If you followed my post, i have a 98 pathy. Tranny took a crap and went kaput. Found the engine and tranny from a 98 qx4 so we swapped both engine and tranny from the qx4 to pathfinder. Should this all work Ill have a pathy with less then 90,000 miles on it! So the transfer case and adapter housing from the pathy stayed and the motor and tranny from qx4 went in with it! All the connectors were the same they are all connected the motors were both 3.3liter the tranny was a match had a hiccup with transfer case but solved that. Went to fire her up and we had intermitten random power at the distributor then we had none. Nothing NADA zip. There is no continuity from the eccs relay to the dIstributor, no power, no ground. No nothing. There is power from ignition switch to e ccs relay but thats where it ends. With the ecs relay pulled testing the wires there is nothing. What are the chances the ecm is fried? Would the ipathy ecm work with infinity sensors? We kept the pathy harness and everything plugged into the infinity engine harness, all connectors matched up and plugged in but ecm pathy be co.patiable with infinity sensors?Where do we go from here.

Wow, I saw the title of this post and I was, like, "Hmm, wasn't the Pathy Hybrid only in 2014??"

The ECM has to turn on the ECCS Relay -- basically enable itself -- so it only takes one misplaced wire in the ECM connections to screw everything up. It's almost always a bad idea to graft a different MMY engine into a car without either swapping the ECM or just using the long block and swapping all the other hardware. You can go pin-by-pin over the ECM reference charts in the FSM's for both vehicles and reconcile the differences, but that will be painstaking and you may just end up discovering there's some irreconcilable difference and you already blew something up. I'd recommend getting the QX ECM and reconcile the truck to that, rather than trying to reconcile the Pathy ECM to the QX engine wiring. There will be a lot fewer wires to worry about when doing it that way, and you can always get the QX ECM reflashed with a different program if something like the AWD is causing issues.

PS - If you don't already have the QX ECM, your best bet may be finding out the part number for a 2WD model QX (if they made one) and getting one of those, that will obviate the auto/manual transfer issue right from the start.

I had helped out another NICOclub member on a "mysterious ECU" issue and discovered a possible related cause to the issue here. topic626565.html#p6807768
Nissan had made changes to the ECU wiring pinout configuration on my '02 Pathfinder but those changes are not reflected in the factory service manual. The only issue I was looking at was specifically regarding the IACV wiring to the ECU. What I found is that my IACV wires do not match up with where the service manual indicates they should be in the ECU connector. The wires were there but they were in different pin locations in the connector compared to the manual. It's possible the pinouts are not matching up with this swap. A very close inspection of the wiring colors enabled me to find exactly what the difference was since some of the wire colors did not change, just the pin locations at the ECU connector changed in this updated configuration that Nissan did not document in the service manual. There may be other component wiring changes as well but I never looked at anything else, other than the IACV wires. Since they did this on my '02, Nissan/Infiniti may have done this on the '98 models as well with any updates that did not get documented in the manuals.

Here is the update.....still not firing. There is no power at the 6pin distributer or the 2 wire plug to coil. Crankshaft position sensor first the book says 570 to 630 ohms of resistance the old one was 1.9ohms and the brand new one also 1.9ohms and the harness that it plugs into has no power and there is no power at the excite wire at e ccs relay. We are majorily scratching our heads. Anyone got any thing else to try

I don't want to make you sort through too much, but look at EC-108 here:
https://www.nicoclub.com/service-manual ... 8%2Fec.pdf

The ECCS Relay feeds both the injectors and the ECM on separate throws. The pin 3~5 throw feeds the injectors, the pin 7~6 throw feeds the ECM, and the same fuse #62 feeds both the relay coil and the 7~6 throw. Note the "SSOFF" wire running into the ECM. That wire grounds the ECCS Relay coil, it doesn't power it. So, with the key off and the relay removed, you should see power on both W/R wires. If not, check fuse #62. You should also see power on R/W (the injector supply). If not, check fuse #63. Those fuses are all in the Fuse & Fusible Link Box under the hood, not in the cabin fusebox. You can find the fuse layout here on page 4:
https://www.nicoclub.com/service-manual ... oldout.pdf

If both fuses have power and are both good, but there's no power at the relay, you almost certainly have a harness conflict. If there's power at the relay where it should be, then put a test lamp across the coil terminals and turn the key on. The lamp should light when the ECM tries to turn on the relay coil. If it doesn't, same deal -- you almost certainly have a harness conflict, and in this case, it may have killed the ECM.

