super china china

Ok so one thing ive heard a lot since ive gotten into Hondas but have never really understood- OBDI and OBDII and what not.

Could somebody explain to me exactly what they are, what the difference is, how you know what you have, when it is called for converting, etc? Ive searched all over but havent found anything.

So if someone could please give me a link to someplace explaining it or just explain it that would be great. Thanks

hatchling37

On Board Diagnostics. It's a system to ensure that all operating systems are working as they're intended to. I and II are, in a very generic matter, are "versions", i.e. v. 1.0 as opposed to v. 1.1. Easy way to tell is the year. Pre-'92 is OBD0, '92-'95 is OBD I and '96 and up is OBD II or greater.

super china china

Oh ok i see. Thank you sir

starbai

thats it? so whats all the fuss between deciding whether to switch between OBD I and OBDII when building motors and tuning them for turbo etc... ?

I'm trying to search before asking stupid questions but I can't seem to find any details on the pros and cons of each etc...

can anyone link me to a good FAQ or resource explaining it all?

starbai

anyone? anyone?

nextproject97

OBDI is more tunable

Scott_Tucker

They are definitely easier to reverse engineer and I think that is the biggest reason for it's popularity. It all depends on the ECU but map size in most OBDI systems is smaller than in OBDII, so I don't think 'tuneable' is necessarily the correct term.

starbai

so when you see guys that have PC's like permanently hooked up to thier computer where they can select different tuning settings on the fly... what is that? just the type of ECU management? and would that type of managmeent be compatible with both OBDII or OBDI?

If it sounds like i have no idea what i'm talking about, its cuz i dont. But i'm trying to get a good grasp and learn here so please take it easy on me. if i understood enough to know what to search for, I'd gladly do that rather than ask a dumb question.

xander1100

the laptops hooked up to th ECUs is for like crome, etc

starbai

and ecu's that can hook up to this kind of thing are generally both OBD1 and OBD2 compatible?

GhostAccord

Haven't seen too many OBD2 ECU's hooked up to Crome, it's an OBD1 only ROM editor. Although there are a select few people who can chip and tune obd2 ECUs. But from what I know about chipping OBD2, it's not practical. The fine tuning options just aren't there for the OBSD2 ECU. And there really isn't much software/tuning support out for OBD2 vs OBD1. Hondata does have the K-Pro OBD2 system but I believe it is strictly for 02-04 RSX and 01-06 JDM ITR ECU's.....

Most of the people that you see hooking up there laptops to there ECUs will be using chipped OBD1 ECUs (P06, P28, P72, P75..etc..etc) or a stand alone Engine Management System (EMS) like AEM or Motec.

starbai

awesome, thats pretty much what i needed to know, i think.


thanks!

Episode

i have to revive this, sorry. when speaking of ECUs, there are different types. P06, P28, P72, P75..etc, i'm assuming these are the different ECUs that came out of different vehicles.

when doing a swap, or simply looking to tune your stock motor, how would you go about selecting an ECU? why would someone pick a P28 over a P72?

also, correct me if i'm wrong: chipping your ECU just means you've burned a new ROM chip and kind of replaced the old one in the ECU, right, or completely wrong?

i'm sort of in the same, clueless boat as the OP...

EDIT: nevermind, i found this nifty site http://www.sportcompactcarweb.com/te...ine/index.html

it answers a lot of questions as you read through it. i suggest this read for anyone with any interest in honda motor swaps.

starbai

awesome! thanks for the article!

super china china

I feel like ive learned a lot. Thank you very much guys!