Wiring

[SeanDean]

Well I took some pictures of my wiring, but they are really crappy and it's hard to tell much, I will try to get some better pics tomorrow in the daylight and actually remove the harness. My harness is a 1995, but some of you prolly remember I have a 97 VH41.

It's hard to say exactly what I did with the wiring because I did it 2 years ago. But I remember the basics.

Anyway heres the crappy pics.....











Probably useless I know.

A few things I do remember is that I used the stock 240SX ECCS relay and fuel pump relay, wired them to the appropriate wires on the Q45 engine harness, and then I installed my own relay for coil power and injectors. I'm not sure why, usually on Nissan swaps I have done, the injector and coil power relays are in the engine harness already, but maybe on the Q they were external...

Anyway, we should just make this a wiring thread and keep contributing.

I will have a look at the FSM's again and figure out what exactly I did, but basically, here's the basics for any swap:

ECU power,Coils and injectors power, ECU trigger output for the fuel pump relay.

Then it will start and run.
Modified by SeanDean at 3:56 AM 10/1/2007

[zehnder]

I know there is relayed power to the coils, but you made mention of relayed power to the injectors too. Where is this relay located?I just saw a red wire in the blue plug that runs through the engine harness that branches into two reds that plugs into the sub harness at right bank of engine. Am I missing something? I`m in the process of wiring up a VH into a Dodge Dakota and am sorting through what is essential and what I can use from the Dodge. Powering up the ECU is what? Pin 43 start signal from ignition "start". Pin 45 is "start,run"from ignition.Pin 48 power source for sensors from ignition "start, run". Pins 49,59,109 power from ignition "start,run".Pin 58, fused power from battery"always on". Is that it for power into the ECU? Pins 6,18,19 go to fuel pump relay & pump. How, or from what source, are you running 12V power to fuel pump relay then to the pump?Is it "start,run" or "always on"? Also, FSM shows Ignition relays 1&2,Why is there two relays? Can I just use the Truck`s ignition relay? Every time I think I got my brain wrapped around the subject I end up having other obligations interfere!
Modified by zehnder at 10:17 PM 10/2/2007

[tmorgan4]

I like this discussion a lot. Should help everyone (including myself) once we get everything finalized!

Is there anyone can do a pin-out with details on the connectors near the ECU plug? Details on pin F51, F52, F57, and F58 will help sooo much.

Zehnder...Thanks for the info. You listed a couple wires in there that I wasn't able to trace. Im looking at the ECCS wiring harness and a few of those wires go into "Joint Connectors" and I lose them there. They must continue on another diagram.

I will start making a little diagram right now with all the known wires and see if we can get some people to fill in the blanks. Be back in a few.

[zehnder]

TMorgan,I`m seeing pin 51 as a cam shaft reference signal.Pins 52,57 are showing as not being used at all.Pin 58 is direct power from battery through a fuse at 12V. In above photos, there is a blue plug with a red wire.This, seems to me,splits into two red wires that go through the engine harness that end up at a plugin at the sub harness above the right power transistor on right valve cover. These wires supply 12V to injectors which in conjunction with 8 injector wires from ECCS, operate injectors.At least this is what I think. My question is whether this 12V power is relayed power or "always on" power.
Modified by zehnder at 10:41 PM 10/2/2007

[tmorgan4]

Zehnder...thanks for the help...I'm really going to need your help when I get my little drawing complete. I meant to type connector on the F51 F52 etc. above. In the wiring diagram for the ECCS system there are 4 plugs + the ECU plug and I'm wanting to get these 4 plugs drawn out and labled. Working on it as we speak.

[zehnder]

Yes, I see now you were talking about harness plug ins and not ecu pins.

[tmorgan4]

This is what I came up with so far. I'd like to add more info for specific pins (mainly power supplies, whether it's on in "OFF", "ON", "RUN", "START", specific voltages, etc.)

We need everyone's contributions on this board to figure out this wiring battle once and for all.

EDIT: CHECK NEXT POST.
Modified by tmorgan4 at 6:07 PM 10/3/2007

[RichZilla]

I have them all on paper. I worked it out a couple of weeks ago and found a few other things last weekend.

