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If your check engine light or malfunction indicator lamp is on and the code scanner reads "P0351, P0352, P0353, P0354, P0355, or P0356, Ignition coil circuit fault," the last digit in the code is what cylinder # is causing the fault.

P0351 would mean the ignition coil on cylinder #1 is causing the fault. If it reads P0352 then the ignition coil on cylinder #2 is causing the fault..... you get the idea! Hopefully it's 4, 5, or 6 since they are the easy ones to get to on the V6.


Direct image link http://i603.photobucket.com/albums/tt11 ... cation.jpg

You could replace the coil for around 100$ like i did only to find it wasn't the problem. Or try this first.

Let's say the code scanner reads "P0354". Take ignition coil #4 out and switch it with coil #5 or coil #6 (or any other coil) and use the code reader to clear the codes. The check engine light or malfunction indicator lamp will go out. Then drive until the check engine light / malfunction indicator lamp comes back on. Mine took about 5 minutes of driving. Read the code again. If it still says error "P0354" then odds are it's the wire from the PCM to the coil.

Every coil has 2 wires. One wire is the same on all coils. It is white with a purple stripe. This is the power for the coils and is not coming from the PCM.

The second wire is the ground wire. Every coil has a different color. It is coming from the PCM and most likely the broken one. I have read there is a TSB on this issue but couldn't find any info about it. They also say the break usually happens within 3 inches from the PCM.

First, check the connectors at both the coil and the PCM for carbon tracking, corrosion, or spread pins. If you find any, fix them.

If you want to check the white with purple stripe wire at the coil (the power wire), use a volt meter. Put the key in the run position without starting it. It should have 12 volts. If it does then you know it's good and should move on to the wire leading to the PCM. But if it doesnt you should check another coil's white/purple wire for 12 volts. If only the one coil's white wire doesn't have 12 volts then you can jump off of another coils white/purple wire. For example if coil #4 doesn't have 12 volts, but coil #5 does, put a jumper between the white/purple wires for coil #4 and coil #5.

Getting started on the PCM wire
Like always, unhook the negative battery terminal

There is a plastic guard on the PCM. To remove it, cut the tape that wraps around it and squeeze the top and bottom to release the tabs and pull it straight off. It comes right over the 10mm bolt (you dont have to remove the 10mm bolt to remove the guard). Once it's off use the pinout diagram below to find the wire you're looking for. Mine was P0351 coil #1 so i found pin 26 on the PCM (GRN/WHT wire) and sure enough within 3 inches of the PCM i found a break! If you wrap the wire half way around your finger and slide your finger down the wire you can usually feel if the copper wire is broken inside the insulation. If you find the break, cut then strip the wire and repair the break. I recommend soldering and using heat shrink to cover it.


Direct image link: http://i603.photobucket.com/albums/tt11 ... edwire.jpg

In some cases (like mine) this didn't fix the problem. :wall: Go over the wire again and see if you can find another break in it - I couldn't find one so i decided on running a whole new wire.

Cut the correct coil wire close to the PCM, BUT NOT TO CLOSE because you're going to have to solder a new wire onto it. I left about 1 inch and that was plenty. Then cut the corresponding wire at the coil. I also left about 1 inch and ran a new wire from the PCM to the coil using 20 gauge "stranded" wire.

Try to keep it with the other wires since they are already out of harms way. I zip tied it along the harness the whole way down to the coil.


Direct image link: http://i603.photobucket.com/albums/tt11 ... ewwire.jpg

After running the new wire you can either use the code reader to clear the codes again or, since the battery was disconnected the whole time, they might be cleared already and if that doesn't fix it.........well i wouldn't know cause that fixed mine. But I would say your PCM is bad or the connection going into the PCM or going into the coil are bad.

PCM pinout diagram
If the picture is too small for you to read you can right click on it and click on "Save as" or "save image as" and save it to your computer so you can zoom in on it.

Direct image link http://i603.photobucket.com/albums/tt11 ... r/PCM1.jpg

Direct image link http://i603.photobucket.com/albums/tt11 ... r/PCM2.jpg

Direct image link http://i603.photobucket.com/albums/tt11 ... r/PCM3.jpg

Sorry this is so sloppy and misspelled i'm new at this and never could spell
 

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Good stuff, I went over it and made some edits as you had asked me to.

If the wires deliver 12 V, the coils are still good, but there are still problems, don't replace the PCM just yet. I would disconnect both ends of the connector (so that no electrical components are within the circuit) and connect an ohmmeter to the ends. Then check for resistance spikes while wiggling the wire along the way. Sometimes you have a partial break which will deliver 12 V when you measure it, but will drop when it is under load.

The TSB you mentioned is here: viewtopic.php?f=24&t=134

It only applied to 2005 models, and it looks as if they had a bad batch of spark plugs which interfered with the PCM.
 

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I had a code P0351. I 've found the broken wire but there isn't enough to re-solder to. How do I remove the wire from the connector to the PCM and re-attach a new wire.
 
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