I recently chipped my P28 ECU with Hondata S200B and now I have a solid check engine light. Does this mean the ECU is bad? How can I know for sure? And what exactly is bad in a "bad ECU"?

 

Ive got the same prob, I put a new "chipped" ecu in my del sol with the engine swap and now I got a solid cel, so far no one has given any help but maybe a bad chip or ecu, I'm sending back my ecu for another, hopefully that will work. Try checking your connections to the ecu, it didn't work for mine but it's easy to pull one of the prongs out of the plugs.

 

Well I took the car down to a Hondata tuner and he used one of his ECUs and it still throws the solid CEL so we know that my ECU isn't chipped wrong. He said that it's something that lies in the program itself, but my car runs fine. He made a few pulls on the dyno with no problems either.

 

you have a checksum error on the rom itself.

try putting a new rom burn in.