Acura Legend Forum banner
1 - 20 of 34 Posts

·
One Meeelion HP
Joined
·
2,907 Posts
If you have any information to add or ROM files, please dont hesitate to post!

Lets first describe the part numbers:

Example:
37820-PY3-A52
37820-PX9-A17

37820-PY3-A52
It is an ECU Part Number
37820 = Honda's part number for any engine computer. We can ignore this number.

37820-PY3-A52
Engine Code
PY3 = Type I Engine Code
PX9 = Type II Engine Code
PR7 = NSX Engine Code

37820-PY3-A52
Region Code
A = U.S. Federal Emmissions
L = U.S. California Emmissions
C = Canadian
G = European
J = Japanese

37820-PY3-A52
Transmission Type
0 = Manual Transmission, Type I or II
1 = Manual Transmission, Type II with TCS
5 = Automatic Transmission, Type I or II
6 = Automatic Transmission, Type II with TCS
7 = Automatic Transmission, Type I, Revised shift maps

37820-PY3-A52
Revision Code
This number goes up with the software revision, the later model cars usually use a higher number.
For the most part, it seems that sedans use a EVEN revision number (A52) and Coupes use an ODD revision number (A53).

--------------------------------------------------------------------

There are two main generations of ECU's:
The Gen "A", 1991-1992 Model Years, MCU Code "28", Board Number "E-2281A"
The Gen "B", 1993-1995 Model Years, MCU Code "3E", Board Number "E-2413A"
The Gen "C", 1993 Model Year, MCU Code "36", Board Number "E-2413A"

The differences between the E-2281A and E-2413A boards is slight. There is a slight difference in component layout, and component usage. The newer E-2413A boards have an onboard LED for diagnosing internal problems with the ECU, also they have a 5 Pin diagnostic header "CN400".

A quick way to tell if you have a 1993-1995 (gen C or B) ECU is to check the top cover. It will have a cut-out with a plastic window on the top connector side. The newer ECU's have an LED on board that lights whenever a critical internal problem with the ECU is present. The LED is visible through this window.

Since all of the circuitry in the board is the same, any Gen "A" ROM chip can be run on any Gen "A" ECU. For instance, if you have a PY3-A55 ECU, you can run a PY3-A52 ROM Chip, A PY3-J03 Japanese Rom Chip, a PY3-G52 European Rom Chip, etc.

Since all of the circuitry in the board is the same, any Gen "B" ROM chip can be run on any Gen "B" ECU. For instance, if you have a Type I PY3-A58 ECU, you can run a PX9-A17 Type II ROM Chip, a PY3-A72 Type I ROM chip, A PX9-A58 Type II ROM chip, etc.

This information is great for upgrading your ECU from a type I to Type II and other uprades which will be announced in the near future.

----------------------------------------------------------------------
Automatic Transmissions

There are 2 different board designs:

The 1991-1992 Model Years, Board Number "E-2286C"
The 1993-1995 Model Years, Board Number "E-2414A"

From the Japanese JDM Factbook side the 1993-1995 Automatic Transmissions have a slightly different internal design. Also, the 93-95 have a fuzzy logic shifting program called "PROSMATEC" that improves 3-4 and 4-3 shift hunting.

From my experience with upgrading to the PY3-A72 (GEN B) ECU in my 1991 Coupe, the transmission shifting is extraordinarily better. The shifts are smoother and more refined, it gives the car a whole different feel.
----------------------------------------------------------------------
Converting an Auto Trans ECU into a Manual Trans ECU

This is very simple. Just get a pair of sharp snippers and cut this resistor off:



Then cut or de-solder the ribbon cable to the Auto Transmission daughterboard and you have a manual transmission ECU. I would recommend some type of plug to seal the hole left by the daughterboard, or just re-install the disconnected daughterboard.

----------------------------------------------------------------------
Converting a California Emmissions ECU into A Federal Emmissions ECU

Locate the blank resistor pad, R411 on the circuit board, circled in red:



Solder in a 1% Tolerance 1K Ohm Resistor. Color code: Brown - Black - Black - Brown. Tolerance 1% - Brown

----------------------------------------------------------------------
Traction Control

Traction control is a HARDWARE option that can be added to ANY ECU, be it Gen "A" or Gen "B". There are a handful of components that have to be soldered in place so that the ECU can communicate with the traction control system. For the JDM market, TCS was optional for the 1991 and 1992 model Legends. Therefore, there is an option spot on all Gen "A" Models.

----------------------------------------------------------------------
Gen A ECU'S (1991-1992)

PY3-A52 USDM Type I, Automatic, Sedan
PY3-A53 USDM Type I, Automatic, Coupe
PY3-A54 USDM Type I, Automatic, Sedan *rare*
PY3-A55 USDM Type I, Automatic, Coupe

PY3-A02 USDM Type I, Manual, Sedan
Py3-A03 USDM Type I, Manual, Coupe

Regions:
PY3-C52 Canadian, Type I Automatic, Sedan
PY3-L52 USDM, California Emmissions, Automatic, Sedan
PY3-G52 European, Automatic, Sedan
PY3-J03 Japanese, Automatic, Sedan

Gen B ECU's (1993-1995)

PY3-A72 USDM, Type I, Automatic, Sedan

PX9-A67 USDM, Type II, Automatic, Coupe, With TCS
PX9-L67 UDDM, California Emmissions, Type II, Automatic, Coupe

PX9-A17 USDM, Type II, Manual, Coupe, With TCS

Gen C ECU's
PY3-A06 USDM, TYPE I, Manual, Sedan
PY3-A57 USDM, Type I, Automatic, Sedan
PY3-A58 USDM, Type I, Automatic, Sedan
PX9-A04 USDM, TYPE II, Manual, Coupe, NON-TCS
PX9-A15 USDM, TYPE II, Manual, Coupe, TCS

more later
 

·
Keeper of Keys
Joined
·
587 Posts
good post, ya i wanted to know the numbers represented on top.. I have 2 ecus now, Orginal one L series and a A55 thats chiped, When i go in for smog i switch ecus, and pass with flying covers, i really don't want to try it with the other, i think i will pass but i can smell im brining rich with the chiped :) 75 bucks by the way each time in cali to get yourself smoged ....sucks.. dv8 has alot of exp with this im sure :)
 

·
Registered
Joined
·
4,037 Posts
okay some info and confusion..

