Long story short, when I short the code connector during a no restart episode, I get the code for ICM problems. Is there anything else in the ICM circuit, or is that all that's checked? Also, I've read that ICM's often fail due to solder joints failing, not the ICM itself. Anyone ever try to open one up?

FYI, Here are the symptoms:
Rarely starts on 1st crank(turn of key) when engine cold,(any weather) 2nd crank fine, starts well.
In warm/hot weather, starts and runs OK, but if shut off within 10 mins or so often experiences no restart-ability. Cold weather, no problem.
Also has occasional cold engine idle surge.
Thanks for any advice!

 

The ICM is sealed, so I think that you will have to destroy the casing to open it.

You can check to see if the wires leading to it are loose or dirty.

Some auto parts stores can test them. I would call one before hand to see if they can test it.

 

Maybe you're thinking about the main relay solder joints.

I assume you mean code 15 - ignition output signal? That could be the wiring from the ECU out to the ignitor (or the ignitor itself is bad). There's something in the DIY section about troubleshooting coil vs. ignitor. Probably the checks in there will be helpful.