Thread: B15 to B13 stepdown harness??

Its this possible or can be done without any major issues??
I have all the parts necessary to do it any input are welcome..
And I wont need any emission stuff or OBDII working..

its possible and has been done before. Might try searching b15sentra for the information.

Should be a simple set-up. Alot less work then making a B15 to B14 harness. With going OBD1, there will be alot less pins to connect.

I just made my second B15 to B14 conversion harness. Here is my thread. You might find some useful B15 related in it. I highlighted a couple of areas in the below links!

http://www.sr20-forum.com/tuning/49938-tuning-my-calum-r-t-2.html

http://www.sr20-forum.com/tuning/49938-tuning-my-calum-r-t-7.html#post708598

Here is a spreadsheet with most of the B13, B14, B15 ECU pinouts and a cross refernce of all of them as well. (Courtesy of "The Russian")

https://docs.google.com/spreadsheet/ccc?authkey=CMWMt_gN&key=0Anmiu0rUufw3dDAzRzlFUDRGWkRLMV9Sc3lFWHpxQ2c&hl=en_US&authkey=CMWMt_gN#gid=0


Hint: When you are sealing up your connections on the B15 plug side, don't use epoxy. It is permanent and makes a bloody mess if you are not careful. Get yourself a glue gun, buy some extra strength glue sticks and use that. It is much easier to work with, hardens in minutes and can be undone with a little bit of heat, if you make a mistake!!





Edit: Payu, I found this on b15sentra.net. Credit should go to Trav4011 for the write-up.

B13 to B15 ECU wiring harness conversion - B15sentra.net - Nissan Sentra Forum

I saw that thread but thats its to connect a b13 ECU harness into a B15 sentra..

It's not too hard, but it's definitely an involved process. Here my notes of making a P11 to B13 step down:
http://www.sr20-forum.com/howtos/47198-how-modify-00-p11-b15s-work-older-ecus.html

Also on B15's you might have to run an extra wire to the distributor, B15NEOVVL can tell you all about that one

When I linked that thread, I actually had a few different pages open on my browser and I copied and pasted the wrong one. :o I didn't read the one I posted to be honest. Unfortunately I can't find the other thread now.

Honestly though, if you have the necessary parts and you read the link that Vadim posted along with the B13, B14, B15 pin-out spreadsheet that I posted, you will be fine.

Like Vadim said, when I did made my step-down harness I had to run an extra wire from the distributor directly to the ECU, as my B15 dizzy did not have the 2nd wire on the ignition coil harness (2 prong plug) for 'ignition check'. It is pin # 36 on the B15 ECU/wire harness. My dizzy only had ignition signal pin # 35. Here is a picture:




Maybe you are lucky and you will have this wire on your dizzy. If you don't you can use a plug off of a '99-02 G20 dizzy as it shares the same plug as the b15 harness At that point you would just have to run a wire directly to the wire that comes off of pin #3 on the B13 ECU. Here is what I had to do, just incase you are in the same situation:

http://www.sr20-forum.com/tuning/49938-tuning-my-calum-r-t-2.html#post680339

And here is a picture of the extra connection I made for my missing 'ignition check' wire. I then made a connection and ran the wire directly to the distributor.





Coaltion SE-L also has a nice write-up on making a conversion harness on the old forum, which I am sure you have already seen as you are a member there.

I am not sure if you would even need my help, but if you have any B15 related questions I would be glad to help!

Cool guys thanks for the help I am waiting on my b15 ecu to arrive after that I will start with this...

Mission accomplished I tested it yesterday was a complete success thanks for all the Info...