I have a py3-A55 that i am sure came out of a type 1 sedan.


I also have a Py3- A04 that came out of my 5spd coupe(type 1 92)

Then my ECU i am currently running with a chip is out of a 94 coupe that is i believe a px9-A55(57?).


Anyways i am missing an ECU i realized i think...lol.

Ps-Just curious if some of the code was used for sedans and coupes etc etc...

***Also one or two cars i have seen were 93 type 2 WITHOUT TCS.....so that might lead to some of the ECU code crossing.

BEN
 

·
Registered
Joined
·
4,657 Posts
Okay here's one for you (this is my original stock ECU, extra,i took out, I have a Fed Bayou chipped one in there right now)

'95 Legend Auto TypeII California No TCS (L model)
37820-PX9-L57

Why "7" ? It's the stock ECU...
 

·
One Meeelion HP
Joined
·
2,907 Posts
Discussion Starter · #7 ·
Okay here's one for you (this is my original stock ECU, extra,i took out, I have a Fed Bayou chipped one in there right now)

'95 Legend Auto TypeII California No TCS (L model)
37820-PX9-L57

Why "7" ? It's the stock ECU...
"7" is the revision number, I'm not 100% sure on what the specifics are, but but it seems that with MOST cars the even numbers are for sedans and the odd numbers are for coupes.

-Matt
 

·
One Meeelion HP
Joined
·
2,907 Posts
Discussion Starter · #8 ·
Would you mind doing me a favor if you can pull off the cover and set the transmission board aside? look at the large square IC in this picture:

http://users.adelphia.net/~sr5guy/forum/Automatic.JPG

the number "YEAMH3532728" can you get me the last two digits off of yours please?

It should be "28", "36", or "3E".

This identifies the code the ECU uses.

Thanks,
Matt
 

·
Registered
Joined
·
1,033 Posts
37820-PY3-A52
Region Code
A = U.S. Federal Emmissions
L = U.S. California Emmissions
C = Canadian
G = European
J = Japanese
Odd... because my Legend is an "A17" meaning "U.S. Federal Emissions" and not a "C" for Canadian. My Legend is defeintely a Canadian model since the gauge cluster was all metric and it had factory DRL (Daytime Running Lights). Perhaps they had a code for Canadian, but ended up just using an "A" code instead for Canadian made Legends?
 

·
Registered
Joined
·
420 Posts
Hmm... Has anyone ever seen a "Cxx" ECU? I've never heard of one, so maybe the Canadian Legends all had US Fed ECUs.

Just a thought...

Mike
 

·
One Meeelion HP
Joined
·
2,907 Posts
Discussion Starter · #12 ·
Actually, I got the "C" information from a link on this board - in the beavedit thread...

http://other.ditcorp.com/be2/PY3-C52.bin PY3 - C52 Legend Type1 Automatic CANADA

The code is the same as the federal PY3-A52, I think the difference is in the automatic transmission daughterboard - the Canadian models have different gearing. Thats probably why the Manual transmission ECU has the same part number as USDM.

-Matt
 

·
Registered
Joined
·
4,037 Posts
mmmm how is the canadian gearing different ;)

i am in the import export business.....hahaha
 

·
Registered
Joined
·
4,990 Posts
May wanna add the PY3-L02 1991 California 5speed manual Chip
 

·
Soon to be BOOSTED!
Joined
·
2,594 Posts

·
Soon to be BOOSTED!
Joined
·
2,594 Posts
I'm not sure to be honest. I bought it off ebay. The guy said it was a federal, automatic transmission, non TCS Type II ECU.
 

·
Soon to be BOOSTED!
Joined
·
2,594 Posts
You have this posted on the first page ...PX9-A67 USDM, Type II, Automatic, Coupe, With TCS

However I just pulled an ECU from a 94 GS Sedan and the model #on the ECU reads PX9-A67

Sow that would go against your theory of all coupes having the odd number. I dont think anybody will know for sure what ECU is specifically fmade for any specific model other than being able to tell if its a Type II or Type I with or with out TCS.


My next question is what ECU would be better to have, the PX9-A57 or the PX9-A67? I was told the A57 does not have TCS.

Thanks for your help.
 

·
One Meeelion HP
Joined
·
2,907 Posts
Discussion Starter · #20 ·
You have this posted on the first page ...PX9-A67 USDM, Type II, Automatic, Coupe, With TCS

However I just pulled an ECU from a 94 GS Sedan and the model #on the ECU reads PX9-A67

Sow that would go against your theory of all coupes having the odd number. I dont think anybody will know for sure what ECU is specifically fmade for any specific model other than being able to tell if its a Type II or Type I with or with out TCS.

My next question is what ECU would be better to have, the PX9-A57 or the PX9-A67? I was told the A57 does not have TCS.

Thanks for your help.
Yeah that theory is done. I just pulled a PY3-A52 ECU out of a coupe. Maybe its L/LS model? All of the other information is verified correct. Thats why I stated that the Odd/Even numbers was THEORY.

5=Non TCS Auto ECU
6=TCS Auto ECU

-Matt
 
1 - 20 of 34 Posts
Top