Hey guys.. I'm new to the forums, first time Infiniti owner - long time neglected car lover..

My newly acquired 2013 G37xS, mileage unknown but last odometer reading was 291,000 in August of 2024 according to the CarFax. Shop put a new used motor in it at 285,000. Paid $1,200 for it. It has been a while since I have taken on an aging and neglected budget-friendly pseudo-sports car with over a quarter million on it, but here - I'm willing to do it again....For better or worse.



I did find the fourth matching wheel in the trunk



This went up for auction as a repo and my customer bought it. It had no ECU, BCM, AWD module. He installed them, programmed keys etc and it would run for a half a second and die - when it actually cranked over. It wouldn't always.
He didn't care to mess with it further and I made an offer.

It's sat since October 2024 - so about 6-7 months. There was gallons of water under the carpet, all 4 corners. Windshield cowl was off and draining rain right into the cabin air filter all year. I'm no stranger to this problem, setup the 7 gallons/day dehumidifier, ozone generator, steam cleaned interior, shop vac etc - all the typical stuff. Dry as a bone after 4 days and a few steam cleanings. Smells like a normal car again, not bad.







But it won't start. It runs for half a second and dies - but ONLY if the Can Low wire at BCM is clipped (Previous owner's troubleshooting, thanks for the tip buddy). And the information display in the cluster doesn't show anything but a backlight. Gauges and lights work.

When Can L is out of circuit, full comm with ECU, BCM - perform NATS reset etc. Cluster, heater, radio, headlights, starter - it all works. It just dies after half a second, I am assuming because module downstream from this clipped wire is needed.

When Can L at BCM is connected:
• No communication at OBD port
• Electronic fan, climate control & headlights run constantly when IGN ON
• Ignition cannot be turned off
• No crank





Well, what is going on.. After doing some of the testing in the FSM for LAN, I found this Canbus L wire has continuity to ground somewhere.

I removed and inspected ECU, IPDM, BCM, AWD module, driver side fuse box/junction block. I unplugged every accessible harness. Tested the modules for resistance.
In the end I found the short to ground was the circuit in the driver junction block/fuse box which powers the instrument cluster. I found pin for injector #6 on ECU was rusted and missing, but it is not jammed in my current harness. Driver junction block is corroded. I disassembled it and it is full of dozens and dozens of pieces of metal traces which are circuit paths, all stacked and separated by a few plastic plates to keep them from touching. I think that one is the culprit. I bought another ECU & junction block, waiting to receive. We will see if it's JB or the M1 circuit on the JB. Disconnected it and cluster/push button stopped working. I am not sure if it powers the cluster directly or just the AC Meter.

FSM does not list the pins on harness M1. It is labeled as "WIRE PASS THROUGH" with no pin identification. That hung me up quite a few times. Pin outs on many harnesses and all modules are listed, but if the harness is labeled as a pass-thru... No dice. I was able to map out which modules use harness M1 on the JB by comparing/contrasting pages, but I did that on paper with hard copy.. Can't paste it here.





OFFENDING HARNESS



Anyway - There is very little rust. Front end looks tight. Steering rack leaks. Oil was good, good coolant. No leaks anywhere to mention other than the steering rack.

Previous owner unplugged the trunk popper and unclipped the emergency pull cord. I had to use a shovel through the rear seat to get the trunk open.
I am hoping I can actually get it started so I can shake down this mess.
I want to know how the trans fluid looks and how much metal in the mesh filter.
I'd like to know compression and see if the motor uses much oil.
I want to know if the AC still works!



It's covered in moss - Sitting since October 2024. I couldn't resist a quick cut and polish on one side while waiting on parts.




In the half second it ran, I didn't hear any knocks... Which just means there's no rod knock - but it sure could be knocking anywhere else. We'll see!

Anyway, thanks for reading my rambling. I'll get my parts on Saturday and we'll see what happens.



Ran a 7 gallons per day dehumidifier in it for a week, with a few ozone treatments (3hrs total). Steam cleaned. Shop vac'd. Basically, everything you expect to make it smell OK again. And it works! There's some things you can't recover, but if mold just starts you can usually get the smell out.. once it starts eating the foam and substrate, it's a goner. Decomposing is the nasty part.





