S300 red light says on for 5 minutes before car will start

[Philipxhuff]

I just bought this civic with an all motor gsr and hondata s300. Almost every time I go to start the car the red light inside the ECM stays red for at least 3 minutes. If I leave the key in the running possition without trying to crank the engine after 3-5 minutes the red light goes off, the engine light goes off and the car fires up no problem. Any suggestions?

[Spunkster]

This sounds like a possible faulty capacitor in the ECU. Try replacing the main large capacitor in the ECU and see if that resolves the issue. Alternately you can just swap the s300 to a known working ECU and see if the problem is resolved. Then you know for sure it is the ECU that is the problem.

[Philipxhuff]

Thanks for the help! Any chance you know where I can get that capacitor and some instructions on how to replace it? I could google it but it sounds like something I probably shouldn't trust some random people online with.