I'll just point out that the reason swap harness guys get such big bucks is exactly because of these kinds of situations. Plug in wrong and blow up, and all that takes is one crossed wire.

Thanks ya all you've defiently helped us. Im curious there's places on ebay that test and repair ecms, I wonder if they could set it up for the swap that we did or if ya all know of a company that I could call?! If not I am grateful for all the advice and troubleshooting. Ya all are awesome!

There's nothing to stop you from doing the same things a swap harness guy would do. Namely, go over every ECM and TCM pin in both FSM's with the printouts side-by-side and make a list of differences. Then make a list of all the wire-to-wire interface connections between the "E" (Engine Room) and "F" (Engine) Harnesses and reconcile those from the wiring diagrams. Then move the pins around and make extra connections as necessary. This won't be an exercise like making an LS3 harness mate with a Maserati, you already know the connectors match up. It's tedious, but that's what you need to do.

Hey were really having an issue with the ohms reading on the. Crankshaft position sensor anything you can tell us?

https://www.nicoclub.com/service-manual ... 8%2Fec.pdf
See EC-268, 166.5~203.5 ohms. BUT, the crank sensor can't prevent a VG30 from starting. Only the cam sensor can do that. See EC-264. The CKP is used only for diagnostics, not for engine control. VQ35's and VQ40's are another story, the control system is very different.

So can I just borrow you for awhile? You are kinda handy and smart about the nissans! Just kidding but I am very grateful for you sharing your wealth of knowledge

Sixty-plus years spinning various forms of wrenches and electrons teaches you a little bit (provided your brain survives. I think mine did).

You're most welcome.

We are so close but they say you should feel or hear the injectors when you turn the key.... Not hearing or feeling the injectors kick on. Everything is checking out except that. We've teste all the connectors and follow all the wiring. We still have intermitten spark and its strength is inconsistent and no fuel injectors is there any other suggestions you can think of? Again your knowledge is very appreciated....

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Intermittent injectors and spark can't be caused by dead components, they're always the result of the ECM not knowing when to fire them off. On a VG that signal comes from the CMP wheel in the distributor. So if you have power everyplace in the system that should have power, it may be that your new-old engine has a crapped wheel or bad distributor bearings.

UPDATE!!!!!!! Vstar you've gone thru this journey along side of us and fie that, I am eternally grateful. I thought you would like to know IT STARTED AND RAN!!!!! ThereIs still some fine tuning to do before she's road ready. But it is a step in the right direction, won't be long before she's drivable. The problem was the injector harness the Nissan harness has a 3rd ground the bolts to top of the intake manifold we left the infinity harness on the engine and it didn't have the 3rd ground wire at least not in the same place. Swapped those out and she started right up!

And drives frontwards and backwards!!!!

But she still acts like she is starving for fuel or getting too much. You can't put your foot in it cause she'll fall on her face, you have to gently feather the throttle and slowly talk her into it. I'm about to give up. She's been parked so long I don't know what else to do.

That kind of misbehavior is rarely fuel, it's usually air. Could be fuel pressure, check your regulator, but it sounds more like induction. Clean your MAF and make sure your IACV and TP are properly calibrated. Mdmellot can probably give you better help with that than I can.

The MAF was cleaned hadn't thought of the calibration that's next. And we're checking timing again. We were able to get another ecu is there any way to tell if it'll work on mine? The numbers on the donor ecu are KC MECM-W410-E2-8226 mine is B1 MECM-W430- E2-7904

The MECM-W430 is the Hitachi part number, the rest is extraneous. So that one isn't right. It may work anyway, but if it does it will be an accident. There are tons of used ones with the right number on eBay. Try to match the B1, that's a firmware code. The rest are usually date/qc codes and you probably won't find a match.

So the donor was a 97 Mines a 98 and it's a Hitachi part number? That confuses me...

Hitachi makes all of Nissan's ECM's and TCM's. You won't even find a Nissan part number on the outside of the later ones. The Nissan p/n is stored in the firmware. When buying a used one, you need to go by the Hitachi number.