They're sitting in the Merc at work. I'll bring them home tomorrow and post them up. As far as I remember, I've worked out every pin in detail - even what I don't need for my car.

[tmorgan4]

RichZilla,

Thanks for the help. Quite a few of the difficult to find functions came from the list you made. Helped a bunch.

Here's as far as I got for the night on the diagrams. I DO NOT have the F58 (Brown) plug on my wiring harness that it shows in the manual. All of the functions that are shown on it are placed in the other connectors.

[tmorgan4]

So now for some questions.....

Why does the speed signal run from the dash into the ECU?

Why are there 4 Consult data link pins? On my VG33E harness there were 2 consult data link ports...one labled GST, one labled CST. What are these?

The fuel pump has an adjustable voltage which I would guess depends on throttle position. The 300zx's had this feature and many guys rewired it to have full pressure all the time by wiring in a 12V relay. In the FSM it specifies that this signal for the adjustable voltage varies between 0-2V.

Any other info to fill in the blanks is wanted as well!

[SSDwellah]

If it's like the other Nissans I've seen, then the speedo signal goes from the dash to the ECU because it's more critical to get it to the dash. The ECU usually only uses it for speed governing (although I guess they could theoretically use it for some kind of highway cruising EGR emissions crap but I don't think they do). Unless you have an A/T, and then I am not sure how the speedo signal is routed. In fact with some year 240SXs, many people would just cut the wire going to the ECU and still have a speedo with no governor. But be warned, I think they started putting 4th and 5th gear sensors in some cars so that they could speed govern by RPM-gear combination.

EDIT: I forgot to mention before. From the ECU, I'm guessing the speedo signal then goes back out to the ASCD for cruise control. That may be one of the "generic" ASCD pins you listed in your diagrams.
Modified by SSDwellah at 10:13 PM 10/3/2007

[tmorgan4]

The speedo won't be a big deal on my part since the one in my Pathfinder is purely mechanical. It worked when we towed it with the engine off. Just trying to help people out in the future if they are trying to get this to work. The governing part does make sense though.

[tmorgan4]

I'm having a hell of a time finding out what all of the wires that run up into the harness connectors instead of the ECU go to. I can identify the connector they go to but the drawing in the FSM labeling the connectors is so poorly done that I can't identify which connector is which.

Here's what I need from everyone. Any info on the following wires is needed!

Big White connector (F51):

Blue w/ black stripeRed w/ yellow stripeRed

Blue connector (F52):

Brown w/ yellow stripeRed (normal diameter)Red (thicker than normal)YellowGreen w/ red stripe

Small White connector (F55): (accidently labeled F57 which is wrong in picture)

Gray

I have some guesses about some of these but I'd like to keep this accurate.

[zehnder]

I`m almost positive that the thick red wire in the blue plug is to supply 12V power to the injectors.I noticed that this wire splits into 2 reds in C5 harness which plugs into S51(engine control sub harness)The plug has 5 wires- 2 red,gray,gray with blue stripe and blue with black stripe.The reds, I think supply 12V power to the injectors.Is this relayed power or fused battery power? Coil relay has brown with yellow wire to send power through blue plug.This wire splits in two and one goes to right bank and other goes to left bank coils. By the way,I have the 94 fsm but am working with 92 VH45DE. Are the wires and colors similar?I hope so!

Modified by zehnder at 9:19 PM 10/3/2007
Modified by zehnder at 9:45 PM 10/3/2007

[tmorgan4]

Thanks Zehnder. I think you're right about the bigger wires being power to the coils and injectors.

I'm using a '92 engine with the '94 FSM as well. The majority of the wires are the same but quite a few have major changes. The blue connector is nearly identical, but the big white connector (F51) is significantly different. Compare my diagram colors and locations I posted compared to the '94 FSM and that plug is completely different.

