tja623 wrote: ↑Mon Feb 09, 2015 3:39 pm
Well I got the dreaded P1757/P1759 DTC. What a disaster!First off, I own a 2006 M35x with 135,000 miles on it. I am an automotive technician, but I work at an indy shop that specializes in European imports, so my experience with the Infiniti brand is limited. Anyway, I am on the way to work and all of a sudden acceleration is weak, check engine light comes on and I feel like the vehicle is in limp mode. I get it in to the shop and start pulling codes and running diagnostics. It seems to point to the front brake solenoid. Of course , to my dismay, single solenoids are not available, they only come FREE with a new valvebody! Lovely, Infiniti of Annapolis charged me $1180 with a $200 core charge.
So i get the pan dropped, swap out the valvebody, fill it up with new fluid, and take it for a spin. Now the tranny is WORSE!!! And I'm getting upset. So I call Infiniti and ask them if the TCM in the valvebody needed to be programmed. Their response,"Oh yes, bring it in, all of the modules must be updated and programmed", Cost $135. So I drop it off, only to get a call later saying the tech has to make sure I installed it correctly before he wastes any time on programming the TCM. I went back and forth with the idiot and finally gave in and said to go ahead and check. 20 minutes later I get the call, Yes the valvebody is installed properly, BUT I need a new transmission! Needless to say I disagreed and said I will be there in ten minutes. I show up and the tech brings me back, and asks me if the shop rags we use at my shop are RED. I respond "YES?"... "WHY?"...he says " oh you can use those rags to wipe off the pan and tranny where the gasket will be placed because it ruins the transmission." He says,"We call it RED DEATH!" I call it "BS!"Then he went on to say that there was some metallic flakes in the bottom of the pan, and that further supported his diagnosis. I responded with" that is impossible, the flakes are not stuck to the magnets, therefor it is aluminum and likely came from the case. Internal tranny parts are steel and clutch material and it would stick to the magnets if something internal had worn excessively." The dumbfounded look on his face told me that he didn't know what I was talking about, so I tell him to button it up and return my car immediately.
In doing so, I find out the valvebody TCM does NOT need to be programmed at all, it is a plug & play item. So why was it there in the first place? Because the idiot on the phone really was clueless! Another reason I hate dealerships, they always have a service writer who doesn't know anything about the vehicles.Talk about frustrating!
Now I'm still stuck with a car that has a wacky tranny. I try and do as much research as possible, but everything points to the valvebody. I even went as far as just swapping the bad solenoid out to see if that would work, but nothing came of it. I checked continuity/resistance on all the solenoids, both new and old, and the all matched. That fact stuck in my mind , like maybe the solenoid actually isn't bad, maybe its the TCM or ECU? At this point Infiniti won't return a used valvebody, but they would warranty the valvebody. So I figured I would do that and at least I would have a new valvebody to sell on eBay and get most of my money back . So I park my ride, post the new valvebody on eBay, and wait.
About 3 weeks go by and the lead tech at work says to let him take a look at it. Of course, he comes up with the same diagnosis I came up with, it needs a valvebody or computer. So, reluctantly I open the warranteed valvebody, installed it, and VOILA! The tranny worked perfectly! Turns out I got a bad valvebody in the first place! It either had a bad computer(which is very likely) or somebody swapped out a used valvebody and returned it as new. Or maybe it got dropped, I don't know for sure. But I do know I didn't need a new transmission. I've put about a thousand miles on it since and haven't had any issues.
In closing, I do think the TCM's go bad in these valvebodies, and they throw false codes. If anybody needs some solenoids, just hit me. I still have the old solenoids as I returned the core without them. Just a little thank you for all of Infiniti of Annapolis' help! HA HA HA!