originally Posted by WinterRunner

Is there a noticable loss of power? Just curious....

no, but it does seem to run a little rough at start up. in my google searches i found someone who had the same DTCs and they were caused by a bad MAF. I think I'm going to disconnect it and see if the DTCs go away.

**Ele7eN** · 10-10-2008 02:40 PM

I have changed the plugs since the first time the MIL came on, so it's most likely not the plugs.

**ChronicTeutonic** · 10-10-2008 04:43 PM

You tried checking the coils? The manual has a section that details the procedure. You don't need many tools, a test light and a voltmeter. I'm almost thinking that with so many out at once you may have a fried ECU??

**Ele7eN** · 10-10-2008 05:28 PM

Originally Posted by ChronicTeutonic

You tried checking the coils? The manual has a section that details the procedure. You don't need many tools, a test light and a voltmeter. I'm almost thinking that with so many out at once you may have a fried ECU??

no, i haven't done the test procedure. i guess i could swap coils from one of the misfiring cylinders to one of the good and see if the misfire moves to the other cylinder. i really don't think that's the problem though. i just ordered a new MAF. hopefully that will solve the issue. otherwise, i may have to resort to bringing it to the dealer.

**webstir** · 01-30-2009 09:37 PM

Did you find out what was causing your random misfires? I am having the same problem and was hoping you had some success in tracking down the source.

**RAudi Driver** · 01-30-2009 09:41 PM

did this just happen on startup or while driving the car? Also, what kind of car do you have.

**ieatfishburitos** · 01-30-2009 09:57 PM

Originally Posted by webstir

Did you find out what was causing your random misfires? I am having the same problem and was hoping you had some success in tracking down the source.

This guy hasn't posted in the forums since 10/30/08, you should probably send him a PM to get any chance of a response.. The PM will send him an email, where as the post in the forum will not unless he is subscribed to the thread. Good luck!