This last part is part of why I posted. I did a search and wasn't able to find anything.

If I had just gotten a used transmission, would I needed to chip it?

I live far from work. Part of why I bought a comfortable car.

I have a very old (1962 MGA) car that I mess with on weekends, but I'm not about to drive that to work. It doesn't even have a top or locks.

 

Sounds like a **** shop, I would never go there for anything. If they don't know how to look up service information and follow semi-detailed instructions via 1 of the 3 widely available tech resources (Mitchell, Prodemand or Alldata) every shop SHOULD HAVE IN 2021.

Not only that, but the 2 most commonly used Tech level OBD2 Scantools (An Autel Scanner or the Snapon Solus) would be able to diagnose this issue in the standard 1 hour diagnostics fee they slap you with right off the bat. I am still trying to figure out how the repair was $3,400, this is, at most, in my 2 ASE Certification knowledge and automotive trade-school based education, This should have been cheaper by about a thousand bucks at any reputable repair shop. If you can please, if you are comfortable, post the invoice? I am currently engaged in ethics courses as part of my bachelors degree for automotive and would like to see where they might have "put the moves" on you.

To answer your followup question orava, unsure what "chipping" is, but I think you are referring to "Module Programming", If you were to replace the entire transmission (NOT THE VALVE BODY, which is the part you had replaced) the ECU -could- need transmission info resetting (but I THINK, this is the same as disconnecting battery and resetting Adaptive Shift Strategy settings) for the estimated transmission clutch, band and assembly wear so that it can have proper default shift settings. I searched the service information I have available to me for about 15 minutes and could not directly find mentioning of a module reprogram step for either the TCM or the entire 7AT. I am fairly confident in this answer. I can give you the entire R&R for the 7AT or the valve body if you are curious on this topic. I assume the reason behind this is your ECU holds the TCM programming, which will have baseline programming for the specific transmission (which I will assume you are replacing THE SAME PART NUMBER) you have.

The "programming" is shift strategies etc, which can and should be updated. Again, I did read the Service Information and my best information leads me to know that a new ECU will be sold blank and will need Transmission information programmed, but if you have a working ECU with working trans programming already, there is nothing to do but install the parts. I re-read the service procedure AGAIN to check and again I feel confident that you could just swap an entire transmission without any module programming.

 

It was difficult to find information on this to be sure. As you can see from my experience it was a lot of trial and error due to lack of clear understanding and incorrect compatibility information for me. A used transmission would have had to match the model (and date of manufacture in the case of newer than 02/13 models in my case) and would have worked fine... no re-programming required.

I may be wrong but the information available for Infinitis is mostly modding and improving vs. fixing for everyday use... when issues like this happen it's easier and affordable for those who drive them to simply replace and not worry about it vs. fixing themselves. I bought my 2013 G37 in 2015 used and had just finished paying it off last year... is a fantastic car and a joy to drive without monthly payments

 

Snaxxor... what I haven't included in my posts so far is the fact that my car back in Feb of 2020 @115k miles had the exact same issue... I didn't know any better and took it to the closest transmission shop where they proceeded to (according to them) pull apart the transmission and tell me it would need a rebuild which would be 3,200 dollars... at which point I said thanks but I'll look elsewhere and then the price magically got reduced by a few hundred dollars each time I had to get on the phone with them to sort out towing it somewhere else to where they said they would do it for 2,100 dollars. I mean seriously, if that's not blatant I don't know what is.

At the end of the day I ended up purchasing a used transmission for 800 dollars which I then had no choice but to have the shop where my car was at disabled without a tranny install the used one for another 900 dollars. Might shed some light on why I've spent the last 2+ months getting the "same" issue fixed myself that occurred again on this used transmission avoiding at all costs any shop or dealership.

Knowing now what I do now that tranny replacement took no more than 2 hours for a tech to perform after they put me in the position I was in where my original transmission was in pieces when it was probably just the valve body/tcm issue to begin with... no shifting/slipping issues before it all of a sudden just went into limp mode.

