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Busy Monkey
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4,461 Posts
Discussion Starter · #1 ·
Every day or so, usually after the engine has mostly warmed up, the engine pitch will increase and it will run rough, like one cylinder is missing, and there's a decrease in power. It lasts for up to 10 or 15 seconds and the check engine light comes on. Then it runs totally normal again.

I suspect a coil pack is going bad. Has anyone else had this problem? Do I just wait until it's constant? Or is there a way to figure it out now?

DTC detailed description:
P0351 Through P0360 - Ignition Coil A through J Primary/ Secondary Circuit Malfunction Each ignition primary circuit is continuously monitored. The test fails when the PCM does not receive a valid IDM pulse signal from the ignition module (integrated in PCM). Open or short in Ignition START/RUN circuit
Open coil driver circuit in harness
Coil driver circuit shorted to ground
Damaged coil
Damaged PCM
Coil driver circuit shorted to PWR

Thanks guys

P.S.
It's an '04 D23
 

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Premium Member
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21,256 Posts
Here's what I'd do:

1) Pull the plugs to see if there's any difference in the deposits on the plugs and you can determine which cylinder is affected.
2) Check the coil for resistance.
3) Check the wiring back as far as you can and look for damage.
4) Clean the plugs, swap the affected coil with another. After driving for a while you should be able to determine if it's a problem with that coil, or the wiring for that cylinder if you didn't find anything obvious in the earlier checks.
 

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Busy Monkey
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4,461 Posts
Discussion Starter · #3 ·
Thanks whynot

Sorry, I forgot to say I already pulled the plugs and they all look fine. I just looked at the wiring and it looks normal too.

How do I check the resistance of the coils?
 

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Premium Member
Joined
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21,256 Posts
Huh, I was hoping you could identify the problem cylinder by the spark plugs.

Unfortunately, I don't know what the resistance should be, but I'm sure someone here can check a manual for you. You need an electrical tester to go between the positive input and the output (where the spark plug connects) of the coil. Since you don't have a manual to go by, I'd check for the same resistance on another coil. The one with the higher number will be the bad one.
 

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Busy Monkey
Joined
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4,461 Posts
Discussion Starter · #6 ·
Alright, so I bought one new coil and replaced the coil on cylinder 1, then every week or so I've been working my way down. Finally replaced one and it ran a lot better, but still had the problem a little bit. Ran it that way for a while. Put the "bad one back in and it instantly got a lot worse. So I've got more than one bad coil.
I'll just get a new set of 4 coil packs and be done with it. The car is 5 years old anyway and those are probably the original coils on there.

P.S.
I checked the resistance and they are all nearly identical.
 
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