So I just purchased an 03 G Coupe for very cheap to fix it and sell it. The problem is, the shift lever will move and display the right gear on the cluster, but the car does not respond. It does, however, engage park when in park and you can hear the engine rpms change a little bit when in reverse or drive. I haven't been able to find anybody with this specific issue. Before just ripping the transmission out I wanted to know if there was anything else I should check. The fluid level is fine and there is no noticable damage anywhere. The engine starts and revs perfectly fine and all fuses are good. If a new transmission is the only option, do I have to stay with 03 100%? I read that the TCM is located not inside the transmission on 03s and that leads me to believe it's wired differently. Thanks

 

Also, to add, there are no weird noises or codes or anything out of the ordinary..

 

Tow it to Nissan for a diagnostic so they can use Consult-II to read line pressures and look for problems, they will tell you EXACTLY what is wrong so you don't waste money throwing parts at the vehicle.

If you have an early '03 with the TCM located next to the ECU under the glove box then yes you need that exact transmission. Later '03's came with the same 5 speed Jatco that was used through the rest of the G35 lineage.

 

Probably will have to end up doing that. I was hoping somebody may have had this issue and known something. I don't think it could be TCM since it shows the gears and when i unplug it the car knows. Don't think its shifter related. Probably is transmission unless I'm missing some form of troubleshooting.

 

Usually you would have a low line pressure DTC associated to not being able to drive from no pressure (super low on fluid) but it could be something like broken shift linkage or something. The vehicle might think it's in gear due to the position of the shift assembly but the transmission itself is actually NOT in gear, with the door open can you listen under the vehicle and HEAR the transmission linkage moving through the gears? Normally the shifter would have almost zero resistance though and you would know something is wrong.

You are checking the transmission fluid with the engine running yes? I know you can't do a proper check since you can't physically move the vehicle but I would at least let the engine warm up, put it in gear, rev it high a couple times to uptake as much into the torque converter as possible then put it in park and check the fluid (engine still running).

If you are cold checking the fluid with the engine OFF that might be the problem.

Beware however, when you get it in gear and rev the engine it might build up enough line pressure and launch the vehicle so keep your foot on the brakes when doing this.

 

I'll give that a look. If that is the issue I think it would have to be on the transmission. Everything up top looks okay. & I checked it cold. I just made sure there was fluid in there, but after looking at some videos, if I remember correctly, mine would have been way overfilled. Would this cause an issue? I'll verify tomorrow after work that it actually is. I'll ler it run for a while. I wish I had more information about what happened to cause this. Hoping it's simple still. Fingers crossed.
edit: I do hear something when I let ofd the accelerator. I need to buy some jack stands because it may just be exhaust rattle. Sounds more like that. Sorry for the vague information. I'. At an apartment complex and still need to purchase a garage. Can't be working in the parking lot.

 

Okay I checked the fluid level hot and it is WAY too full. Would this cause the issues that i have? Should i just drain a little out at a time to get to the right amount?

 

Even at fully warm, the dipstick shows there's 3 or 4 times what should be in there..

 

I'm not 100% sure but it wouldn't hurt to drain it out into a clean container then add back the 4 or whatever quarts needed.

 

So i drained it and replenished with matic S and still no change. I have a new TCM on the way.. I'll give that a try first. If that fails then it's transmission swap time. I checked my dipstick after refilling with 5 qts and it still was very very overfilled. It seems as if the fluid isn't moving anywhere perhaps..

 

If fluid isn't moving AT ALL it might be a failed torque converter.

 

If I'm going in that deep I'll just swap the trans I suppose. I found this one on ebay. I'm 90% sure it would be compatible. The date on the car was 10/03. What date did they start putting the tcm inside? Can anyone else confirm that this one is compatible before i order? https://m.ebay.com/itm/04-INFINITI-G35-COUPE-2DR-AUTOMATIC-TRANSMISSION-FROM-10-03-RWD-/322361496266?_trksid=p2385738.m4383.l4275.c10&_mwB anner=1

 

They were actually kind enough to include the vin too if that helps determine. :JNKCV54E94M823654