gerrb

iTrader: (34)

Let us re-introduce the 40 pin ECU Connector and the most common Body Plugs you will extract from your SC300 harness. Again , which body plugs depend on the harness you have which will depend on your car.

40 PIN ECU CONNECTOR





Nothing special , you take out pins the same way you do on the 80 pin ECU Connector and I hope you by now know the pin numbering.

gerrb

iTrader: (34)

Let me introduce here the different body plugs used on an SC300 / SC400 .. depending on the year / model / car specs , there maybe more which I have previouslly shown.

The Most Common Body Plugs



I have seen some SC300 with more body plugs like this one. It has3 or 4 more body plugs on top of the common ones.

gerrb

iTrader: (34)

How do you determine which is pin #1 ? Same method, hold the connector with the lock on top and you have pin #1 starting top left. TAKE NOTE : When I say the number of pins, I mean the number of slots for pins. It doesn't necessarily mean that all the pin slots are filled with pins and wires.


IK1 Connector ( 23 pins - Orange )





to remove pins -> each side has a lock with two latches on top , pry those two latches



then the lock slides down and exposes the pins which you can push while you pull the wire from top





IK2 Connector ( 25 pins - White )





unlocking and removing pins is just like IK1

gerrb

iTrader: (34)

IJ1 Connector ( 14 pins - Gray )





unlocking is just like the big Aristo gray plug whose lock is on the side .. pull a bit and pry the pin on top while pulling wire





IJ2 Connector ( 17 pins - Gray )





unlocking and removing pins is just like IK1

gerrb

iTrader: (34)

II1 Connector ( 12 pins - White )





unlocking and removing is just like the big gray Aristo plug



SHORT Connector ( 6 pins - White )





unlocking and removing is just like the big gray Aristo plug

gerrb

iTrader: (34)

Now that we have covered most if not all of the plugs and wires on your Aristo 2jzgte harness , we need to take the 40 pin Connector and Body Plugs from your SC300/SC400/MKIV engine harness.

This picture shows you how some wires go from the 40 pin connector to the other body plugs. All those Body plugs are already pinned with wires. We are not de-pinning any of them FOR NOW. Since these are coming from the car for which you are doing the harness , pinning on these plugs are presumably good and done for us. We will just have to verify them. The most we need to do if ever is remove those not needed or move pins if there is a need.




So now the question is from where to where do we cut our body plugs and the 40 pin ECU connector from the SC300 / SC400 / MKIV for which we are doing the harness ?

Do not arbitrarily go and just cut it 30 inches away from the plugs and roll the rest in a ball of wire just like pictured here ... PLEASE NO !!!

gerrb

iTrader: (34)

You have to observe and evaluate your harness. Which of the plugs on your harness are unique to your car and do not connect to any of the components in the engine you are taking out ? You are more likely to need them .



If you have done this at least once , you probably by now know which plugs you will need to merge with the Aristo 2jzgte harness.

So what are the plugs I need to get from my current engine harness and how can I be sure I don't miss any plug that needs merging with the Aristo 2jzgte harness ?

For the SC300/SC400/MKIV , I can tell you right now which are all the plugs in your current engine harness you need to keep and merge with the Aristo 2jzgte harness and which one to just throw and discard just because I have done it before. But again the SC300 harness you have might not be the same SC300 harness that I have which is a possibility as I have previously shown with pictures.

Let's say nobody is there to tell you which one. The process of elimination will be of big help in determining what plugs on my current harness I need to take and merge with my Aristo 2jzgte harness. You should have the most updated CHART now for reference .

On your SC300 harness, you will take out all the plugs and wires that go to the 80 pin ECU connector that you have worked on so far on the Aristo 2jzgte harness. You surely don't need them if they are already on the new harness you are working on.

You see this is another good reason why I wanted to work on the plugs / wires that lead to the 80 pin ECU connector first in as much as I can. It will help those who are new in the elimination process ..that is determining what plugs is left from my current SC300 harness that I need to merge to the Aristo 2jzgte harness. For those who have done it before or can read diagrams or knows every component on the engines they are working on , this isn't even necessary. I am trying to help those without any harness build experience and are not also auto mechanics that know their engines by heart.

I usually start taking out all the wraps and covers to clean it up to give me a better view but not allowing it to be messy or tangled .




Continue removing all the wraps all the way down to every plug . Re-use those hard plastic covers in your new harness if you can. There is a lot of heat near the firewall behind the engine. The plastic cover helps a lot in protecting the harness . Exactly why Lexus used it.

gerrb

iTrader: (34)

This SC300 harness is basically all unwrapped. I left some bits and pieces just to keep it still organized and not becoming a ball of messy wires.



We want to find all the plugs that are in our old harness and needed to be merged or incorporated in our 2jzgte harness.

For those who know well the Aristo 2jzgte and the SC300 2jzge engines , those who have done a 2jzgte harness for a swap... it is easy , just by looking at the plugs of this harness , right away can pinpoint which plugs they need to get from this harness.

