Code P1757

J

Jval

Member
Car
2005 FX35 AWD
Name
JV
Hello Forum, driving back from work, the check engine light came on at a traffic light. When the light turned green and I stepped on the gas the car was very slow to start moving. As I gained speed the car felt normal, but on each traffic light or stop sign I felt the same symptom. No other lights are on.

When checking for codes, I got P1757 Front Brake Solenoid Valve Circuit. Harness or connectors - The solenoid circuit is open or shorted.

I went to google and found this part is in the transmission. Is this DIY?
 
That sucks. It's on the valve body. It's a dirty diy, or should I say oily. Get a few rolls of paper towels, a large catch basin, 8 quarts of trans fluid but 1st, find out where you're gonna get a replacement. You might find the solenoid. If you do, it'll be a used unit that's been tested to work. I don't think you'll find a new one. Worst case scenario you'll buy a rebuilt valve body. $500-$600 depending where you find one. Some with lifetime warranties. Good time to install a shift kit. :)
 
Have you done this job?
Do I have to test voltage or just replace with a new one?
Is this the part?

Screen Shot 2018-10-08 at 10.43.29 PM.png
 
I did do this. I botched it too. Quit smoking and installed a shift kit a couple days later. That was a really bad idea.
Anyway, you'll want to make sure it is the solenoid and not something pissing off the solenoid. Auto transmissions are things that even the performance shop I've frequented will not touch. Go to most average service shops, even those that pull engines, and they'll kick you in the nutz for even suggesting they touch it. What I wrote above is about the full extent of my knowledge on this subject. I'm sure there are others on this forum that know more but not so sure you'll get a response.
 
So I took the car to a transmission shop. They got error codes P1757 and P1759. Both are related to the transmission solenoids. They call me and said I need to rebuild the transmission at $3k tune. I asked them how they came to this conclusion and they simply said that when they see those codes it means rebuilt is the only option.

I asked why not replacing the solenoids or the valve body and they said they can try that but will not guarantee to work. I towed the car to another place and they told me the got the same errors but the only way to get a good diagnosis is to open the transmission and take a look. Charge to look inside is $800. The tech said he thinks is the torque converter. I asked why if the codes are relate to the solenoids and he said that's what they usually find.

I've been reading a bit more about this car and symptoms of a failing torque converter are slipping, hard shift, overheating, shuddering, dirty fluid, stall speeds or weird noises. I had none of those.

Any thoughts, ideas and advice are appreciated.
 
You could try John at IPT (Import Performance Transmissions). He's one of the owners and the one who will answer the phone. They build performance transmissions but also bail out dip shits like myself when we go off the rails. He's extremely familiar with our transmissions and helpful. You could ask fr his opinion as your next step.
I've found that when a code comes up for a sensor, it's a sensor. You've got some solenoid codes so I'd be willing to bet it's the solenoids. Do a search and you'll find working, lifetime warrantied valve bodies that have been pieced together from multiple "broken" valve bodies for $500-$600. If you go this route, make damn sure it's the right valve body. There's a diy on this forum for a shift kit install, so that and/or the FSM will help you give the transmission a heart transplant.

Do you have coolant in your transmission fluid or vice versa? If so, GTO on this forum had the same problem which did necessitate a rebuild. The glycol in antifreeze really fucks up the works. :tdown:
 
Great info. I don't think I have coolant, I didn't see any contamination in my radiator or reservoir.

I've been searching for the valve body and found many different versions. Thanks!
 
If it is contamination, Coolant would probably be in the oil. The coolant can and would ruin the clutch bands in transmission. Hope that's not your issue, but that is basically a rebuild. Torque converter rebuild likely can be done at same time if in there anyway.
 
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I almost forgot to mention there's programming involved with the new valve body. One or 2 of the co's that make and sell these valve bodies include the programming iirc. If you go this route, call each company you find and ask questions. There's only a few. I believe you can also send them yours.

You'll want to know for sure whether or not this issue was caused by glycol. IIRC it'll cause issues as GTO mentioned above but it can also corrode the electronics in the v.b. If you're radiator is compromised and you fix the v.b. but don't replace the radiator, guess what'll happen?
 