Interior is in OK condition. I do have all plastics. All electronics work. Ripped apart driver seat and less than maintained, but at 300K I think it held up fine






Sold at auction with no computers behind glove box - AWD module, ECU, BCM, etc. My customer put in those modules, programmed keys - it didn't start... so I happen to see my customer listed for sale and made an offer!



When Can-L disconnected, ignition turns on and it all seems to work, except for the info display. No idea what the mileage is yet! My Autel could not display that...

 

I have a 1 year update! i fixed the no start after much diagnosis and research on the hitachi tcm, canbus and harnesses. The 7AT did get a new valve body, new solenoids, i repaired original tcm, and now it shifts great.
It needed cats, sunroof drain fix, fuse block driver side kick, much wiring diag and repair (including MAF pins at ecm, tcm, ipdm).
I put in a new rad, hoses, front brakes, front cv axles as well.

I have so many hours this last year, a lot of drama related to diag of many issues - many twists and turns, but I managed to get this running excellent and looking good too! ive been daily it this spring.

It was no less than a basket case, but it is living its best life now and I hope to hit 400K miles with it! note, it has a motor swap but trans is unknown mileage


I wrapped this in KPMF Indigo Blue with a carbon fiber black hood. I have done a ton of work this last year on the 292k mile auction car. I found it had a low mile motor swap. Trans shifts perfectly after all of my work, but has unknown mileage.

No start, no comm diagnosis: The starter+12V shorted to Can Low inside of the metal circuit traces in the TCM and also within the transmission tunnel harness. Two separate repairs without issue.
[img alt="I had to bypass 2 pressed circuits in the TCM ti restore communication - has been working for a year now!
Soldered from cpu pin to the harness "]https://cimg8.ibsrv.net/gimg/www.myg37.com-vbulletin/2000x1504/20260605_085717_4e8d3381e3d40c307253bf5b8426c49971 7b16a8.jpg[/img]
I had to bypass 2 pressed circuits in the TCM ti restore communication - has been working for a year now! Soldered from cpu pin to the harness

This is a lower mileage donor valve body and reman solenoids. I was getting a TCC pickup code intermittently, so I got the solenoids. I have no clue what vehiclethe tcm or the valve body is from. I cloned my original tcm data on bench over to the donor tcms.

Here we see 3 TCMs. One is my original i repaired. One is a random used one, bad input speed sensor. I bought them all untested on ebay. The other came with the random used valve body. I cloned my original TCM to donors using obdstar. I did have to install one to find out it had a bad speed sensor. I will practice replacing the ISS with a random sensor from china, they are available for the hitachi unit.

My trans used to have a 2 3 shift flare. My repaired tcm worked great. I tore down the original valve body to find the tcc and 2 3 circuits were bleeding pressure out between the valve body separator plate. This is what prompted me to go with a donor valve body from an unknown vehicle. Good $70! It shifts perfectly now.

My original cluster had a dead screen. I got a low mileage donor and mileage corrected it. When i bought the car, i couldnt see mileage and i couldn't read it because obd had no comm.

Read the chip, upload file, pay the $5 and get a file with mileage corrected. Note: you cant hex edit the file to edit. I found 3 memory addresses with mileage and changing them did not work, bad checksum

I did get new tires. It had a spare on the back when i got it. Luckily the last Drift wheel was in the trunk

Also tinted fogs while i was in there

Added duck bill
[img alt="There she has sat for hundreds of hours with me.
There is a lot of work not listed to get this road ready again"]https://cimg0.ibsrv.net/gimg/www.myg37.com-vbulletin/2000x1504/20260505_214343_3a4a6741c4c2b1f78fd146a280667c1e36 382997.jpg[/img]
There she has sat for hundreds of hours with me. There is a lot of work not listed to get this road ready again

Old solenoids. Car has 290k, low mile vq37 swap by a shop with paperwork, but trans had unknown mileage

I retrofitted halos in the stock housings and painted the reflectors black

Trakmotive front cv axles. The old aftermarket axles looked freah but shook SO bad on the highway

 

Looks like i need to dig on the pc for photos.
Here are a few more from the last year



The headlight retrofit

New tires. Polished and coated the wheels.

3D printed threaded center caps. Painted calipers and brackets.

There is the shorted out trace in the tcm

Early days of bench testing for communication! Ive gotten pretty good with these tcms.

Duckbill spoiler and the lip on the windshield

Tcm spider 😂

Interior cleaned up nicely. Added carbon fiber accents, mainly to hide the peeled chrome finish