Like , they would say , oh these are the injector plugs . Let me take out all of them and their wires now. I don't need them.



or will say , oh that is for the SC300 igniter , noise filter and coil. I don't need that and I will take out those plugs and wires



And they will continue doing it with all those plugs and wires they know they don't need until what is left is what is needed to be merged with the Aristo 2jzgte harness.

And some don't even have to go through that elimination process even if they know what is not needed. All they do is take those wirings and plugs they need to merge with the Aristo 2jzgte harness. Once you have done it once or twice , you can be on the same boat. You can skip all that lengthy process of elimination.

gerrb

iTrader: (34)

But what about those who never did a 2jzgte harness for a swap before and really have no idea which plugs to get from the original harness ? I suggest you use the process of elimination

Get your updated Chart . By now you know that you have worked on every plug that is on your Aristo 2jzgte harness.

You will use the 80 pin Connector on your Chart . We know that from the SC300 harness we need the 40 pin connector and all those body plugs / connectors you see in the picture except the 80 pin connector . Though if a pin from the 80 pin connector has a wire that connects to the other plugs , we have to make sure that is done on our 2jzgte harness too. So , we start removing unnecessary wires from SC300 80 pin connector.





Start with the first line of your Chart , Pin 1... check your SC300 80 pin connector . .. does it have a pin and wire on that slot ? In this case , no , so you have nothing to do. .. proceed to the next line in your chart.

It shows pin 3.......check your SC300 80 pin connector ... does it have a pin and wire on that slot ? In this cas , yes , so take out the pin , pull the wire up to 6 inches before the plug then cut it. You want to keep the plug with a pigtail so you can reuse it in the future... proceed to the next line in your chart.

It shows pin 5 ..... check your SC300 80 pin connector ... does it have a pin and wire on that slot ? In this case, yes ,so take out the pin , pull the wire up to 6 inches before the plug then cut it. .. proceed to the next line in your chart.

It shows pin 6 ......check your SC300 80 pin connector ... does it have a pin and wire on that slot ? In this case, yes ,so take out the pin , pull the wire up to 6 inches before the plug then cut it. ... proceed to the next line in your chart.

What you are trying to do is remove all those wires on your SC300 harness that you don't need on your 2jzgte harness because you already have them. Once you are done with all those pins on the 80 pin connector , what should be left behind on the SC300 harness would be wires / plugs that we don't need on the Aristo 2jzgte harness and a bit more that where not removed by the process we just did. I will show you how to remove them next.

TAKE NOTE :

a) IF you are taking out a pin from the SC300 80 pin connector and it's wire has connectivity to any of the body plugs or to the 40 pin connector . don't take it out for now. We will do them last. You want to make sure that connectivity is transfered to your Aristo 2jzgte 80 pin connector.

B) When you pull out a pin / wire from the SC300 80 pin connector , if there are wires T'ed or branching out from it , take those wires out too and cut them also 6 inches near their plug.

I normally don't do what I asked you to do above since I know what plugs/wires I have to get from the SC300 .... but for the sake of this tutorial , I decided to do it so to show you what we end up with if you do it . This is what I came up with . I have less wires now on the SC300 80 pin harness.



So what are those left over wires from the SC300 80 pin connector ?

a) around 6 of those wires have direct connectivity to the body plugs or 40 pin ECU connector that is why I didn't remove them yet.
b) some of them are basically just for the SC300 like wires for MAF which the Aristo 2jzgte didn't have. .. .....we will find out next

You see when I told you to take out a pin , take out the wire and cut it 6 inches before the plug , some of those plugs didn't have their other wire end or go back to the SC300 80 pin connector so the connectors are still there.... just like pictured ...



Now time to do the reverse to further to investigate those wires still there on the SC300 80 pin connector

a) from the plugs trace their wires , if they end up at the SC300 80 pin connector , take out their pin and wire ....

or simply get the 2jzge 80 pin configration chart and see what are those pins and if you don't need , take them out with their wirings






It may sound to be a ridiculuous process but will help you determine what you need from your current SC300 harness if you don't have the slightest idea of which plug / wire you need from your SC300 harness.

Like on my end , I don't have to do that pin by pin removal ...II can just cut those wires since I know where to connect them or if I do the process of elimination , I can do a bunch at once and would start from the plugs , pulling the wires towards the 80 pin connector since I know which plugs are not needed and will end at the 80 pin connector. The tedious process above is for those who do not have the slightest idea of what plug / wires you need to keep and merge with the Aristo 2jzgte harness.

gerrb

iTrader: (34)

On the process of elimination , taking out wires from plugs you don't need , if there is a wire that is T'ed ..one wire going to a body plug and the other to the 80 pin connected .. just cut the T'ed wire so you can take out that wire and its plug ... remember I asked you to leave those wires for now that has connections from the 80 pin connector to one of the body plug

sample of those wires






Now after going through the 2jzge engine pin configuration reference chart and going through the left over plugs I mentioned in the previous post , pulling all the unnecessary wires. I am left with this

Basically all the plugs that I don't need are gone .. what is left (except for 3 or 4 which I know I don't need but whose wire goes to the body plugs like gauge temp sender , AC plug so I kept them for the moment ) is what I need to be merged with my Aristo 2jzgte harness .