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gto said:
If it is contamination, Coolant would probably be in the oil. The coolant can and would ruin the clutch bands in transmission. Hope that's not your issue, but that is basically a rebuild. Torque converter rebuild likely can be done at same time if in there anyway.
Click to expand...

Do you mean coolant in the engine oil?

I'm taking the car to a friends shop to open the tranny and test the vb.
 
Coolant in the transmission oil. There's a trans cooler in the bottom portion of the radiator, so the two coolers share a wall. GTO got an aftermarket transmission cooler after his rebuild.
 
Finally got time to take the valve body out. Fluid was a bit brown but not too bad. Found some metal shaving on the pan but seems normal. The remaining fluid drained after I removed the VB was nice and clean.

The VB looks really clean and shiny, I don't see any corrosion or rust. When I have time I will open the VB and TCM and check all the solenoids. I also drained all the coolant and it looks clean. I'll post photos of the VB tomorrow.
 
ll the solenoids came out pretty easy. That's a good sign.

I just realized something thou. The tranny fluid did smell sweet, I thought it was normal, but I still have some unused ATF and it doesn't smell this sweet. The valve body loos very clean though.

See pics.


TCM-Top.png VB-After-Removal.png VB-No-Solenoids.png VB-Detail.png VB-No-TCM.png TCM-Underside.png
 
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I opened the TCM and found the broken circuit triggering the error code p1757 and p1759. There are many vids in utube showing how to look into this. I will have to find a computer repair shop to solder the broken circuit. Look at this video at 1:28 to see my issue.



I'm uncertain about something thou. See these comments and please comment:
  • The drained ATF fluid had a bit of a sweet smell
  • The color of the drained fluid was brownish and not clear, kind of dense, but not strawberry milkshake color
  • Last time I drained my ATF, the color was brownish/red but kind of clear and a foul-ish smell (about 20k miles ago)
  • The new tranny fluid (Valvoline) has a bit of a sweet smell when new
  • I mixed new Valvoline ATF (nice and clear) with new green coolant, and the mix became bright pink and dense, not clear anymore
  • I drained the coolant and it looks clean
  • My coolant level was perfect. I'm assuming if coolant is going somewhere, my coolant level should be low
  • The VB, solenoids and TCM looks clean. No rust or corrosion.
Is there a specific way to test the ATF fluid for coolant contamination?
Is there a way to see if the radiator is leaking coolant into the transmission? Disconnecting the tranny lines maybe?
What do you think? Do I have contamination or other parts going bad inside the tranny?

I will solder the circuit, put everything back together and test it, but I'm interested in your thoughts regarding the radiator and possible contamination of the fluid and tranny.

Thanks!
 
Oh shit, I forgot about the circuits or "buses(?)" braking like that. That'll save you time & $.
Glycol contamination is not common in the FX. It is in Nissan trucks & mini vans. It does happen though, per GTO. It doesn't appear as though you have that issue. You found your problem.
The valvoline atf you've got is clear? The Val. synthetic that's good for our trans and transfer case is red. Not to say what you have isn't as well, idk, but I know the Val. Max Life full synth. is good to go. Got that :poop: in my power steering system also.
You could pick up a Transgo reprogramming kit for a couple hundies while the v.b. is out. You're 90% the way there, just a few springs, check balls and holes to be drilled. Just watch the main pressure check ball & spring, better yet, just leave that :poop: right were it is cause it doesn't need to come out anyway.
 
Valvoline Max Life is fine for our transmissions? I've read many places that it's the same thing as the Matic S; but, lots of people are hesitant to use something else other than what Nissan supplies.
I've yet to hear of any transmission failures from using the fluid.
 
g0ldm4g3 said:
Valvoline Max Life is fine for our transmissions? I've read many places that it's the same thing as the Matic S; but, lots of people are hesitant to use something else other than what Nissan supplies.
I've yet to hear of any transmission failures from using the fluid.
Click to expand...

By in large, people have been worried about using whatever fluid in whatever make and model for whatever purpose forever. There are fluids one shouldn't use, for example, certain coolants in our VQ35DE's because they'll corrode the interior of the engine.
The Val. Max Life is fine and might be part of the reason why my transmission is a bat shit crazy tire chirping machine. IDK but no problems for me.'
I'm glad you found this forum because this broken bus issue might be your problem as well.
 
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