[RichZilla]

Big White connector (F51):

Blue w/ black stripe - coolant temp for dashRed w/ yellow stripe - A/T ECU pin 34Red - TPS fully open signal to A/T ECU

Blue connector (F52):

Brown w/ yellow stripe - Positive from coil relayRed (normal diameter) - Ignition positiveRed (thicker than normal) - battery positive (injector supply) - I only say battery positive because Nissan usually uses battery positive to power injectors). Yellow - I had yellow/white. It goes to the three pin plug at the front of the engine. I believe it may for the ambient temp sensor. Green w/ red stripe - Power steer pressure switch

Small White connector (F55): (accidently labeled F57 which is wrong in picture)

Gray - there is no pin in my plug where your grey wire is. Can't be too important. Unless you're seeing a grey wire that seems to go into the tab for the plug. These are everywhere on my engine but seem to be of no use at all.

Of note are: Oil pressure switch wire is not in the main loom. My engine didn't even come with an oil pressure switch plug. There are wires in the ECCS ECU that go to the auto ECU and do not go through the above listed plugs. You need to run these direct to the auto ECU.

My engine powered up with very few wires because the ignition and ECCS relays were still attached to the loom. If anyone needs help, let me know. I have only recently finished wiring up my VH45.

As for the fuel pump. Don't bother with the fuel pump control module. Just wire up the fuel pump relay using the pink/black wire from the small white plug. It's a negative trigger relay - so the ECU earths the relay.

Here's a quick table of these plugs that I made up. Sorry about the format. I am useless at such things. I much prefer a pen and paper. You might want to just add these to the unknown pins on your format Morgan.

http://www.freewebs.com/chemic...s.wps
Modified by RichZilla at 3:05 AM 10/5/2007

[zehnder]

Rich,If I don`t need the consult wiring and leave these wires unconnected, will they cause engine not to run right? Same with (blue plug in)power steering pressure switch , traction control , neutral signal to ECU (what is that?)I know that pressure switch for steering might effect engine speed while turning the wheel but will not having this stuff hooked up cause engine not to run. I am hoping you could have showed and explained how your wiring was layed out since you obviously have it running well. So far, I have engine cranking, When I turn key to "on", ECCS relay clicks and powers up ECU. Coil relay clicks and I`m assuming power is reaching coils because engine ran before with same harness.(I will double check though)Fuel pump relay clicks and I can hear the pump start up in low voltage mode. Pump runs for about 5 to 10 seconds and stops.I put a test light at one of the injectors and am getting 12V. I pulled off pressure line to see if gas was pumping and it is. But its not starting!

[SSDwellah]

I think leaving the CONSULT wires unconnected is fine. It should not make the engine run weird. IIRC from the last time I looked at the CONSULT protocol, there are just three wires: TX, RX, and CLK. They are unterminited on the other side until you plug the consult unit in the jack anyway. The consult hand unit set the communication rate via the CLK line (although there are certain valid rates, it's not completely arbitrary) and then the TX and RX are obvious. It's pretty much like basic RS232 from that perspective. Anyway, it should be fine to leave those out.

From what tmorgan4 was saying though, your cruise control uses the same interface so it would be out of commission unless you hooked it up. Most people doing this swap couldn't care less about cruise control though(ASCD).

[tmorgan4]

Richzilla.....I don't even know what to say.

You just saved me about 1000 headaches and a whole lot of time. You still looking for oversize pistons? I just got mine here in the States for $430 with bearings and rings. I really feel like I owe you and I remember seeing they wanted something like $300 shipping. My sister is going to New Zealand next semester for school...maybe I can just pack them up in her suitcase??!!!

Thanks so much!!! I will finish these diagrams and they will hopefully help everyone in the future with wiring up a VH45.

[RichZilla]

Morgan, you've got the wrong dude. I'm in Australia.

I spent many an hour working all of this out and feel that everyone should get this knowledge. Who wants to spend hours working it out for themselves?

Zehnder, I haven't connected the consult wires. Nor have I connected the engine light - mainly because the merc doesn't have one. If I ever have dramas with the way the engine is running, I'll make my own engine light and connect it to the ECU. I also didn't connect up the power steer pressure switch wire. This is only required when parking - when the engine is at idle and you're turning the steering. All it does it bring the idle up.

