Symptoms of a failing Ignition Control Module?

[gillmore]

This week, while two hours from home, my Ignition Control Module (ICM) failed while on the freeway heading toward the vicinity of Yosemite. I got towed to a shop and all is better now, but I'm wondering if there are signs that an ICM is going bad or if it is a works-or-doesn't type of part? Were there signs I perhaps didn't notice?

Is there an easy way to diagnose (or rule out) an ICM failure myself if this happens again?

Thanks in advance.

 

[Old Dog]

From my experence they either work or they don't.
I carry a spare at all times now.

 

[LongHorn]

This week, while two hours from home, my Ignition Control Module (ICM) failed while on the freeway heading toward the vicinity of Yosemite. I got towed to a shop and all is better now, but I'm wondering if there are signs that an ICM is going bad or if it is a works-or-doesn't type of part? Were there signs I perhaps didn't notice?

Is there an easy way to diagnose (or rule out) an ICM failure myself if this happens again?

Thanks in advance.

That's one of the first items I remove from a 76'-86' CJ.
Most of the time there's no sign of a problem other than you rig won't start.
I was out trail running & stepped my front right tire over a big rock.
when I came off there was a little bounce , but no big deal.
Wrong the engine died never to start, until I snapped on a new module.
Use to you could not even test the Motorcraft module, I don't know about nowdays It's been so long since I've run the factory set up.
Now I run a HEI & keep a spare module in my box.
Back in the day a CJ module was about $120.00, of coarse now they are much cheaper.