Today while driving the check engine light came on. Ran a little rough and then seem to smooth out.

ID = P0355
Status = $07E8
Description = Ignition coil 'E' primary control circuit/open

Any ideas or pointers?

 

Cylinder #5 (coil E) is not completing the primary circuit so, in essence, the coil cannot complete the secondary circuit and fire the spark plug. Could be a faulty coil (or intermittently faulty) or the wiring harness, or connector to the coil either permanently or intermittently failing or failed.

I would first do the physical inspection of coil #5. Check the connector. Unplug it, I would use an electronics connector cleaner, reconnect it, erase the P0355, see if it comes back.

Then another step, w/o spending any money, is switch #5 coil with any other coil, erase the P0355, see if it comes back as a P0355. If you switch it with coil F for example,(#6 cyl) see if a P0355 appears or a P0356. If a P0356, then the coil is bad. If still a P0355, then something in the harness getting the signal to #5 is bad.

These are the easy steps.

 

Thought I would add one more piece in case there is question:

$07E8 - describes the system where the power train fault (the P0355) occurred. $07E8 IDs the engine control unit (ECU or ECM, or PCM - same)

A $07E9 would mean the transmission control module (TCM) is the system where the fault generated. Of course, an engine coil failure could not have been generated by the TCM, but power train faults do include transmission faults which start at P07xx