This is a simple DIY for people who want/need to convert their own automatic ecu into a manual instead of buying a new one. I highly recommend that you get some soldering/desoldering practice before attempting it by yourself.

List of things you need:

obd1 automatic ecu


Philips Screw driver


Soldering pin


desoldering braid


soldering wire


Wire cutter


Carb cleaner; The carb cleaner is used to clean off the clear coat that Honda used to protect the circuit boards. You can either use a tooth brush and brush off the clear coat before you start doing any sort of soldering or you can use it to clean it off afterwards. I however did not have any with me at the time so please forgive the sloppyness of the clear coat burns.

Any ohm resistor since you'll be cutting off the end pieces to use.


First and most simple get your ecu and take off both back and front covers:


On the front side locate RP17 and RP18:


Once you have located them turn it to the backside and get your soldering pin and desoldering wire. I usually like to heat up the desoldering braid to make things easier:


Again locating RP18 and RP17 on the back of the board start desoldering the resistors out. " You could either cut them out first and then desolder it or desolder it first and then pull them out" I however chose to desolder them both before pulling anything out.


This is how it should look like once you have desoldered it:

Do this to all the connecting spots in order to take the resistors out.

Now that you have desoldered all the connecting spots you should be able to pull them out easily with your wire cutters or pliers:




Now we will fill up the holes for RP17 "If you chose to cut the resistors out before desoldering than you can skip this step. Here is a pic of RP17 filled:


Now take your resistor and cut off one of the end wires to use for RP18:


Take that piece and bend it into a U shape for easy insertion into the ecu "RP18":


Once you have inserted it into RP18, turn the ecu over and bend the wires so that it stays in place. This also makes the soldering much easier:


Now solder it in. Should look like this:


Then take your wire cutters and cut off the extra ends that are sticking out:


This is how it should look like once you do everything:


Once you are done make sure you double check to see that all soldering joints looks nice and clean. When you plug in the ecu into the car make the the battery is disconnected before doing so. I hope this will help out others who are in need of it. Goodluck!!!!!!!!!!!

 

Thanks a lot! This is great and it should be very helpful to everyone out there seeking help on this conversion.
two thumbs up to you man!

 

Thanks, I hope it helped with your situation.

 

Nice

 

saved to .doc


Thank you

 

What size resistor did you use when you cut the one end of it off for RP18?

 

Just finished my onversion and all IS good! Thanks again Mouab18c1!

 

There is no resistor needed. Just cut off a leg from one of your resistors and use that.

You're welcome

 

its just a jumper needed for rp18

ive never cleaned the board before and just cleared away any solder after

i put the ecu between 2 books and just melted the back then pulled the resistor with a needle nose pliers, then if it wasnt clean enough, just sucked out the solder

but thats just me. good write up though

 

Cleaning the clear coat off just makes it look better. It also makes it easier to solder.

 

So I need some input. I am trying to verify if my ECU is auto or manual. It is a OBD1 PR3 from a JDM Integra XSI. The ECI # is 37820-PR3-J51, which decodes as an automatic from everything I have seen. However, there is NO resistor on RP17, and it looks like it came that way from the factory.

 

Bump, nice write up

 

Cool will this guide apply to the P12 ECU in the 92' 96' prelude?

 

Bump. Nice thread. My question is will this go with all obd1 ecu? For example p06?

 

I believe so, yes...

I have a question though, my ECU was chipped in the past and the guy who sold me it didn't know anything about it. It has the rp17 and rp18 resistors on the board, am I right to think if it has these resistors it was an auto ecu?

 

bump cause no one answered my question

 

yes, if it has them then it is/was auto

 

Nice

 

could you just use a paper clip for the jumper? I mean it works for everything else to jump.

 

Nice.

 

I kno this is an old thread but will this work for an OBD2B auto?? I jus converted my 2001 integra to manual and was wondering if this also applied to it as well. Help!!

 

No this will only work for obd1 ecu's.

 

This is the same issue I have with my 1994 DB7 LS.
I just did the auto to manual transmission swap but the car ECU number is 37820-p75-y51 and after I opened it to check for the RP17 and RP18, both are missing.
Does anybody have a clue if by those 2 resistors not found on the ECU will represent no problem at all when driving?
My Integra ECU is 37820-P75-Y51.
As I wrote, it has no RP17 and RP18.
Does anybody knows how wich resistors have to go and where to bridge?