# Ignition Coil A-D Primary Secondary Circuit Errors



## valevue (Feb 24, 2008)

I bought a 2001 Jetta for my son. It has the 2.0L AVH engine code. If I clear the codes and start it up, within a minute or two I will get all four code P0351, P0352, P0353 and P0354. 
Initially, when I test drove the car, it ran very rough and had a misfire code as well. I corrected that by simply changing plugs and wires. The engine runs very smooth at this point but I still have the after P0351 - P0354 codes.
I found some good info on this forum related to these codes, specifically the ground fix. I was actually disappointed when I found this car already had that fix... wire from J6-1 to ground. I have completely cleaned all the ground points in the engine compartment and redid the EC to be sure it was done properly... Needless to say, I'm still getting the same error codes 1-2 minutes after startup.
I have had the coil out and polished it looking for the cracks and it looks great. The manufacturing date on the coil is 12/05 so it's clearly been replaced before. In fact I have paper work that came with the car indicating it was changed in 6/08.
Not sure where to turn next... especially with the engine running so well. Any idea what might be causing this? If this wasn't an inspection issue I would be tempted to install the black tape over the check engine light


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## valevue (Feb 24, 2008)

*Re: Ignition Coil A-D Primary Secondary Circuit Errors (valevue)*

Some additional information that I collected...
Coil Resistance Measurement Data: (Re. 6 Pin coil connector)
1-2 = 13.98K ohms (Primary 1)
1-3 = 13.98K ohms (Primary 2)
1-4 = 13.98K ohms (Primary 3)
1-5 = 13.98K ohms (Primary 4)
1-6 = 5.74K ohms (Gnd - Plus)
All measurements from primary to secondary are high enough to appear open on my Fluke meter. All measurements between mount collars, primaries and secondaries are open. This seemed normal to me, but then again, I'm the guy with unresolved codes :-/


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## valevue (Feb 24, 2008)

*Re: Ignition Coil A-D Primary Secondary Circuit Errors (valevue)*

Any thoughts on this one? Still pulling my hair out. Recognition that I'm SOL would even be appreciated.


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## Jetta704PZ (Oct 11, 2009)

*Re: Ignition Coil A-D Primary Secondary Circuit Errors (valevue)*

Sorry for the lack of feedback. As a former systems engineer, I'd say you've done an admirable job of testing and fixing. Since the codes begin a few minutes after startup, I'd surmise that's because the mixture goes from richer to lean and the changing resistance (impedance?) of the spark causes the coils to begin failing. There is a recall on some VW's coils, though I'm not well versed enough to say whether your's is affected.








Have you tried spraying a list mist of water to check for arcing?


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## valevue (Feb 24, 2008)

*Re: Ignition Coil A-D Primary Secondary Circuit Errors (Jetta704PZ)*

I left town for two weeks for the holiday season... hence no response. I haven't done the misting test but I have done the dark garage test and didn't see any fire flying. Now that I'm back home I will get the car back in the garage and I will run the mist test and see if there is any reaction. Thanks for your response... much appreciated.
Happy New Year


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## valevue (Feb 24, 2008)

*Re: Ignition Coil A-D Primary Secondary Circuit Errors (valevue)*

Started the car today to go for a new set of tires. 1st time it had been started in 3 weeks or so and it's about 10F out. Started good but ran a little rough and threw a Cyl 1 misfire code for Cyl 1 P0301 along with my P0351 - P0354 Ign Coil A Prim Sec Ckt codes. This is the first time I had a misfire since I changed the plugs and wires.
Openend the plenum up and continuity checked from the the T121 connector on the ECM to the T6 connector on the ignition coil and everything looks very good. Also monitored the voltage at the coil while the car was running and it was at a strong 14.25V. 
Still puzzled... I have this spark plug thought in the back of my head, maybe someone could share there experience... The AVH engine calls for NGK PZFR5D-11 plugs but when I bought my new plugs they sold me Bocsh Platinum +2 4303. Is there a possibility that the plugs could cause this problem?


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## Jay-Bee (Sep 22, 2007)

*FV-QR*

Yes, plugs could be 'part' of the issue, stick with the OEMs.
Have you heard about the coilpack ground fix? I have an AEG so mine is different, but I hear a lot of people talk about it on AZG/AVH engines, there is even a TSB for it.
Either that or maybe a new coilpack.


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## valevue (Feb 24, 2008)

*Re: FV-QR (Jay-Bee)*

I went out bought the NGK plugs and installed them moments ago. Reset the codes and started the engine. Within 1 minute I had the CEL and the P0351 - P0354 codes.
Jay-Bee - Yes I read about the TSB and this car already had it installed. I went back and replaced the connector and cleaned all the grounds just to be sure. I think my voltage check right at the coil is pretty good proof of good supply voltage and good ground. 
I priced the coil out and it's $200. If someone could run a ohm check on a known good AVH coil that would be great. You will see my numbers in a previous post above.


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## cwcabrio (Dec 16, 2009)

*Re: FV-QR (valevue)*

I Don't think the ohm test is any good in this coils. Just measured a bad coil and a good one and throw same values.
Any friends with same coil?


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## valevue (Feb 24, 2008)

*Re: FV-QR (cwcabrio)*

Ahh - that's very interesting... I appreciate the feedback! I don't think I have anyone to swap with though. I may have to bite the bullet.


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## cwcabrio (Dec 16, 2009)

*Re: FV-QR (valevue)*

Forgot to ask, what plugs you put on?
Gap them?


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## valevue (Feb 24, 2008)

*Re: FV-QR (cwcabrio)*

I put in NGK PZF R5D-11 plugs and gapped them at .040. Before that I had the Bosch Platinum +2 4303's which don't require gapping. I suppose they were fine but I figured it was worth a shot.... This problem has me possessed!


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## valevue (Feb 24, 2008)

*Re: FV-QR (valevue)*

Good news!!
It warmed up today making it comfortable to work on the Jetta again. I had thoroughly been through the wiring... 12V, GND, and the 4 wires from the ECM and was 100% sure that my connections were good. 
I installed a new coil and it fixed the problem. The P0351-P0354 error codes are gone and the CEL stays off. I'm once again a happy VW owner http://****************.com/smile/emthup.gif 

Thanks for the help along the way!!


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## cwcabrio (Dec 16, 2009)

*Re: FV-QR (valevue)*

Sure no problem. Glad you're back on the road.
Enjoy your ride.


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