Engine Harness Rewire W/ Hard To Find Pinouts
01-20-2014, 02:06 PM
#1
Engine Harness Rewire W/ Hard To Find Pinouts
Sorry, I'm bad at the uploading picture thing, mods, please fix at your pleasure... lol... anyways
Hey guys. I blew my motor a few months ago and been cleaning things up since my motor is out. So I decided to rewire my engine harness to clean it up some. Also, more important if you plan to do this yourself, is the C101 pin out and terminal block pin out incorporated in the engine harness. Also a schematic of ecu logic grounds and wire shielding grounding.
To start, I bought expanding non split wire sleeveing from cable ties and more website.
http://www.cabletiesandmore.com/ExpandableSleeving.php
You need a hot knife to cut the stuff, if you don't, the ends will fray. Also need shrink wrap to melt at the ends to keep it from fraying and clean. Bought my shrink wrap from harbor freight along with the hot knife. I used the marine heat shrink because the glue sticks well to the wire wrap and holds tight. You use the 2 smaller sizes the most, I went through probably 2 and a half cases of the smaller sizes. that's with cutting them into 1/4's and halves for different spots. Also got my de-pinning tools from there. I use 2 different one. A thicker one for actual sensor connecter and a smaller one for ecu de-pinning. I use the straight ones from each of these kits
ecu de-pinning tool - http://www.harborfreight.com/5-piece...-set-1816.html
sensor de-pinning tool - http://www.harborfreight.com/4-piece...set-66836.html
hot knife - http://www.harborfreight.com/130-wat...ife-60313.html
marina shrink wrap - http://www.harborfreight.com/42-piec...ing-67598.html
You pretty much put the wrap around the wiring, slide the shrink wrap over and use a heat gun to shrink the tubing. Be careful, cause the sleeveing will melt also if you point it towards it for more than a second, you have to keep the gun moving around the shrink tubing to shrink it but not long enough to melt the sleeving. Practice first so u don't have to undo your first one like I had too, lol...
But you gotta route the wiring however you wanna do it. The possibilities are endless on routes you can go. You can hide everything the most you can or do what I did, just make the harness look better and still be user friendly for working on the engine. Its all up to you and what you want.
Here are my pics from before till after. Remember to keep some slack on the #1 coil wiring cause if you already have or plan to get a standalone ecu and possibly certain instances with the stock ecu, you will want to be able to get a timing light ring around the #1 coil wiring to check timing or sync timing with ems's.
[attachment=52486:image.jpg]
[attachment=52487:image.jpg]
[attachment=52488:image.jpg]
[attachment=52489:image.jpg]
[attachment=52490:image.jpg]
[attachment=52491:image.jpg]
[attachment=52492:image.jpg]
[attachment=52493:image.jpg]
Now I searched quite a bit to find a good engine harness to chassis connector pinout. That's the blue and white connector at the end of the engine harness often referred to as the C101 connector. Do not mess this connector up as there is no aftermarket version. You can only get it from another engine harness or possibly from the dealership. But the white pieces fold up then you take them off and de-pin it from the top and bottom by pushing in the middle of the connector. I'll have to get pictures as I didn't get any. anyways, for the pin out, I made one for our s2ki community. I also made one of the blue terminal block that's wrapped up with the engine harness and the logic grounding for the ecu/engine harness. I made these because you will not find them anywhere. possibly the C101, but not for the main sensor logic grounding and the terminal block. I have a service manual and its not in it. you can use the service manual for everything else like wire colors/sensors/ecu pinout/etc, but not for what I'm about show you.
So, The C101 Connector Pin Out. Pretty self explanatory. The places that say "Engine Harness Terminal #" is the blue terminal that's in the next pin out. Again, the C101 connector is at the end of the engine harness and connects to the chassis harness by the ecu connectors.
