I have a 1991 Civic Si. It was running fine for m onths, then in the last days of its life it stalled a couple times while driving it and wouldn't start sparatically. Well One day I started it up and moved it into my driveway and then it would not start after that. I noticed some dry cracks on my main relay and resolder them.. That didn't work.. I then remembered before it died the check engine light would come once after driving it for awhile sometimes. I checked the code and it was code 15. So I figured it must be the ICM.. I changed it and on my first try it started up with out a hiccup. I let it run for a little and shut it off and went back into the house.. Well the next day I tried to start it and it is NOT starting again. Could the ICM be burt out again? What other issue can it be? I am getting frustrated. Thanks for any help!

Make sure you applied silicone heat-transfer compound to the back of the new ICM. I'd recommend that you replace the coil, also. Here's how to properly do the work:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-4.html#post265896

Ya ill try the coil as well. I just think its very very odd it started up right after I changed my ICM and now its dead in the water again..

Run the tests in Sections 1 and 2 of the Sticky.

Ya I printed the test out and will try them tonight. Thanks again for your response. I was so happy the other night when I fixed it and now its back to where I started. Its been a learning experience which will help me in the long run though.

Yes. Then you'll be in a better position to help others, too.

Code 15 is definitely ICM-related. Be sure to reset the ECM by removing the 7.5A Backup Fuse, in the under hood fuse box, for 10 seconds.