What Should I replace the COP and the plug or just the COP? Which cylinder is this? Sorry for the dumb questions.

 

P0354 - Ignition Coil D Primary/Secondary Circuit
<table border="1" cellpadding="3" cellspacing="0"><tbody><tr> <td style="border-right: medium none;" align="left" valign="top">Description: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">See the description for DTC P0350. </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Possible Causes: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">See the possible causes for DTC P0350. </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Diagnostic Aids: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">See the diagnostic aids for DTC P0350. </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Application </td> <td style="border-left: medium none;" align="left" valign="top"> </td> <td align="center" valign="top">Key On Engine Off </td> <td align="center" valign="top">Key On Engine Running </td> <td align="center" valign="top">Continuous Memory </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Coil-on-plug (COP) ignition testing </td> <td style="border-left: medium none;" align="left" valign="top"> </td> <td align="center" valign="top">— </td> <td align="center" valign="top">GO to Pinpoint Test JF. </td> <td align="center" valign="top">GO to Pinpoint Test JF. </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Coil pack ignition testing </td> <td style="border-left: medium none;" align="left" valign="top"> </td> <td align="center" valign="top">— </td> <td align="center" valign="top">GO to Pinpoint Test JE. </td> <td align="center" valign="top">GO to Pinpoint Test JE. </td></tr></tbody></table>
<table border="1" cellpadding="3" cellspacing="0"> <caption>P0350 - Ignition Coil Primary/Secondary Circuit </caption> <tbody> <tr> <th align="center" valign="bottom">
</th> <th align="center" valign="bottom">
</th> <th align="center" valign="bottom">
</th> <th align="center" valign="bottom">
</th> <th align="center" valign="bottom">
</th></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Description: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">Each ignition primary circuit is continuously monitored. The test fails when the powertrain control module (PCM) does not receive a valid ignition diagnostic monitor (IDM) pulse signal from the ignition module (integrated in the PCM). </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Possible Causes: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">

• Open or short in the Ignition START/RUN circuit
• Open coil driver circuit
• Coil driver circuit shorted to ground
• Damaged coil
• Coil driver circuit shorted to VPWR

</td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Diagnostic Aids: </td> <td style="border-left: medium none;" colspan="4" align="left" valign="top">Use the 12-volt non-powered test lamp to verify START/RUN voltage at the ignition coil harness connector.
Check the coil driver circuit for open, short to VPWR, or short to ground. </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">Application </td> <td style="border-left: medium none;" align="left" valign="top"> </td> <td align="center" valign="top">Key On Engine Off </td> <td align="center" valign="top">Key On Engine Running </td> <td align="center" valign="top">Continuous Memory </td></tr> <tr> <td style="border-right: medium none;" align="left" valign="top">All </td> <td style="border-left: medium none;" align="left" valign="top"> </td> <td colspan="3" align="center" valign="top">GO to Pinpoint Test JE. </td></tr></tbody></table>

<table border="1" cellpadding="3" cellspacing="0"><tbody><tr><th align="center" valign="bottom">Vehicle </th> <th align="center" valign="bottom">Related DTC </th> <th align="center" valign="bottom">Cylinder Number </th> <th align="center" valign="bottom">Ignition Coil </th> <th align="center" valign="bottom">Coil Driver (CD) </th> <th align="center" valign="bottom">PCM Pin </th></tr></tbody></table>
<table border="1" cellpadding="3" cellspacing="0" height="221" width="505"><tbody><tr> <td align="center" valign="top">F-150, Mark LT </td> <td align="center" valign="top">P0351 </td> <td align="center" valign="top">1 </td> <td align="center" valign="top">A </td> <td align="center" valign="top">A </td> <td align="center" valign="top">E17 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0352 </td> <td align="center" valign="top">2 </td> <td align="center" valign="top">B </td> <td align="center" valign="top">D </td> <td align="center" valign="top">E11 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0353 </td> <td align="center" valign="top">3 </td> <td align="center" valign="top">C </td> <td align="center" valign="top">B </td> <td align="center" valign="top">E12 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0354 </td> <td align="center" valign="top">4 </td> <td align="center" valign="top">D </td> <td align="center" valign="top">G </td> <td align="center" valign="top">E14 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0355 </td> <td align="center" valign="top">5 </td> <td align="center" valign="top">E </td> <td align="center" valign="top">F </td> <td align="center" valign="top">E10 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0356 </td> <td align="center" valign="top">6 </td> <td align="center" valign="top">F </td> <td align="center" valign="top">E </td> <td align="center" valign="top">E15 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0357 </td> <td align="center" valign="top">7 </td> <td align="center" valign="top">G </td> <td align="center" valign="top">C </td> <td align="center" valign="top">E16 </td></tr> <tr> <td align="center" valign="top"> </td> <td align="center" valign="top">P0358 </td> <td align="center" valign="top">8 </td> <td align="center" valign="top">H </td> <td align="center" valign="top">H </td> <td align="center" valign="top">E9 </td></tr></tbody></table>
Here's the info on your DTC. You can move the COP to a different cylinder to see if it follows. If it does, then it's probably the coil. If not, there are other things you will need to troubleshoot. The list is a little long as is the troubleshooting procedure. But that's where I would start, move the COP to different cylinder. Let us know what happens...

 

Thank you for your help wildcard30. I changed out the # 4 COP to the # 1 position. I went to a different autoparts store and had a guy read the codes. It showed all the COPS 1-4 were bad. (yeah the girl at the first autoparts store didnt know to press the down button to get more codes) So I went back home and did some more searching. Come to find out the wiring harness that controls the COPS was damaged. My local dealer has installed a new harness. Again thanks for the help.

 

No problem...

What caused the damage to the wiring harness?

 

Rodent damage. Must have happened in the winter months. I can't imagine a rat or squirrel wanting to climb up next to a hot engine in July??? The truck is parked outside and we do live in the woods. I leave it at our barn for several hours at a time so who knows. Never thought I would say I had a rat eat a wiring harness though.

 

At least the "bad harness" was not caused by something related to the truck itself....

Hopefully it did not cost much to fix.