D16A to D15B ecu harness setup question.

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lordshelinator

New Member
I have the D15B ecu,p84, that I want to setup in place of a d16a ecu,p91. I have the D15B harness to run the engine. The question is, how do i integrate the new ecu wiring into the car's electrical and what should I be weary off. I have an EJ1 1995 si civic coupe.
 
Ok so let me get this straight... You want do install the P84 designed to run VTEC-E in place of the P91 designed to run SOHC VTEC? The P84 will give you a lower red-line and VTEC-E was used in a slightly different way; instead of optimising performance at high RPM, it was used to increase efficiency at low RPM. I would assume it's plug and play, but may I ask why? I'm assuming your EJ1 still has the Z6. From what I've read about the p84, I'd just run the P91 or P28. Somebody please correct me if I'm wrong.
 
Hey, thanks for the reply. My z6 needs to be worked on i.e. new pistons, decking, valve work. So all that will take some time. So I wanted to slip in the D15B while i do some stuff to the z6. My prob is I got the harness for the d15b engine, so the engine sensors are practically hooked up to the ecu. My question is the rest of the wiring that goes into the interior of the car. Is it as simple as following the color coded wire to work the p84 ecu into the ej1?
 
Ok, well there are around 10 D15's. If you're using an obd1 D15 (ie. B7, B8, Z1) it should all be plug and play. You shouldn't have to modify any interior harness unless you're going down to OBD0 in which case I'd just use a jumper harness. Either way, if you go ahead and modify your harness for this d15, it will all have to be reversed when you put your z6 back in.
 
I understand that it will have to be undone when the z6 goes back in., what I'm trying to get my head around is the wiring for the car it self i.e. the air condition sense,the ignition, ecu power, code light. Do I need to modify these if I'm just changing the engine. Let me see if I can clear up a few things. I have an EJ1 with D16z6 sohc v-tec with a p91 ecu. All of this is stock. I want to replace the z6 with a d15b sohc vtec-e with a p84 ecu in which I have the harness for but the harness has a few cut wires. Do I just search for the wires on the EJ1 and connect? Is it that simple?
 
I understand that it will have to be undone when the z6 goes back in., what I'm trying to get my head around is the wiring for the car it self i.e. the air condition sense,the ignition, ecu power, code light. Do I need to modify these if I'm just changing the engine. Let me see if I can clear up a few things. I have an EJ1 with D16z6 sohc v-tec with a p91 ecu. All of this is stock. I want to replace the z6 with a d15b sohc vtec-e with a p84 ecu in which I have the harness for but the harness has a few cut wires. Do I just search for the wires on the EJ1 and connect? Is it that simple?

there isnt a d15b vtec-e but just use the engine wiring harness from the z6
 
Yes there is. The D15 Vtec-E was found in the EG series vx models and some JDM EGs and even EKs. It has a 3 stage vtec and is intended to be more economical on fuel. But as he said, if you can use your Z6 harness, use it. But if it's a OBD2 motor, then you'll have to use a jumper and bring it down to obd1 if you'd like to avoid cutting and splicing.
An article worth reading:
D15B 1.5l SOHC VTEC
 
there isnt a d15b vtec-e but just use the engine wiring harness from the z6
No d15b vtec-e? Ghost engine I have, you say?lol
Unfortunately, there is one and the z6 harness only has three engine jacks where as the d15b has four. The d15b also has the 5 wire o2 sensor. So is it a matter of using the the z6 harness and wire in the o2 sensor? Murray thanks for the link and the info thus far, I have faith in thee to lead me right into honda heaven.lol
I will try to post some pics of the engine and the harness so this thread can help some other poor noob if I get the wiring done right.
 
Yes there is. The D15 Vtec-E was found in the EG series vx models
thats the d15z1. i dont think ive heard it referred to as a d15b. i know it as the z7. but anyway like he said just use your harness if you can and use a jumper harness if its obd2
 
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