[attachment=52494:image.jpg]
Next is the blue terminal junction box that's integrated by the end of the engine harness, its wrapped up in black tape and most of you probably never even seen it before if you've never unloomed the harness before. All it is is a junction box of 12vdc power and ground. T1 (terminal 1) through T6 is power source for injectors 1-4 and the IACV and getting power from the C101 connector pin 1 (or C101-1). So, you can mix match any of these terminals a get the same results. I have three OEM harnesses and they are all different. The main sources are always the same (T1 for injectors, and T11 for coils), but any order will work for T1-T6; T8-T10; T11-T15; and T17-T20. If you take the top of the terminal off, you will see a bar of male connectors and splits where it does and does not connect. T1-T6 and T11-T15 are 12vdc for their indicated sources and T8-T10 and T17-T20 are ground sources.
[attachment=52495:image.jpg]
Next is the schematic for logic grounds for the ecu. This is in the service manual, but very difficult to read, so my version simplifies it. This is why I wanted to use a OEM harness to rewire. One so I can keep OEM color codes. Two, so the main sensors are shielded correctly to repel noise from getting to the ecu and messing the input signals. Yes its important, its the reason my motor blew because electrical noise got to my ems because the shielding was wrong for the crank sensor, noise made the ems loose timing, and boom, melted pistons even though the datalog showed everything perfectly fine. it happened on a dyno, so trust me, I'm making crap up, lol... Anyways, you can do what the after market world does like rywire, chasebays, etc does and twist the wiring and this cancels out noise of the positive and negative flow of current, or, you can use this, use OEM wiring, and do it the way Honda made it because the know what they are doing. its the safest and its proven. I wanted to keep everything going to the grounds Honda had things going to and to certain ecu pins Honda had things going to and the shielding gounds connected and going to where Honda had them connected. I wanted it wired how Honda had it if you couldn't tell, lol. So here its, an easy to read ecu logic grounding schematic for your pleasure.
[attachment=52496:image.jpg]
So, on my harness, I did delete the secondary O2 sensor, cause I don't care about it as I run a ems. I also deleted the vtec oil pressure switch and spliced it from the vtec solenoid to the oil pressure switch. That way, if i did go back to oem ecu, i still have vtec as both of those are 12 volt signals to operate. So splice into the vtec switch wire and run it to the vtec oil pressure switch pin and you will be set. I'll still have a CEL for the secondary O2 sensor. I also deleted the air pump crap too, so I'd have one for that too (the C101-8 pin).
I hope this helps out the community. Probably not so much for people tearing apart a harness, but the pin outs of the connectors as I had a hard time finding anything. Good Luck if you under take a rewire!!
Hey guys. I blew my motor a few months ago and been cleaning things up since my motor is out. So I decided to rewire my engine harness to clean it up some. Also, more important if you plan to do this yourself, is the C101 pin out and terminal block pin out incorporated in the engine harness. Also a schematic of ecu logic grounds and wire shielding grounding.
To start, I bought expanding non split wire sleeveing from cable ties and more website.
http://www.cabletiesandmore.com/ExpandableSleeving.php
You need a hot knife to cut the stuff, if you don't, the ends will fray. Also need shrink wrap to melt at the ends to keep it from fraying and clean. Bought my shrink wrap from harbor freight along with the hot knife. I used the marine heat shrink because the glue sticks well to the wire wrap and holds tight. You use the 2 smaller sizes the most, I went through probably 2 and a half cases of the smaller sizes. that's with cutting them into 1/4's and halves for different spots. Also got my de-pinning tools from there. I use 2 different one. A thicker one for actual sensor connecter and a smaller one for ecu de-pinning. I use the straight ones from each of these kits
ecu de-pinning tool - http://www.harborfreight.com/5-piece...-set-1816.html
sensor de-pinning tool - http://www.harborfreight.com/4-piece...set-66836.html
hot knife - http://www.harborfreight.com/130-wat...ife-60313.html
marina shrink wrap - http://www.harborfreight.com/42-piec...ing-67598.html
You pretty much put the wrap around the wiring, slide the shrink wrap over and use a heat gun to shrink the tubing. Be careful, cause the sleeveing will melt also if you point it towards it for more than a second, you have to keep the gun moving around the shrink tubing to shrink it but not long enough to melt the sleeving. Practice first so u don't have to undo your first one like I had too, lol...
But you gotta route the wiring however you wanna do it. The possibilities are endless on routes you can go. You can hide everything the most you can or do what I did, just make the harness look better and still be user friendly for working on the engine. Its all up to you and what you want.
