I have 2 ECUs that came with a car I bought. One is a PR3 and the other is a P30. They look just like all the other OBDI computers I have seen and have 3 plugs in places. Do OBD0 ecus have less plug in spots than OBD1 ecus? I ask this because I searched around and it seems like OBD0 was the only way they both came. If they are OBD1 does that make them more valuable? I ask because I was thinking about selling them but I am not sure what to ask for them and I don't want to them OBD0 if they are OBD1.

The Pr3 has also been chipped and socketed.

 

Here you go:

Identifying your ECU

To identify your ECU you will need to know its generation, part number and possibly its ROM number.

The ECU can be located in several places: under a metal plate in the passenger's footwell (models up to 91), in the passenger's footwell behind a plastic panel (models 92-99) or by the driver's footwell under a plastic panel (some models 2000+)

The computer is connected via three connectors that pull out when a plastic clip is pressed. Remove the computer, and with a philips screwdriver remove the metal lid from the top of the computer. There may be small daughter circuit board covering some of the main circuitry. Unscrew this and lift it out of the way.
ECU Generations

Honda ECUs run in generations, which use different connectors. Below is a stack of ECUs running from the newest generation at the top to the oldest generation at the bottom.

OBD2B (left 3 plugs used)

OBD2A ECU


OBD1 ECU


OBD0 (JDM PR3 and PWO)

ECU Part Numbers

All Honda ECUs have a part number which is located on the side of the ECU and inside the ECU on the connector. e.g. 37820-P72-A01

The part number consists of three components:

* Honda's part number for ECU, which is always 37820
* Three characters (which are loosely related to the model of car/engine). e.g P72
* Three characters (which are the revision of the ECU) e.g. A01

The middle three characters are the most useful to identify what the ECU is. Different generation ECUs may use the same characters. e.g. a P72 OBD I ECU is different from a P72 OBD II ECU. Here is a list of common ECUs:

* PG7 : 86-89 Integra (86-87 vac advance, 88-89 electronic advance)
* PM5 : 88-91 Civic/CRX DX
* PM6 : 88-91 Civic/CRX SOHC Si
* PM7 : 89-91 DOHC ZC (JDM 'EF' ECU)
* PM8 : 88-91 CRX HF
* PR2 : 89-91 ZC (Euro)
* PR3 : 89-91 JDM B16A EF8/9
* PR3 -J00 or J51 : 92 JDM Integra B16A EF8/9
* PW0 : 89-91 JDM B16A EF8/9 DA6-XSi
* PR4 : 90-91 Integra LS/GS
* PS9 : 88-91 4 door Civic EX Auto
* P05 : 92-95 OBD-1 Civic CX
* P06 : 92-95 OBD-1 Civic DX
* P07 : 92-95 OBD-1 Civic VX
* P08 : 92-95 OBD-1 Civic D15 JDM
* P0A : 94-95 OBD-1 Accord EX
* P13 : 93-95 OBD-1 Prelude Vtec
* P14 : 93-95 OBD-1 Prelude Si (non Vtec)
* P27 : 92-95 OBD-1 EG JDM Civic 1600 sohc
* P28 : 92-95 OBD-1 Civic Si/Ex
* P30 : 92-95 OBD-1 DelSol DOHC Vtec Si/EG SiR
* P54-G31 : 1997 Honda Accord 1.8 LS
* P61 : 92-93 OBD-1 Integra GSR
* P72 : 94-95 OBD-1 Integra GSR
* P72 : 96-00 OBD-2 Integra GSR
* P73 : 96-00 OBD-2 Integra Type-R (JDM & USDM)
* P74/75: 92-95 OBD-1 Integra LS/GS
* P75 : 96-00 OBD-2 Integra LS/GS
* P2N : 96+ OBD-2 Civic HX Coupe
* P2P : 96+ OBD-2 Civic EX Coupe
* P2E : 96+ OBD-2 Civic DX Coupe
* P2M : 96+ OBD-2 NZ Civic SOHC VTEC
* P2T : 99+ OBD-? Civic Si Coupe
* P5P : 97-00 OBD-2 Prelude Type-S (JDM ECU)
* PBA : 97+ US Acura 1.6EL
* PCT : 98+ JDM ITR / CTR
* PCX : 99+ OBD-? S2000

ECU ROM Numbers

As further identification Honda ECUs have a software revision number inside the ECU. This is usually a two or three digit number stamped on the 28 pin ROM, or main processor. Accord and Prelude ECUs can use a letter and number code.

 

Thanks for the info but I already came across it and read it. I know what the ECUs are I just don't know if they are OBDI or OBD0.

 

using the list above tells you what obd they are...
pre92 is obd0
92-95 is obd1
96-98 is obd2a
99+ is obd2b

p30 are obd1 and obd2 (though the latter are quite rare)

 

The P30 is definitly an OBD1, I am just not sure about the PR3. It is a PR3-J01 and has the same type of connections for the wiring harness as the P30. Am I correct to assume that the OBD0 has a different style connector where the harness meets the ECU than the OBD1 stuff?