# 2014 Nissan Sentra P17F0 help



## TerryG (Jan 13, 2022)

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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## VStar650CL (Nov 12, 2020)

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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## TerryG (Jan 13, 2022)

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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## TerryG (Jan 13, 2022)

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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## VStar650CL (Nov 12, 2020)

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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## TerryG (Jan 13, 2022)

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


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## rogoman (Dec 16, 2004)

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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## TerryG (Jan 13, 2022)

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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## TerryG (Jan 13, 2022)




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## VStar650CL (Nov 12, 2020)

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:









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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## TerryG (Jan 13, 2022)

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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## TerryG (Jan 13, 2022)

Just figured I’d pop back in here and give an update. We had some snow in my area and parts delivery took longer then expected and my shop was full of customer cars. However I got a new valve body installed in the car and have no more code P17F0. When I put the transmission in it came with a cd for the updates, the valve body did not and it’s cheaper for me to run it to Nissan as opposed to paying for access. So before I cause more problems I’ll tow the car out there and give an update after. I’d does drive front now but seems like it’s in limp mode. May not be surprising due to whatever updates are done to the valve body and not being programmed. I’m not gonna move it more then I did to get it out of the shop till it’s programmed. I did see some stuff I thought was strange in the scanner while looking at live data. Lock up pressure is showing -72.4 engine off or running, primary speed is showing 32 rpm engine off, and slip revolution is showing -30 engine off. Not sure if any of that could be a problem as well. Didn’t really look at it much before valve body replacement so not sure what was there before.


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## VStar650CL (Nov 12, 2020)

If it's dropping into forward then chances are it will be fine, they all act like crap if you try to operate them before loading the IP char parameters.


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## VStar650CL (Nov 12, 2020)

Actually, if I remember right, on the RE0F11 the IP's are stored in the new VB, so you just need to get the TCM to read them. It's a pretty quick procedure, shouldn't cost much because there's no file acquisition or QR-scanning.


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## VStar650CL (Nov 12, 2020)

PS - The 2-speed clutches are going to be "clunky" when you first drive it, even after the IP's are loaded. That's a "learn-in" thing. There's a procedure to speed it up that the dealer can do for you, or you can just drive it 50 miles.


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## TerryG (Jan 13, 2022)

How can I force the tcm to read them? I’m not familiar with the procedure.


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## VStar650CL (Nov 12, 2020)

Needs to be done with a Consult3 or high-end shop scanner with CVT support, but the point is, it's not complicated and the dealer shouldn't charge a ton for it.


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