Here are my pics from before till after. Remember to keep some slack on the #1 coil wiring cause if you already have or plan to get a standalone ecu and possibly certain instances with the stock ecu, you will want to be able to get a timing light ring around the #1 coil wiring to check timing or sync timing with ems's.
[attachment=52486:image.jpg]
[attachment=52487:image.jpg]
[attachment=52488:image.jpg]
[attachment=52489:image.jpg]
[attachment=52490:image.jpg]
[attachment=52491:image.jpg]
[attachment=52492:image.jpg]
[attachment=52493:image.jpg]
Now I searched quite a bit to find a good engine harness to chassis connector pinout. That's the blue and white connector at the end of the engine harness often referred to as the C101 connector. Do not mess this connector up as there is no aftermarket version. You can only get it from another engine harness or possibly from the dealership. But the white pieces fold up then you take them off and de-pin it from the top and bottom by pushing in the middle of the connector. I'll have to get pictures as I didn't get any. anyways, for the pin out, I made one for our s2ki community. I also made one of the blue terminal block that's wrapped up with the engine harness and the logic grounding for the ecu/engine harness. I made these because you will not find them anywhere. possibly the C101, but not for the main sensor logic grounding and the terminal block. I have a service manual and its not in it. you can use the service manual for everything else like wire colors/sensors/ecu pinout/etc, but not for what I'm about show you.
So, The C101 Connector Pin Out. Pretty self explanatory. The places that say "Engine Harness Terminal #" is the blue terminal that's in the next pin out. Again, the C101 connector is at the end of the engine harness and connects to the chassis harness by the ecu connectors.
[attachment=52494:image.jpg]
Next is the blue terminal junction box that's integrated by the end of the engine harness, its wrapped up in black tape and most of you probably never even seen it before if you've never unloomed the harness before. All it is is a junction box of 12vdc power and ground. T1 (terminal 1) through T6 is power source for injectors 1-4 and the IACV and getting power from the C101 connector pin 1 (or C101-1). So, you can mix match any of these terminals a get the same results. I have three OEM harnesses and they are all different. The main sources are always the same (T1 for injectors, and T11 for coils), but any order will work for T1-T6; T8-T10; T11-T15; and T17-T20. If you take the top of the terminal off, you will see a bar of male connectors and splits where it does and does not connect. T1-T6 and T11-T15 are 12vdc for their indicated sources and T8-T10 and T17-T20 are ground sources.
[attachment=52495:image.jpg]
Next is the schematic for logic grounds for the ecu. This is in the service manual, but very difficult to read, so my version simplifies it. This is why I wanted to use a OEM harness to rewire. One so I can keep OEM color codes. Two, so the main sensors are shielded correctly to repel noise from getting to the ecu and messing the input signals. Yes its important, its the reason my motor blew because electrical noise got to my ems because the shielding was wrong for the crank sensor, noise made the ems loose timing, and boom, melted pistons even though the datalog showed everything perfectly fine. it happened on a dyno, so trust me, I'm making crap up, lol... Anyways, you can do what the after market world does like rywire, chasebays, etc does and twist the wiring and this cancels out noise of the positive and negative flow of current, or, you can use this, use OEM wiring, and do it the way Honda made it because the know what they are doing. its the safest and its proven. I wanted to keep everything going to the grounds Honda had things going to and to certain ecu pins Honda had things going to and the shielding gounds connected and going to where Honda had them connected. I wanted it wired how Honda had it if you couldn't tell, lol. So here its, an easy to read ecu logic grounding schematic for your pleasure.
[attachment=52496:image.jpg]
So, on my harness, I did delete the secondary O2 sensor, cause I don't care about it as I run a ems. I also deleted the vtec oil pressure switch and spliced it from the vtec solenoid to the oil pressure switch. That way, if i did go back to oem ecu, i still have vtec as both of those are 12 volt signals to operate. So splice into the vtec switch wire and run it to the vtec oil pressure switch pin and you will be set. I'll still have a CEL for the secondary O2 sensor. I also deleted the air pump crap too, so I'd have one for that too (the C101-8 pin).
