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Engine Misfire Issues: P2302

14K views 13 replies 5 participants last post by  BEWARE 
#1 · (Edited by Moderator)
Hello, I have had some trouble tracing down some issues I have been having with my 2007 JKU with 165k miles on it. When I start it up, there is a solid check engine light and after about 30 seconds of running, the idle gets really rough and the check engine light starts blinking.

I have engine codes:
P0300 Multiple Cylinder Misfire
P2302 Ignition Coil 1 Secondary Circuit - Insufficient Ionization

So far I have replaced the plugs, wires, and coil pack all with mopar replacements. Hoping to not have to keep dumping money into it by simply trying to guess what it is. I also check/cleaned the grounds on the fenders and they seemed fine.


Not sure if its related, but the engine also has a small coolant leak at the intake manifold, and sounds like it might have a small exhaust leak at the headers at start up but always went away once warmed up. These have been around for a while but the codes are new.

Thanks in advance.
 
#9 ·
I was just going to chime in on this.

I've had similar issues with O2 related codes. After numerous rounds of replacing the sensors, I swapped in a new main engine wiring harness, thinking maybe it had been damaged (Mr. Nibbles anyone?). That offered no improvement.

Which led me to suspect an issue with he connector on the PCM or something within the PCM itself, since everything else had been replaced and checked and double-checked ad-nausea.

New PCM is on the way.
 
#10 ·
Yeah, after reading every forum post related to the two code combination, it seemed most time it was a bad PCM. After confirming wires between PCM and coil pack were good, I decided to do it. I even tore apart the PCM hoping to see something burned out I could replace but did not notice anything.
 
#12 ·
what was the verdict in getting the new PCM?

Ran into the same problem p0300 and p2302


I changed fuel injectors coil pack plugs and wires/plug cables
cleared codes and I'm still getting p2302

your help in this matter would be greatly appreciated
thank you in advance
B
 
#13 ·
my new PCM is still sitting in the box... Switching it is a pain for me because of the custom RIPP tune I'm running.

I bought a new house, and everything else was shifted to the back burner. Once I get the new shop put back together, I'll get it swapped out.
 
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