So the "raised square" might be the "rib."

 

Yeah, the raised Square and the rib are the same.
Next question: Am i missing something? I dont found any Ohm values or instructions how to meassure the Coils electrical to check for damage in the Service manual.
Meanwhile, i asked one car mechanic, one Master car mechanic with knowledge in Car electrics and one "Mechatroniker" of my friends about these possible differences in ignition coils. I showed them the part of the Honda FSM where Honda warns about mixing the Ignition Coils. Everybody was: What? Have they changed the saprk plugs also? No? Install them...

If this really was a serious concern that something could be damaged, Honda would probably have created a TSB (Technicall Service Bulletin) for the dealers?
Could somebody here talk to some higher ranks of Honda North America and ask a Technican there about a explanation what was changed in the Ignition coils or the ECM between the years to solve this riddle?
Otherwise, we probably could fill another 10 Pages with brainstorming and guesswork. Wich is basically fun and interesting, but..

 

All so confusing. And the superseded parts numbers, and various engine years.

 

I think I may have figured it out. An answer that addresses all the confusion, wraps it up with a bow.

First, what would impel Honda to make a change to begin with? Some change that coincided with 2006 model year that could have required a corresponding change to ignition coils?

No, dbw wouldn't make sense. But what would, XM radio. Very sensitive to ignition system RFI. The logical change to address that would be a change to coils. Simply increasing internal resistor to prevent high frequency radio emissions.

They'd also make changes to ecu programming to load up coil with more energy before firing to compensate. Same ignition energy, no XM interference.

Results:

Using OEM coils meant for older car in newer, annoying XM radio interference on the few cars so equipped

Using newer coils on older cars much more problematic. While they'd work, spark would be weaker. In adverse conditions, misfire would occur sooner. Worn plugs, worn engine, aging coils, etc.

Since most of us maintain our cars so well, such misfires perhaps less likely than ordinary cars. So using newer oem coils on older engines, not advisable, but would mostly work.

Older coils on newer car, no issue unless you have XM radio.

Honda wouldn't want to make special coils just for markets that use XM radio, nor the special ecu programming to go with. So they'd make them all the same in all markets, so the same rules still apply in all markets.

But what would aftermarket suppliers do? Why make special coils for such a limited subset of a limited production model? Very few owners bought the XM option.

In markets that didn't even offer XM, aftermarket would have even less incentive to make model specific coils.

Hence in all likelihood, aftermarket coils are universal, and made to accommodate pre '06. So they're fine in all models, except they'd cause XM radio interference.

That aligns to what we see. Honda says DON'T mismatch coil and car, aftermarket says they're universal.

So buying aftermarket, don't worry about it. Use whatever is high quality. Buying OEM, actual Honda parts, then it likely does matter. Make sure to match coils to cars.

 

Totally fine. Probably 2000km on them and 5 or so track days.

For fun, I pulled a couple out this morning and inspected. They look good as new.

 

I am just about to order some for my 2009 and want to be sure I am getting the right thing. I have searched some Honda parts online and what I think is the correct part number changes to 007 at the end instead of S01 and it says it fits my 2009. It does not. Tried AI and got the following. I am ordering from Japan at $145 a pop.






I pulled one from my 2009 to see what I might find. These are the original OEM ones with 87K miles.


​​​​​​​There is no raised square on these.

 

Good luck with your purchase. Tell us how the new parts look compared to the ones on the car now. Once you receive them.

 

Yes the raised square is right there.

 

Also has the 2nd rib on the head of the coil too. So the -117, and both of those ribs/raised square would seem to indicate those are 06+ going by what everything else says. Abd matches the year model. So like the FSM shows, having both ribs at the top seems to be only on the 06+. Mine do not have that 2nd rib on the top and are -115

 

Im still very suspicious of the rockauto ngks. Canucks did not fit at all and mine fit fine but the materials failed miserably. Both the cracking and the melted portions lead me to believe either NGK used crap or incorrect material (not likely) or they are not really ngk.