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Bulletin PIP5201 Cold Start Misfires MIL P0300 P030x

5290 Views 16 Replies 5 Participants Last post by  DMC5180
So for the past few days, I've had the check engine light start flashing when the battery finally dies and it kicks into engine mode. It's also stayed on twice after it's flashed. Checked the code with my OBDII scanner and the first 2 times it was P0303. Last night on a a test drive, I could only get it to flash, not stay on, and the code that showed up was P0300pd. I tried to swap coils, but realized it was a weird "all in one" coil pack that I've never seen before and I couldn't just swap colls to see if # 3 coll was bad. My engine only has about 30k miles on it, the rest of the 67k is all battery miles. So I can't imagine the plugs would need changed already, since they're supposed to be good for 100k.

One interesting thing to note... I have had this wheel vibration that's gotten worse over the past month or so, and it's gotten pretty bad just recently, almost maybe coninciding with the CEL. I read in the manaul that a flashing CEL could be caused if I used different tires than OEM, which is weird. I'm wondering if the vibration is somehow triggering the code/CEL??? Anyone ever experience anything like this? Any suggestions? In the mean time, I guess I'll fix the wheel vibrations and see if that fixes it. If not, I'm thinking replace the "coil pack bar" or whatever it's called and see if that does the trick. Any thoughts or ideas are welcomed.
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You might want to fix the vibration first and reconfirm (especially if you are not really feeling/hearing/detecting a steady misfire as being present)
There has been cars where a bad vibration affected the misfire diagnostic
The diagnostic detects crankshaft speed irregularities via the crankshaft position sensors continuous signalling and chassis vibrations can certainly impact this

I'd like to know what makes this a 2012 Volt specific issue? Did the they change the head design for 2013 model years. I found the service letter but could not access the full document without paying a $5 one time fee for that info. The title was " Cold start misfires MIL P0300". (Jan-25-2017)

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I'll buy it and post it so we can all see what it has to say.
Nothing in the head was redesigned as far as I am aware (and nothing stated to that within the bulletin)

In fact, the preliminary bulletin is comprehensive in it's directions to inspect NUMEROUS potential causes for a "cold start misfire" including ignition and fuel system checks.

Instructions to perform "top end" cleaning is an item mentioned specifically deeper into the document, and if unable to alleviate the misfire after doing so (and all previously listed diagnostic checks) the head it to be replaced and the customer advised to use ONLY TOP TIER FUELS (specifically formulated to help keep injectors and top-ends free of carbon deposits)

Again, no head redesign or anything and AFAIK it's the same part number. But I too am curious as to what makes this specific to the 2012 models (but will try to find out)

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