I hope this helps out the community. Probably not so much for people tearing apart a harness, but the pin outs of the connectors as I had a hard time finding anything. Good Luck if you under take a rewire!!
The following users liked this post:
pezee (12-21-2018)
02-09-2020, 11:43 AM
#2
Wiring of s2000 ecu
First time post, looking for some help with project I am currently involved in. I have a 1965 and have fitted s2000 engine (ap1) got all the mechanical side sorted jst having some trouble with the wiring. I am attempting to use the standard ECU and have managed to lable all pins from ECU and have sourced interior loom to utilise plug A on the ECU. Also with the help from your amazing wiring diagram I have managed to sort out the wiring on the blue plug that comes from the engine harness (c101)
I have also removed Immobiliser chip from the ECU and obvioulsy ran my own supply to the fuel pump.
I have powered up all the feeds and gounded all nessasery earths. If I try and use the kick wire to turn over starter engine turns over but no spark or fuel. Tried testing for power at coil pack I have 12v and clean earth on 2 pins nothing on the other even when turning over.
Also managed to wire in Obd 2 port from ECU using the K line but both my obd readers jst come up with unable to connect to ecu.
Almost seems like ecu has no power not sure why tbh. is it faulty, immobilized or is there something else I could check.
Any help appreciated
I have also removed Immobiliser chip from the ECU and obvioulsy ran my own supply to the fuel pump.
I have powered up all the feeds and gounded all nessasery earths. If I try and use the kick wire to turn over starter engine turns over but no spark or fuel. Tried testing for power at coil pack I have 12v and clean earth on 2 pins nothing on the other even when turning over.
Also managed to wire in Obd 2 port from ECU using the K line but both my obd readers jst come up with unable to connect to ecu.
Almost seems like ecu has no power not sure why tbh. is it faulty, immobilized or is there something else I could check.
Any help appreciated
02-10-2020, 12:28 AM
#4
This is a possibility, could also be the fact that its a uk spec ecu and there is more to the immobilizer than a fuel pump cut off. The US and JDM ecus only have cut off for fuel pump so can be bypassed by linking out fuel pump relay. Might try and source JDM ecu and try again. Thanks for your reply.
The following users liked this post:
Slowcrash_101 (02-10-2020)
03-12-2023, 01:40 PM
#6
Old thread and post, but thank you for this. As I've owned my S2000 for several years now and as it's evolved throughout my ownership, several things on the OEM harness have become redundant. Plus, with it being a 20+ year old car at this point, a majority of the original tape on the loom has become brittle and is falling apart etc. I just bought a used harness off of eBay; I plan on removing the things no longer necessary for my car, like the primary & secondary o2 sensor wiring, all of the air pump stuff, the evap stuff, and the cruise control stuff....I've got about 8-10 connections that are no longer going to anything. Going to buy new connectors for all of the connections, get everything all measured out and mocked-up, figure out where and how I want everything branching off, and then I'm going to Raychem the whole harness.
The biggest thing though, is I'm going to run the harness under the intake manifold, so I'll be re-pinning the engine harness with longer wires for the injectors. I was going to just extend the ones on the harness in my car, but I figured it's much safer to just start with a clean harness and re-pin with the appropriate length wires instead of worrying about solder joints potentially failing....Plus it didn't sit well with me that some of my harness would have the factory corrugated loom on it and the other parts won't. A $100-150 engine harness off of eBay that you put some time into will be far cheaper than buying a "MiL sPeC" harness for $1600 that is essentially the exact same as what I'm looking to accomplish now.
The biggest thing though, is I'm going to run the harness under the intake manifold, so I'll be re-pinning the engine harness with longer wires for the injectors. I was going to just extend the ones on the harness in my car, but I figured it's much safer to just start with a clean harness and re-pin with the appropriate length wires instead of worrying about solder joints potentially failing....Plus it didn't sit well with me that some of my harness would have the factory corrugated loom on it and the other parts won't. A $100-150 engine harness off of eBay that you put some time into will be far cheaper than buying a "MiL sPeC" harness for $1600 that is essentially the exact same as what I'm looking to accomplish now.
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