Frequently Asked Question

Honda ECU Label Decode

Last Updated 4 years ago

You can find out a lot from reading the label on an OBD1 ECU. This applies mainly to the Civic ECU

37820-ABC-XYZ

Digits	Meaning
ABC	Engine ECU designed for
X	The market of ECU - see chart below
Y	0: 5-speed, 5: Auto
Z	even number: "11F0" board, odd number: "1720" board

Code	Market
Axx	USDM 49-state
Lxx	USDM Cali Emissions
xxx	JDM
Jxx	JDM
9xx	JDM (auto)
Gxx	EDM
Qxx	Oz DM
Cxx	Canadian
Nxx	usually, factory reprogrammed, no particular market

Example:

37820-P28-A52