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Discussion Starter · #1 ·
Can anybody help me here? I have what seems to be a bit of a strange problem maybe. Or should I say not typical. Put a new Nissan cvt trans in my daughters car now and at 31,000 miles (on the new unit) it just decided it don’t want to go forward anymore. Got the dreaded P17F0 code but the belt and pulleys are fine along with no metal shavings in the pan. She says there was no noises when it occurred, only lunged and seemed like it was in neutral. Drives normal in reverse. My question is am I really looking at more of a valve body issue here? Can’t find help as everyone says P17F0 means new unit. But I feel in this case that may not be true. Obviously with Nissans wonderful 12 month 12,000 mile warranty on a new OE trans it’s got no coverage. I can’t find any info on testing solenoids or valve body function and no one local wants to offer up any info. Just a bunch of guessing parts replacers I guess. Only other thing I can think would be if there’s a forward clutch pack that took a dump, but again with the limited info out there I’m kinda lost. Not a cvt expert, just a normal auto tech. So I understand plenty but hate to throw another trans in this car so soon, or at all… and don’t want to waste the money on a valve body as a guess. Any help would be appreciated!! P.S. new trans was programmed and fluid level was correct
 

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Bad news, that's a snapped CVT belt. On the dual-range CVT in the Versa and Sentra, reverse is driven direct by a clutch using the planetary gear set, the forward gears are driven by the belt plus the planetaries. No forward motion means the belt is either in full slip or has broken and is laying in the pan.
 

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Discussion Starter · #3 ·
I pulled the pan and it’s clean, no metal. Also when viewing live data speed sensors for turbines (I have a snap on scanner and it was calling them turbine) but input / output shaft were bothe reading rpms in park and neutral but in reverse or forward with the brakes on both shafts go to zero. Let go of the brakes and starts reading rpms again.
 

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Discussion Starter · #4 ·
I’ll jam my camera back in the hole and see if I can get a better view of the pulleys and belt to see if I can find wear.
 

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None of the three sensors should be reading anything unless the wheels are turning. The input should also be 0 with the wheels stopped and the belt locked, and the torque converter will be in full slip so the turbine will be 0 as well. So that part is normal. If the output sensor is showing turns with the wheels stopped, that's a different story. I think the output sensor is right on the output shaft, so that shouldn't be possible, on or off the brake. There are 3 sensors, are you maybe looking at turbine and input, not input and output?
 

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Discussion Starter · #6 ·
I’ll double check tomorrow, car is on the lift so wheels and not being held unless brake is applied.
 

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Overfilling, even if it's just a bit, is a bad thing to do. The condition causes excessive foaming of the fluid which results in quick failure of the tranny.
The CVT fault code P17f0 CVT judder can also be caused by these conditions:
  • - Faulty Continuously Variable Transmission (CVT) assembly.
  • - CVT harness is open or shorted.
  • - CVT circuit poor electrical connection.
Before condemning the CVT unit itself, first inspect the electrical connections for tightness and make sure there is no oxidation on the pins. Have you checked the CVT to make sure the fluid is at the full level. If the fluid has a brownish appearance and has a burnt odor, then there is internal damage.
 

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Discussion Starter · #8 ·
Ok, so I verified the belt is not broken. I spun it around a few times while watching it with the camera. The pulley walls are not scored in anyway. Again, this car was driving fine and just quit when trying to pull out. I originally thought the belt broke (but did verify with scanner in live data it was in there enough to hold the shafts still in gear and they both spun if I let the wheels spun) and pulled the pan to verify, when I saw no pieces in the pan I pulled the sensor and took a peek with the camera. Everything in there looks as it should as far as I can tell. Magnets have normal amount (or so Nissan says) of fine debris on them but no metal shavings or chunks. I can’t see anything wrong with the harness or plug. I just wish there was more info out there for diagnosing. I guess I could be wrong but I feel something in the valve body is not working or sticking.
 

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I agree. That belt looks healthy and since the car moves in reverse, we know it can't be a complete hydraulic failure. Here's the operations chart for the RE0F11:
Rectangle Font Parallel Slope Pattern


The high clutch and reverse brake are on the same solenoid, high clutch is engaged when reverse brake isn't. So, since R works, the only possibility I see for component failure is the low brake solenoid. Mechanically it could be the low brake mechanism or a leak in the low brake hydraulics, but if you don't see any broken drums or clutches, try a VB.
 

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Discussion Starter · #11 ·
Awesome, that’s along the lines of what I was looking for. I’ll get a new valve body and let you know how I make out.
 
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