As I have been posting, just put new heads on my truck. After reassebly am not getting rough idle at times and a p0351 code. I dont see or feel anything loose, but im also having a hard time believing that they coil failed just from being taken off and put back on. Any ideas?

Ford P0351 OBD-II Trouble Code Definition:

P0351 Ignition Coil 1 Primary/Secondary Circuit

P0351 Ford OBD-II Trouble CodeDescription:

OBD Trouble Code P0351
Ignition Coil “A” Primary/Secondary Circuit
What does the code mean? OBD-ii Code P0351 definition:
The COP (coil on plug) ignition system is what is used on most modern engines. There is an individual coil for each cylinder that is controlled by the PCM (powertrain control module). It eliminates the need for spark plug wires by putting the coil right above the sparkplug. Two wires are dedicated to each coil. One is a battery feed usually from the power distribution center. The other wire is the coil driver circuit from the PCM. The PCM grounds/ungrounds this circuit to activate or deactivate the coil. The coil driver circuit is monitored by the PCM for faults If an open or a short is detected in the driver circuit for coil number 1, a P0351 may set. Also, depending on the vehicle, the PCM may also shut down the fuel injector to the cylinder also.

edit:

CEL was still lit when I went out and did some more testing. Truck was running/idling fine. Pulled code again, then cleared codes. Seems to still be running normal. Did a 22 mile drive to the grocery store and ran normal. Lets just hope that it was the computer getting confused about something while it was relearning how to drive.

 

Ranger engines don't utilize a coil-on-plug (COP) design, so it has to be related to something else.

First thing is to double check the plug-wire configuration, keeping in mind that the cylinder layout is not the same as the coil pack layout.

 

According to some of the other forums (rangerforums.com, etc) they seem to be under the impression that this code is bank one of the coil pack. But isnt there a separate code for that? Strange to get a code that does not apply.

The problem that I felt when it lit the CEL was really rough at idle, but did not do it again and did not repeat in the next 4 on/off driving cycles. So dont know. Guess for now its drive and test some more.

Thanks!

 

reupdate, put another 25 miles and 5 on/off cycles on the truck today. No acting out or CEL, so maybe for now we put that up to truck was just confused with its heart valve transplant.