I think your ecu is fine. This is a common problem (false error 20).. Next thing to check is your multifuntion relay (by replacing it). Third thing is to open up the bottom of your ignition, and clean the contacts in there (you'll need a small hack saw to cut in slots in the bolt heads so you can use a screwdriver to turn them).
Also give a little history on how the issue started. Might help diagnosis.
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