My G35x threw codes p1757 and p1759 on Friday, which point to the front brake solenoid valve. Trans (5AT) fluid is clean, no functional problems prior to codes (now locks in 3rd gear due to codes). I know next to nothing about transmissions but have read through the several threads here over the years about this problem.

It seems that most people swap out the transmission since Infiniti doesn't offer replacement solenoids and the valve body is expensive ($1500 with gasket and tax). In addition, the solenoid was changed during the '05 model year and Nissan transmissions don't work in the '05. Consequently, unless you really know your way around transmissions it seems best to replace the transmission with the same part number.

A couple people have suggested or had success with simpler fixes such as finding someone who modifies valve bodies and can replace the solenoid, or having a trans shop inspect the trans fluid for metal shavings and if it's ok put in a new valve body with a warranty. Meanwhile a local Infiniti dealer has offered to put in a used transmission with 97k miles for $1500 part and $900 labor. There would be a 6 mo. warranty on the part (with the original seller, not Infiniti), no warranty on labor. The most highly recommended trans shop in the area wants over $4k to rebuild it, which is ridiculous.

Any advice or suggestions would be greatly appreciated. In case anyone knows of local resources, I am in the Philadelphia area.

P.S. Some discussions of this problem have referred to a Transgo valve body or or shift kit. I can't tell whether this would be a practical solution to my problem.

 

i was in same boat as you but i have RWD. My issue was the valve body. seems like there was an issue with it but nissan never acknowledged it. either way, only solution i was able to come up with was to get a junk yard tranny from LQk and swap it. I was not able to find a new valvebody and did not want to spend 2k from dealer for it. You can find a used transmission and pull the VB off it and put it in your and just keep the other tranny for just in case.

I could not get the shop to fix my VB since they could not get new solenoids. I really dont know if the oem ones can be fixed or clean but that seems to be one way to fix it.
either way, upgrading the VB requires your existing one to work since only thing is done is spring replacement.

 

i spoke to a friend at a tranny shop and he said the issue can be with the computer and part of which is in the tranny. There is a motherboard that would need to be swapped out. He said the main symptom of having to change the board would be if the car hesitates to take off in first.

 

problem is that the computer is attached to solenoids and its a dealer part only, unless you buy a junk yard transmission and replace the ecu into your tranny.

 

I saw a video about someone fixing the valve body in these transmissions. Basically, there is a metal pin that becomes loose. Some solder and time and it was fixed. Google RE505A transmission fix or something.

 

Hey y'all. I just got the same code, P1757, popped up on my '05 G35 sedan RWD. I took my car to O'Reillys and ran diagnostics on it. He said try and drain and fill on the tranny first, sometimes the solenoid can get stuck. Not sure if he was bs'ing me or what then if not, it is definitely the solenoid or valve body that needs to be replaced. I have only done minor driving as it occurred this evening. It hesitates coming out of first. Prior to this event, I drove through a puddle after a decent rain. Could water have gotten into the trans and flipped this? And more importantly could a drain and fill be a viable option?! Any help is greatly appreciated.