 

I paid $9,250 after taxes for my 2010 G37x with 87k Miles on it in 2018. I'll be the 3rd and final owner, I will drive her to 300k before I let it go.

I could never justify paying someone else to work on it for that price. I will admit there are some issues from the factory that suck if you got them, but all that in mind, the car is easy to work on, the parts can be cheap, and shes got 300+hp. I don't think its a better route to pay a dealership to work on an Infiniti, at the most I would take it to an independent shop and be very straight forward with your concerns and symptoms.

While it make take -SOME- time looking up, you can find for free on youtube or forums any FSM or repair how to.

Sometimes you need to look up specific things, for example, when I was tracing Original Poster's issue, I used the base name for the transmission and the DTC (Diagnostic Trouble Code) P0705. Since I know P stands for Powertrain and the first number is a 0 not 1, it tells me this is a general code, not specific to the manufacturer, I look up the code using google first and it tells me the code is triggered by the transmission failing to be in the right range due to malfunction. I next look at the situation you are in, vehicle turns on, drives, but is in limp mode, this instantly tells me its not the speed sensor because you are able to make the shift from 1-2 and 2-3 and obviously 3-2 and 2-1 (also P-R-N). I will suspect Transmission Range Sensor since I know you cannot shift ALL gears, but you have some, this tells me your vehicle can determine speed under load and attempt to shift accordingly. After looking into the Service Information, I note the locations of the suspected components and compare to more google searches, pushes me to valve body replacement. With the capabilities a car dealer has, they should have been able to figure this out and not oversold you.

 

Where were you 2 months ago...

Really hope this comes in handy for anyone else faced with this issue. Any idea why in my case it seems to be the actual valve body when you take away the solenoids and TCM from the equation?

 

Hard to say specifically, but digging around (hey im doing FREE diag work here!!!!) pushes me around in a few directions, if the Valve Body has a harness connector on it, this is most likely the culprit. There are however SOME pressure numbers you in theory could check, spools could have gotten stuck, springs can bind etc. They do give some values for pressure testing that you might be able to check with a decent scantool if the PID shows up for it, 1370 kPa perhaps, it shows up a bunch.

Theres a joint connector which coulda gotten ****ed up on a hard bump, overall the symptoms point to some kind of electrical connection being open or having some issue where the signal sent back is not right and making the car be in limp mode. Included a chart which you can check for electrical values to detect bad harness / connector. To check against it being the output speed sensor, theres a little test I didnt show here, but it will help you determine if its the speed sensor or OTHER ISSUE.

I do suspect highly a possible electrical connection fault, its all that they lead you to believe, however you said the old tcm and solenoids operate fine, my eyes are on the connectors themselves where they plug into etc. Two connector pins could have arc'd by some metal in the fluid passing by and made the readings from tcm not appear normal.




I forgot where I saw it, but it lists the valve body and TCM as non serviceable parts, meaning replace in entirety. It's probably why the remans are hella cheap and available, also the fix for majority of limping transmissions.

 

I have a 2013 G37 journey. Bought it used in 2019 with 50,000 miles on it it has 116,000 now. Car went into limp mode last week with a speed sensor code. Took it to three different places around Jax and they didn't want to touch it. How is recommended to take it to the dealer or to aamco, so I opted for the latter. They called this morning with the good news bad news vibe... Good news: transmission is fine. Bad news: it needs a valve body replacement and tcm module. Combine that with the reprogramming and new fluid, $4,900 out the door, tax included. Is this worth it? Am I getting ripped off?

The car is paid for. Blue book trade-in on carvana is $6,500 right now. Should I just bite the bullet and fix it and continue to drive it for a few more years? Or fix it and try to private party sell it for a higher amount? Or scrap it? Any feedback is appreciated. This is my first infinity or Nissan product. I do love driving the car. It's been a joy. But I've never been keen on high repair costs. So maybe I just need to get out of the Infiniti business. IDK