I am in the process of sourcing a replacement ECU for my 1991 crx dx 5spd. I am having trouble getting a straight answer about the interchange. My current ecu number is 37820 pm5 a30. Will any ecu for 90-91 civics with the "pm5" ecu work? Does the last 3 charactors really mean anything besause the revision of that particular ecu? Does it matter if it is an automatice or manaul tranny ecu?

 

the last three characters do mean something - ECUs with A## were for everything except cars originally sold in Calif - Calif cars have L## - the numbers can indicate whether it is manual or automatic - running the automatic ECU in the manual car will trigger a Check Engine Light with a code 19 for the lock-up control solenoid valve on the automatic transmission

 

thank you, so my numbers must match