VK45DE ECU start

Discuss topics related to the VH41DE, VH45DE, VK45DE, and VK56DE engines.
Richter12x2
Posts: 26
Joined: Wed Jan 09, 2019 1:00 pm
Car: 1955 GMC Pickup

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I'm working on installing the VK45DE into a classic pickup, so I don't have the benefit of all the supporting electronics and wiring of a Nissan recipient vehicle. What I'm trying to determine (or confirm!) is what is needed to power the ECU and make the motor run beyond the motor sensors. At this point I'm also fine with open loop mode, just as long as I can make it turn and start:

What I'm seeing from the wiring diagrams I've found so far:

Main ground to Pin 1 on the ECU
Ground also to 115 and 116 - is this fine to be a direct path to ground as well?

109 is switched power (from ignition switch, or whatever - only hot when ready to go)
It looks like 119 and 120 get power from the relay when it's energized,

The diagram shows 111 in the same area with the positive voltage, but color code and diagram make it look like it's actually a negative ground path for the coil - does the ECU provide the ground path for the relay on this when it feels +12v on 109?

I appreciate any help/confirmation!


Richter12x2
Posts: 26
Joined: Wed Jan 09, 2019 1:00 pm
Car: 1955 GMC Pickup

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Oops, I'm wrong - the Q45 has a different ECU from the diagram that someone posted a year or so ago for the FX45. The FX45 had a LOT fewer pins.

Looks like I need ECU to ground at 156,159,165,168.

It looks like power needs to go to 163 and 166, and pin 12 provides the ground path for the ECU relay - which rather than use a special Infiniti relay just to get two circuits switching off the same input, I'll probably split into two standard relays. 163 is relay switched circuit 1 to the ECU (and several sensors) and the second circuit provides for several other sensors.

Looking through the ECU pinouts, I see a LOT of references to Accelerator pedal position sensors, but looking at the Q45 accelerator pedal, it looks like a regular accelerator cable setup, especially from the engine perspective. I don't see where a sensor would go on that. Does it require some sort of sensor there? Or is just a provision for a drive-by-wire throttle setup for the future or for other applications of the ECU?

Yellow4g63
Posts: 3718
Joined: Mon Jan 20, 2003 6:07 pm
Car: 95 RB20 240, 91 NX2000 VE power, 95 Stock 240sx
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You might need to get it flashed for the immobilizer in the stock ecu.

Richter12x2
Posts: 26
Joined: Wed Jan 09, 2019 1:00 pm
Car: 1955 GMC Pickup

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Thanks, I'll keep that in mind!

nisjeep
Posts: 3
Joined: Fri Jul 13, 2018 9:32 am
Car: 2002 Patrol GRX 4.5
2001 Terrano II 2.7tdi
Location: Cape Town , S.A.

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hi Richter
How did your engine/ecu combo end up working?
I have a JDM import VK45 going into a 1980 Datsun Safari.
Having a hard time with all the secret squirrel wiring.
Where did you find the ecu pinouts?
Thanks

Richter12x2
Posts: 26
Joined: Wed Jan 09, 2019 1:00 pm
Car: 1955 GMC Pickup

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Sorry, not sure why I didnt' get a notify on this, or else I got one and was too busy to respond. Project was on hold while I gutted and renovated my master bathroom, but now that it's 99% done I'm getting wound up on the truck again.

The pinouts I got from the factory service manuals, available right here on nicoclub, although it's not super intuitive WHICH manual you need, the manual itself has a ton of info

https://www.nicoclub.com/FSM/M/2004_M45/

You should be able to find what you need between the M45 and Q45, but probably not the JX45. EC is a good place to start, because it SHOULD be "Engine Control". There's a section that tells you about specific sensors and the pins they use, and a large area for pinouts. The gotcha is, some of the stuff is done in different places and communicates to the ECU via CANBUS. That's the problem I had using the factory gauges (can you imagine how cool it would be to have a functioning M45 cluster in a '55 GMC?) I ended up going to a GPS speedo set from Speedhut instead, although I WAS able to get the trip meter working. (Took it for a ride with a 12v battery a pile of alligator clips and a GPS receiver in another car)

My starting point, just to see, is to find where to apply ground and where to apply 12V, use the factory ECU and transmission computers, and see what happens. It SHOULDN'T know at that point what car it's in, although I expect that I'm going to end up in limp mode when it doesn't detect the passenger side electronic motor mount or the side parking light or something. It'll at least be interesting to play with even if I eventually end up with a Haltech or something. It's a truck, so I'm not intending to race it, mostly use it for parts trips, or local car shows so I can give the SBC people something to complain about.

Richter12x2
Posts: 26
Joined: Wed Jan 09, 2019 1:00 pm
Car: 1955 GMC Pickup

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Here are a few pics from this week, when I really started in earnest again:

Image https://photos.app.goo.gl/8KLejQtuUHJgYxgi6

Image https://photos.app.goo.gl/xJk19e6vzAWuFJnF6

Unsurprisingly, I had to remove the i6 transmission cover to get height for the transmission:

Image https://photos.app.goo.gl/FzTMiK2BnwT5pbGz5

Fits nicely between the frame rails though:

Image https://photos.app.goo.gl/7Tw9YWSHNjavZMoj8

With the transmission cover off, it slid back right where I wanted it. The only modifications so far, is rerouting the transmission lines for the auto-trans, and I probably won't be able to get to the oil level sensor in the front anymore, so I'll probably have to bypass it for the ECU. The only substantial modification is that I'll need to take about an inch of height out of the middle crossmember, because it fits now, but has less than 1cm of clearance on the rubber driveshaft mount.

Image https://photos.app.goo.gl/kYGAGUK2mySPAR43A

I'd be really encouraged how well it fits, if I didn't figure this means it'll be a freakin' beast to get running right.


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