Observe what is left on the SC300 80 pin harness.. almost nothing , what is left are those wires that have Ts to the body plugs. I want to see later if they are even needed during the merging process if not , just take them out. There was only really one wire left that went all the way to one of the big plugs in front of the fuse box which is EB2 .



This is what I got out from doing the process




These are basically what I need to merge with my Aristo 2jzgte harness... left over from the elimination process





Same plugs I posted on the previous question and answer post... right ? So the process of elimination was effective after all but really tedious to be honest. Never did it before , even on my first time since I knew how to read diagrams and was kinda familiar with all the plugs of the 2jzgte , 2jzge and 1uzfe engines.

But once you have experience working with all different SC300 /. SC400 harnesses , am pretty sure you know the plugs you need to extract and merge . Again this was just to help those who doesn't have the slightest idea of which plug to get from the SC300 harness.

gerrb

iTrader: (34)

So to answer the question ? Up to which part of the SC300 harness , where we are taking out the 40 pin , body plugs and other connectors be cut ?

Before I answer that .. let me go one more step here for those who went through the elimination process..

I told you a minute ago that 3 or 4 plugs that I don't need I haven't taken out just because their wires go either to the body plug or the 40 pin connector ...

Those on the left of the picture



close-up picture



Pull them out and roll them going nearer the body plugs ..like pictured below.. that is still a lot of wires you have isolated. Why haven't I cut them or remove them in the previous process ? Cause it will be easier for me to determine later where those wires should go to my 2jzgte harness cause they still have the plug. Like gauge sensor wire, I look for the wire at the 2jzgte harness which is for gauge sensor wire and cut one , connect the other.. saves me time tracing wires. I suggest cut those wires at a portion of the harness that do not go inside the firewall ...why ? just trying to minimize extended / soldered points going through the firewall. why ? when you insert those connector inside that firewall hole .. you pull and push...possibility of disconnection of soldered points.... less soldered points going in that area , less possibility of problems arising from pulling and pushing that harness....if you get soldered points disconnected and is behind that A/C blower box .. you have no choice but pull out that harness out of the firewall hole again .




Now I can answer that question , where do I cut the left over wires now ..my answer is NONE..You are not cutting anything cause the left over wires are wires that go to the actual plugs we are merging with your 2jzgte harness...



those wires go to these plugs so you are not cutting anything.. they have to be merged to your 2jzgte harness

gerrb

iTrader: (34)

These are the most common plugs you need to merge with your Aristo 2jzgte harness

Alll those plugs near the 80 pin connector ..


The two big plugs infront of the fuse box and its wirings


The Lexus SC power steering plug


for the SC300 , depending on what alternator you use , the round plug ..and have to incorporate its wiring on the harness. The SC400 alternator wires are not on the harness just like the SC300 .


heater valve plug


horn plug

gerrb

iTrader: (34)

Part III : Merging the Aristo 2jzgte harness with the 40 pin ECU and Body Plugs

This part should be easy since you already know where some of the wires are going , meaning to which Body Plug. You just have to cut and solder to the right length so much so that the body plugs and the 40 pin ECU Connectors are near the 80 pin ECU Connector . The other Body Plugs pins / wires we haven't covered so far , I will cover on Part IV. The only hard part here is you are dealing with more wires now so working systematically is a must so you don't get confused.

At this point , this is how Aaron's harness looks like for his SC300 2jzgte swap with Manual Transmission. Observe that area where there are no auto transmission plugs but have 7 extra wire there I can use when the need arises.The backup light switch wiring will actually go in that area. All in all , he has around 15 extra wires in different areas of the harness plus the +B and ground wires for future use. I will have to modify this later for some plugs due to the fact that he wants to use an aftermarket MAP and Air Intake Temp Sensor.The wires for the stock / oem ones located on the plenum of the intake manifold will be short for their new location and plugs are different. Thus , it will always be nice to have or at least know every aftermarket part you will use before working on the harness.

gerrb

iTrader: (34)

I usually tie the harness in different areas just to keep it clean. When you do the merging, remember you are dealing with more wires. So those area I won't need during the merging , I tidy up.

This area I don't need except that I will lay over some connectors and wires (e.g. alternator , horn , power steering , front fuse plugs)


This area I don't need to do a lot . These are the extra wires and the 80 pin connector whose wires have all been extended already.


This is the area where most of the MERGING will take place. Most if not all of those wires are going to be connected either to the 40 pin connector or body plugs. Being labeled , it would be easy to know where they go by just looking at your CHART

gerrb

iTrader: (34)

Before the merging, this is how the second harness for a 1992 SC300 2jzgte with auto transmission looks like.