2005
F150
5.4
70,000 miles


My engine light came on right after a front brake job, I know that aren't related - but wanted to share all information.

Took it to AutoZone for reading, found the following with printout:
P0358 code
Ignition coil primary circuit condtions - coil number 8
CAUSES:
(1) Ignition coil defective
(2) Secondary ignition-plugs, wires, cap, roto
(3) Poor electrical connection or circuit fault
(4) Driver circuit fault-ignition midule or PCM

I read alot of folks with same code issue, but they all have rough running trucks. Mine is running smooth, not issues.
I did clean the NEG post of corrision build up. This reset code, but it came back.

I am running a large system: JL Audio 1000/1 amp and 2 JL Audio 12" w6

Sometimes when the sub hits hard, my lights will dim. Not sure if this might be related, but again wanted to share all of my setup. Looking for ideas. I don't want to start replacing coils, especially since it is ruuning good.

Please send any ideas.

 

At 70k, it's about time to change the spark plugs.

 

80 views over 3 days and only 1 reply
- no one has a similiar issue?

 

The coil may be partially functioning enough to throw a CEL but appear to make the truck run ok. A easy solution to that particular setup is swap the coil with another one, reset by disconnecting the battery, wait for it to throw another CEL and see if the new code points to a different cylinder or the same one. If it moves replace the coil, if it does not start tracing the wiring to cylinder 8 or take it somewhere if your not comfortable doing this.

 

Thanks - great trouble shooting suggestion. We will try it this weekend.

 

So what fixed it? So far i have found no one else with the same problem and you left me hanging?

 

Sorry man - we sold the truck. But I can report that the Engine Light went off on it's own and cleared the code.