Function-------------------Black Plug(H33-4)--------------------------On Car
+30 Power-----------------Pin 5, White/Pink---------------------------Find your self any constant power.
+15 Power----------------Pin 21, Yellow/Gray Pin 23, Green/Gray----Again, find it yourself. I just used the coil circuit.
DI/AIC/Injectors +15-----Pin 2, Green/Red--------------------------Its up to you.
Main ECU relay------------Pin 12, Blue/Gray--------------------------Main ECU relay. I did NOT use the stock relays. Nor this lead.
Fuel Pump relay------------Pin 11, White------------------------------Fuel pump relay. Again I did NOT use the stock relays. Nor this lead.
O2 Pre-Heater-------------Pin 8, Yellow/Gray-------------------------This needs +15 switched power. I used the coil circuit.
Brake Light Switch----------Pin 25, Violet-----------------------------Run it over to the brake light switch. Since I think the only person who needs to know when I'm on the breaks should be behind me....I didn't hook it up.
Speed Signal---------------Pin 7, Pink/Black(?)---------------------Above Jetronic Pin 1, Green (pic below)
Check Engine---------------Pin 22, Yellow/Green-------------------Above Jetronic Pin 4, Green/gray(?) (pic below)
Engine Speed(RPM)--------Pin 9 Green/Red------------------------Above Jetronic Pin 3, Blue (pic below)
Shift up--------Pin 22(H-33-5) Blue/Yellow------------------------Above Jetronic Pin 2 Yellow, Blue (pic below)
Grounds-------------------On end of T5 harness---------------------------Nice rust free spot.

^That came off Saablink, I found it to be a pretty helpful list when combined with a wiring diagram for the ng900 harness I used. The diagram was not for the correct year though, so like Drew said, some of the colors were different. But it didn't take too much to figure things out.

Because my car didn't retain the stock heater, I was able to put the ecu inside the cabin where the heater box would normally pass through the fire wall without extending the harness. As for the rest of the harness, I only needed to extend the wiring for the MAP sensor, intake air temp sensor and a few inches to the wiring for the AIC valve so that it could be routed nicely. I think it is definitely easier to use the existing T5 engine harness and just build something to adapt it to the car.

In MikeD's post he talks a lot about the big gray plug. If I was using a 9000 harness I think I would cut that out and add in something more compact like a deutsch connector, weatherpack etc. That big gray plug is just kind of bulky. The NG900 uses a smaller plug (the H33-4 referenced above) that I retained. Not sure what the plug type is called, but the are used all over in the ng900/9000, like whats used on the DI. Everything going to the car side of things runs through there, so it should make for a nice place to build an adapter harness off of, and thats what I did. The actual engine harness just needs to be unwrapped and then re wrapped to taste so that everything routes nicely around the engine. This is what I ended up with:

And this is what the car side I made looked like:

It includes the wiring that goes to the fuel pump, relays, plug that goes to the engine harness, and the wiring that goes to the gauge cluster.

Since I didn't retain any stock wiring in the car, I can't be of much help in terms of where to find things on the car side etc. I did use the stock main/fuel pump relays though. This is an area where some people have struggled and end up using other circuits. From what I found, I believe that the ECU will only ground the fuel pump relay if the main relay is triggered. So if you don't use the main relay ground from the T5 ecu, the fuel pump relay won't work.

I am going to do the same thing with mine, bring the harness in the center hold in the dash where the heater box sits and mount the ECU on the inside dash, along with the relays and all the fuses. A 9000 harness should work perfectly for that, since that's where the ECU is normally located anyway. Plus you get the big bulkhead connector to disconnect the whole harness and leave it attached to the engine for engine swaps.

The only thing I am unsure of and haven't done any research about is where to pull a vehicle speed signal from? T5 needs to know vehicle speed to do some of the boost control stuff. It normally comes from a wheel speed sensor, so you could tap that if you have ABS hubs and wheel speed sensors. I've also read the later C900 speedometer output that goes to the cruise control will do this function.

But I don't have any of that stuff on the 99. If it could be programmed out that would be the best, but if absolutely needed I'd have to install one of my ABS front hubs and an outer CV joint with a trigger wheel to get a wheel speed signal.

