P0356 and P0306 codes

[Eric Suderman]

Recently totaled my 02 but got a hold of another one with a rough idle for a screaming deal (I hope) it pulls a pretty constant P0356 code (ignition coil f primary/secondary circuit) will also pull a P0306 code (misfire cylinder 6). The second code generally comes on after a change in speed on a longer drive, and causes the engine light to flash (I'm not currently driving it). It has new plugs and coils, and I swapped the cylinder 6 plug, coil, and wire connector from the totaled jeep and a circuit tester showed power going to that coil. Swapped the ASD relay which also changed nothing. Any suggestions? What did I miss?

 

[Eric Suderman]

Recently totaled my 02 but got a hold of another one with a rough idle for a screaming deal (I hope) it pulls a pretty constant P0356 code (ignition coil f primary/secondary circuit) will also pull a P0306 code (misfire cylinder 6). The second code generally comes on after a change in speed on a longer drive, and causes the engine light to flash (I'm not currently driving it). It has new plugs and coils, and I swapped the cylinder 6 plug, coil, and wire connector from the totaled jeep and a circuit tester showed power going to that coil. Swapped the ASD relay which also changed nothing. Any suggestions? What did I miss?

The old coil had been leaked on from the coolant reservoir but has not been since being swapped

 

[Billwill]

What plugs are you using?

Worst case scenario is that you swap over the Ignition Keys, SKIM Module at top of steering column and PCM from the totaled Jeep to the present one....maybe the PCM is faulty...you cannot swap over the PCM by itself without programming in the SKEES code!

 

[Eric Suderman]

The pcm by itself won't work? I forgot to list it but I tried that and it did seem worse.

 

[boxbuster]

You might try checking tbe camshaft position sensor and, as a long shot, the oxygen sensor on the passenger side if getting misfires on cylinders on that side and coils are ok.

 

[Eric Suderman]

You might try checking tbe camshaft position sensor and, as a long shot, the oxygen sensor on the passenger side if getting misfires on cylinders on that side and coils are ok.

Would either of those account for the p0356? Because I'm under the impression that what's causing that is also causing the subsequent misfire.

 

[boxbuster]

In the situation I had, yes...I replaced the camshaft position sensor and p0356 went away

 

[Billwill]

The pcm by itself won't work? I forgot to list it but I tried that and it did seem worse.

If you replace the PCM the Agents usually have to re-program the PCM to have the SKEES data entered to match the chipped ignition keys you have.

That is why the PCM, SKEEM Module on top of Steering Column and the Ignition Keys from the same Jeep can be moved across at the same time.

VIN should also be programmed into the PCM.

 

[Billwill]

In the situation I had, yes...I replaced the camshaft position sensor and p0356 went away

I agree ^^^

It would be a good idea to replace the Cam Sensor then the Crank Sensor if needed.

 

[Eric Suderman]

In the situation I had, yes...I replaced the camshaft position sensor and p0356 went away

I wouldn't have thought that, I know what I'm dying next

 

[Eric Suderman]

Changed camshaft and crankshaft position sensor and no change. Both were donors from the totaled jeep and weren't pretty so I may try new ones, but the totaled jeep wasn't throwing any codes.

 

[boxbuster]

As I mentioned earlier, you might also try changing the oxygen sensor. Your first post mentioned a P0306 code. If you are still getting that code as well, the oxygen sensor may still be the culprit. As you likely know, the #6 cylinder is the very back cylinder on the passenger side, so try changing out the oxygen on that side. I invested $10 or so for an oxygen sensor wrench from Amazon and it made for a fairly easy removal. If it's rusty, spray some wd40, pblaster, or CorrosionX (my most favorite of all, but pricey!) and wait a few minutes before removing. I wrapped a paper towel around the electrical plug (just to be on the safe side) and found it easier to disconnect this plug once I got the sensor unscrewed so it was hanging down a bit.
All this is assuming you are getting fire to your good plugs and good coils.
If the oxygen sensor change doesnt help, post back and I'll tell you what else you might try.

 

[Eric Suderman]

Changed the 02 sensor and the pcm/ignition switch/skeem. Still getting p0356, I would have to drive it to see if the p0306 still pops up but I'm going to assume it's still there cause I don't want my engine light to flash at me. I have a new cam sensor and crank sensor getting delivered today in case the donors were faulty. What else?

 

[tommudd]

Been mentioned before but what spark plugs are you using ?
Only NGK coppers should be in there
Guy bought one for a good price, was having codes pop up, misfiring
told him plugs and what to get, no the idiot had bought some brand of cheap plats and said they were new and good

I had a set of copper NGKs in stock, screwed them in , problem taken care of

 

[Eric Suderman]

A very corroded ngk came out (had a bad reservoir above it, maybe I forgot to mention) and got replaced with whatever was in the totaled jeep, as well as the coil pack. I could swap it with another cylinder to check but I'm not too optimistic.

 

[Eric Suderman]

I should also mention that a couple of times the engine light started flashing after the car shook while trying to accelerate. The light flashes any time the p0306 comes on, but with only the p0356 code the light is just on.

 

[boxbuster]

Hopefully the oxygen sensor change will at least get rid of the p0306. And, once you get the new camshaft and crank sensors installed, maybe your problems will be solved.

If not, you might consider investing in the following kit to further help in pinpointing your problem:
Tool Aid 23970 in-Line Spark Checker Kit for Recessed Plug

I paid less than $25 on Amazon and it really helps in troubleshooting.
You can watch some YouTube videos on how to use this type of kit and I also recommend reading the Amazon reviews for some tips and ideas on how to use it and make it work better.
I have used it to not only troubleshoot car problems, but also used on my lawnmowers too and wish I had known about this type of kit years ago!

 

[Eric Suderman]

Well, both KJs are going to scrap. Went to check the spark plug (again) and the coil pack was completely melted into the head, only half of it came out.

 

[tommudd]

Well, both KJs are going to scrap. Went to check the spark plug (again) and the coil pack was completely melted into the head, only half of it came out.

Going to scrap ?

 

[boxbuster]

Oh Man!
I'm so sorry to hear that!
Well, I replaced both heads on my 02 Libby.
The driver side head didnt have any problems, but the passenger side head broke a valve seat and banged the piston up a bit.
I dressed out the gauges in the piston with a dremel and so far, so good.
I decided to get both heads since they had new valves and seats and paid around $250 per head.
It was not too difficult a job, but time consuming since I decided to also replace the timing chains, guides and gears while I had the heads off.