Open Ignition Circuit? - Anyone run into this?

A6 All/ S6 All
#1

So last night I decided to put in some new sparkplugs, finish up, start the car up and its idling a bit rough. I pull the codes and now I have misfires and a code for ‘Open Ignition Circuit Cylinder 3’. I’m in a pinch now because I can’t to either of my two jobs today >:(

iirc cyl. 3 is passenger side second from the firewall, so I swapped coilpacks around, didn’t change… then I decided to put the old spark plug back in, no help. I did the same again this morning and again no change.

I also went and pulled the ground strap off by the coolant overflow tank and cleaned up the connectors and hit it with some dielectric grease to make sure the ground was good but it didn’t do anything.

Anyone every run into this issue/have any advice? It seems like it has to be something in the connector/wiring from the cyl 3 ignition coil, and I didn’t yank around on the wiring at all so I doubt its damaged.

#2

I did some research and this is what I found.

  • Fuel Pump Relay, I guess this is tied into your fuel injectors as well as your ignition system? weird but thats one thing I would check. It may not be a misfire at your plugs but a injector thats not firing possibly.

  • ECU Fuse or any of them, Check your fuses

  • Check any grounds you may have bumped

  • You might have touch something and shorted it out.

  • Check for voltage at your injector and ignition connectors

#3

yeah, I would have guessed something with the connection as well once you did the elimination tests. Odd.

did you google the code? This thread is interesting

http://forums.fourtitude.com/showthread.php?2382004

Jetta owner, but a VW tech talks about it a bit.

Then a guy with a 2000 A6 also pipes in at the end.

#4

^I actually didn’t see that thread, but I’m going to do something similar.

My grounds and main supply are good, but I’m suspect of the tiny ass signal wire from the ECU. I’m going to run an overlay from pin 3 of the coilpack connector to pin 111 of the ECU.

I’ll post my diag of the grounds/feed in a moment.

#5

Well I broke out the Bentley and here’s how the wiring to the connector looks:

Pin 1 - Constant Feed, common to each bank
Pin 2 - Ground
Pin 3 - Signal from ECU
Pin 4 - Ground

Now to test them I did the following with my multimeter:

  1. Measure battery voltage from terminal to terminal
  2. Pin 1 - Lead to pin 1, lead to negative terminal on battery: Voltage = Battery Voltage
  3. Pin 2 - Lead to pin 2, lead to positive terminal on battery: Voltage = Battery Voltage
  4. Pin 4 - Lead to pin 4, lead to positive terminal on battery: Voltage = Battery Voltage

So with this I figure there’s a good chance something between the coilpack connector pin 3 and ECU connector pin 111 isn’t right. I’m going to test resistance and then try and overlay to see if that will do it. Hoping for the best here.

#6

fixed?

#7

yup, it was the wire from pin 111 to pin 3. broke loose in the connector

#8

Smart man, great to see you found the problem!