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ECU Types

Identifying Your PGM-Fi ECU


PGM-Fi ECU's have constantly evolved over the years, and can be separated into a number of categories.

  • Pre-OBD
  • OBD-0
  • OBD-0 VTEC
  • OBD-1
  • OBD-2

Inital identification of the ECU is by connector type, and looking for the model code on the casing.


Connector Types


Pre-OBD, OBD-0 and OBD-0 VTEC

From the very first PGM-Fi ECU in 1985 to around 1990. Early VTEC engines around 1990-1991 used a variation on the OBD-0 system, hence the term OBD-0 VTEC is used. 



Fitted to cars around 1991-1995



Fitted to cars around 1995-2000


Please note that there are more than a few exceptions to the "rules" above, Honda makes such a vast array of engines (and are in fact the world's largest manufacturer of engines) for many different parts of the world, with differing emissions standards, requirements etc. This is just a broad outline of what to look for.

The majority of ECU's fall into these categories, and Honda generally appear to design an ECU, make the odd modification to it throughout it's life and then use that final version as a base from which to create a new generation. Even the latest engines in 2006 can trace aspects of their configuration back to the very first PGM-Fi system in 1985 - this makes life for the Honda enthusiast very easy.

This is in stark contrast to the majority of other vehicle manufacturers that will use completely different management systems from a number of companies throughout the life of even one vehicle - an ABSOLUTE nightmare! The way Honda do it is undoubtedly due to the fact that Honda, are Honda and not a brand that's constantly bought and sold between various multinationals.


Part Code Label

The part code label, normally on the side of the ECU is the next thing to look at. Thankfully Honda again use a very logical system of identifying No matter if your ECU is from 1985 to 2005 the part code follows the same standard, which is as follows:

37820-xxx-xxx - for example:


The breakdown is as follows:

  • 37820 is the Honda part code for a PGM-Fi ECU. This immediately identifies the unit as the engine management system.
  • P30 is the ECU type, basically the configuration of engine it is designed to operate with.
  • G00 is the market to which the ECU is destined, and the revision number.

The ECU type could be one of the following - there are many, many types but here are a few examples.

  • P30 - OBD-1 1991 on Civic/CRX with B16 DOHC VTEC engine
  • P28 - OBD-1 1991 on Civic & variants with D series engines
  • PW0 -


The revision number can also be broken down further - for instance most Japanese ECU's are labelled 000, or sometimes J00. Honda being a Japanese based manufacturer obviously chose to give themselves a region of zero, in a similar what to which they label their engines. The first letter of the revision number is generally the country, or region. The following numbers are the revision number, showing minor changes have been made.

Here are some common examples of revision:

  • 000 - Japanese
  • J00 - Japanese
  • E00 - European
  • G00 - Great Britain


Under the Cover - The PCB

The next step is to remove the cover of the ECU.


Under the Cover - The ROM Number

One of the most important identifiers of any PGM-Fi ECU is the version of software it is running.