I was able to find a 15 code (IGNITION OUTPUT) on my 90 Honda Civic. It will start & run for awhile then the CEL, OIL, & BATTERY lights come on & it dies. It you let it sit 10 minutes it will start & run a little farther.
MY QUESTION???
Could this be a Main Relay? If not what would be next to look at??
Any help would be appreciated I'm in a tough situation & need to get this going because my wife has a 132 mile a day round trip to work.
HELP.
Thanks in advance.

 

I think that is an internal ECU failure, one of those rare cases where it is necessary to replace the ECU. Bad ICMs are famous for running a while then die and won't restart until cooled off, but I don't think any code is set then.

The main relay is connected to the fuel system. The ignition is separate.

 

How can I go about figuring it out or confirming what it is without throwing money at it. The closest shop that has any experience with Honda is 75 miles away.
Thanks

 

After some further research It appears that Code 15 is common with the ICM as you stated. So that is a $50 part so I think I will go that route & see.
Thanks