Geoff wrote:I'd like to install T5 on my dad's '90 which has never ran right because of the whacky EGR stuff. But, I wouldn't be able to get him to commit to it and I don't want to spend the time. Maybe I should convince him to give me the car instead.

Granted my '90 SPG had other gremlins as well but it too had EGR and it was the devil. That took the formative years of my c900 n00bery to finally get running correctly. My friends '90 didn't have that awful system and it ran like a champ. I wish it had been as accessible to get trionic running back that, I may have kept that car longer.

As for the speed sensor I think it's the 89+ speedos that send the right signal, not really sure what the difference is between models though but I guess that doesn't help a 99. I thought I remembered a guy with a speed sensor coming out of a 9000 trans that bolted into a 900, I'll look around for it.

*found it:
1. 9000 speedo sensor adapted (in fact, direct bolt on ) 9000 gear drive on left, 900 on right





I think he also used a 9000 speedo so maybe that's not what you're after either.

That is 99Sven's write up on SC. I'll ping him to see if he has the photos locally (harddrive) and he can upload them in this thread.

I found them in my folders. Not very good photo documentation, but some work in progress shots.

Drew my plan for the speed signal (for a non 900 application) was just loop back the tach output (58) to pin 39. The manuals show it as the same type sin wave. If you dont have a speed signal you will get base boost all the time as it effectively thinks that you are not moving. So doing this makes the trionic think that you are going really fast all the time. That way you can get full boost without the need for a speed signal. You won't have limited boost in gear 1 and 2, but who wants that anyway

Depends on what your using for a speedo in the car. We used a aftermarket VDO guage in Luke's current rally car driven by the 9000 electronic speedo sensor...or do what Luke said if you're using the mechanical pickup.. or do both and still get rid of the 1st/2nd gear thing boost limit :)...but that could probably be programmed out anyway.

Nice, good idea Luke. That way I can keep the 99 speedo and tach, boost limit would be nice, but definitely not essential.

Just saw this thread and browsed it quickly. Regarding the relays, there have been lots of problems reported on the web with people trying to use the stock C900 relay setup. DON'T DO THIS. I simply made a relay set up with the correct wire diameter and set up that duplicated exactly the '94 9000 trionic relay configuration. I have had zero problems over the course of 70k miles.

I cut out the stock harness. I only used the big grey and red fuel pump fuse wire that runs along the firewall. KPAero did a nice install with his T5. In defense of Mike, he did grab a six pack and did the install in a few hours. He really did some outstanding work on tuning and figuring out all the small details of this install.

I am tired from a day of backcountry skiing so I will keep this short. I would be happy to answer any questions related to my install.

Gregg, what's the reasoning behind not using the c900 relays, wire diameter not included? Is it just setup related or is there something special about the relay itself?

Ok, the cold snowy weekend provided an ideal time to sit inside by the woodstove with a cup of tea pouring over the manuals (both NG 900 and C900) and the notes I had made from about 8 years ago. I used a few hints from what Pascal had posted above but I tried to mostly start from scratch in-case anything had been documented incorrectly, etc.

I also managed to grab a '95 NG900 harness to verify things from.

Anyway, I put together some PDF's of how I would approach the project, I may actually do this to my '88 this summer as I believe I could do it such a way that it was 100% plug and play, no cutting of wires involved and could be reversed if desired. The LH harness could be lifted out or pulled to the side and T5 more or less inserted in place.

Take these with a grain of salt at this point, but I think its all right

That's awesome. Now to just grab a shit-ton of those LH connectors to adapt to the T5 harness to. I think I may have a few already. You read my mind, I just didn't look at the LH connector setup yet to see if it easy access to those components...the things you do on a Sunday afternoon...

We should do a harness building weekend...this sounds like a fun thing for the 2.45l 16v motah.

Just to add clarity, this is the "H33-4" connector that is referenced in the diagrams above
It clips right out of the harness on the NG900 and pretty much all the external leads come through that connector. We can easily grab another foot of the NG harness on the backside to splice into.

H33-4 is left, main ECU connector to the right.




A pigtail from the car side of the NG900 to splice into

When is the next trip to the yards?

I may tag along on the next U pull it trip. I could use some guidance to pull the necessary bits for my T5 setup.