Honda OBD1 ECU Label Identification
A comprehensive guide to decoding Honda OBD1 ECU part numbers to identify engine compatibility, market origin, and transmission type.
Honda OBD1 ECU part numbers follow a standardized 37820-ABC-XYZ format. Understanding these identifiers allows for accurate identification of engine application, regional market, and internal hardware revisions.
Part Number Breakdown
The part number is structured as 37820-ABC-XYZ.
| Segment | Description |
|---|---|
| ABC | Engine/Chassis application code |
| X | Regional market code |
| Y | Transmission type (0: Manual, 5: Automatic) |
| Z | Board revision (Even: 11F0, Odd: 1720) |
Regional Market Codes
The middle character (X) of the suffix indicates the intended market for the ECU.
| Code | Market |
|---|---|
| A | USDM (49-state) |
| L | USDM (California Emissions) |
| J | JDM |
| G | EDM |
| Q | Australian Market |
| C | Canadian Market |
| N | Factory Reprogrammed / Service Unit |
Note
Some JDM units may use numerical prefixes (e.g., 9xx) to denote specific automatic transmission configurations.
Example Analysis: 37820-P28-A52
Using the breakdown above, the ECU 37820-P28-A52 is identified as follows:
- P28: SOHC VTEC (D16Z6) application.
- A: USDM 49-state market.
- 5: Automatic transmission.
- 2: 11F0 board revision.
Hardware Revisions
The final digit (Z) indicates the internal PCB architecture. This is critical when sourcing ECUs for socketing or hardware modifications.
- Even Numbers (e.g., 0, 2, 4): Typically utilize the 11F0 board architecture.
- Odd Numbers (e.g., 1, 3, 5): Typically utilize the 1720 board architecture.