Traction control can be left off. I believe the neautral signal is for idle. On an auto, when you put the car in neutral or park, the idle goes up. I could be wrong there though. I've connected it anyway. It was easy enough.

With regard to your engine not starting, use a screwdriver - or a stethoscope if you have one and put it on the top of the injector while you're cranking. You should be able to hear it click. Check your spark plugs. If they're wet, you're getting no spark. Pull a coil out and put a spark plug in it. Earth it to the engine somewhere and look for spark.

The best way to diagnose an engine not starting is to work out what you don't have. All an engine needs to fire up is fuel, air and spark. Work out what you don't have and work backwards from there.

[zehnder]

Thanks RichZilla,will do as you suggest.

[T45]

There's really no need for a CEL. Just periodically check the codes from the ECU via the LED on it.

[zehnder]

one quick Question:The green with black stripe wire which , I believe , is hooked up to pin 43 of ECU and travels Blue plug in, is described as a "start signal". Is this wire important? And if it is , does it trigger a relay or just receive an Ignition "Start" positive voltage? I don`t have any Q ignition relays , and was hoping to use Dodge Dakota`s ignition switch system. I understand that relays to coil and fuel pump use Pink and Black wire for Fuel and Red and Gray for Coil and ECCS relays. Is the green and black used in a similar fashion or can I tie this wire in with a positive start signal from the Dakota?

[RichZilla]

Very important. It tells the ECU that you are starting the car and dumps extra fuel in and possibly turns your main relays on. Just splice it into any wire that gets voltage on cranking only.

[zehnder]

Rich,Thanks much, I figured it was important and spliced it in to start positive of the dakota`s ignition. I was just worried in case it was a ground trigger for ignition relay. Didn`t want to fry ECU. I still have to check spark at coils and plugs, but have been working 7 days a week at my "real" job. Thanks for the reply.

[tmorgan4]

I'm in the process of stripping down my wiring harness and trying to remove everything that isn't necessary.

I've run into a few questions along the way on plugs I couldn't decide whether I'm safe to remove or not.

1) Ambient Air Temp Switch...it appears that this switch is in place because of the A/C system. Page EC-129 of the FSM mentions the voltage depends whether A/C is on or off, as well as ambient air temp. I'm removing A/C....can I remove this?

2) Crankshaft position sensor....I was surprised to see that this sensor is not used to control the engine, only for diagnostics. What is the point of this sensor? Can I remove it safely?

[T45]

IIRC the CPS is a failsafe or backup the ECU uses in case the CAS fails.

[tmorgan4]

Wow...I made a big mistake and I was looking at the Pathfinder FSM instead. I wish they said the model on them somewhere once they were opened. I guess the way these engines are controlled stays fairly constant as I think what I said above stays true with the VH45 even though I was looking at the wrong manual. I've got the harness stripped about as far as I can and now it's time to solder on the connectors from the Pathfinder so it will be installed in the car with connectors.

[SSDwellah]

I can believe that, in fact I was thinking the same thing but I wasn't sure so I didn't respond. I think at that point it would have to fall back on some sort of simultaneous injection (at least 2 at a time) and wasted spark though(again at least 2 at a time).

[zehnder]

Hey all,Just came across a little extra time to tackle my wiring woes.Ecu is powered up.Getting codes 46 (secondary throttle pos. sensor not hooked up yet) 54 (AT wire,not hooked up).Engine cranks and am getting fuel,( #6 injector is probably bad, not getting proper resistance). I have coil relay power up through the power transistor and to coil itself (I took out #2 coil and plug because it`s the easiest to get at). At plug in to #2 coil, there are three wires,Black(Ground?),Black with Yellow Stripe(12 volts) and Black with Red Stripe(This wire and seven others for each coil, evidently travel to Ecu). Well, I placed coil & spark plug near ground and am not getting any spark while cranking. FSM says to check coil resistance, which I did with OHM reading at .7 to 1 OHMs. The power transistor on 92 engine is different than the 94 SFM shows so I didn`t check this. Could I possibly have a fried Ecu which is causing no spark? Is there a way to check Ecu for this problem without engine running? Am I missing something else not to get spark?Any input welcomed