Sampling rate is low so if you can increase it would help. Also log the Primary and Secondary pulley speeds if possible along with Target Gear ratio.
Looking at 18:50.49 I see a couple of odd things. The (4) Pressures (Line, Primary, Sec Targ, Sec) are all maxxed out. Secondly, in Park it's showing the slip revs at 11 to 25. Normally the torque converter is unlocked and it'll read 127, it's not. Thirdly in Park it's reporting actual torque of 9-12 N-m. It should read zero. That is some really odd behavior for a CVT in PARK and idling. Normal pressures should be 1.0 to 2.0 Mpa across the board and converter slip revs at 127, torque would be 0. Also, and this doesn't make sense but right when you hit about 69*C the CVT starts acting bizarre. Before that everything looks fairly normal. Aftwards the Park and Drive pressures are very high and almost identical which makes no sense.
Secondly, most times the TCM can achieve Secondary Target pressure, some times it can't. This isn't normal. It's telling me either: 1) Secondary Solenoid intermittent issue 2) Leakage in Secondary hydraulics circuit. Why the TCM wants to hit a high Pressure might be because when it detects any slippage it wants to ramp the pressure dramatically as a protection method. This is happening but it should only be temporary and go back to normal. The air-leak check needs to be conducted would be the first step.
So basically it seems like the clutches & torque converter are not slipping. What would show the belt slippage clearly is the Gear Ratio vs. Target Gear Ratio. The sampling rate isn't high enough to see that because you keep getting on/off the throttle. This value dips and increases and it looks like slip but it's hard to tell. The various Pulley speeds from the speed sensors need to all match the respective gear/speed ratios and the differences are the slippage, that's important to see. So for instance Engine RPM needs to match the Torque converter rpm (Input speed) when locked-up, and the Torque converter RPM (Input speed) needs to match the Primary RPM (Primary Speed). Any differences between them is slippage. The Gear ratio difference means Primary Rpms and Secondary Rpms are slipping between them though they will be different of course due to Gear/pulley ratio but that can be calculated to see if they are off Target.
Some areas I can see the ratio change from 2.65 to 2.42 and back to 2.65. That looks like slippage but the throttle load also drops and it's not logged at a fast enough rate to confirm it along with the Target Ratio to compare exactly. If this was the slippage then it's huge because the TCM can hit that target within .01 ratio and anything higher you would definitely feel the rpm slippage and see it. The pressure increase at the end of the run is some kind of intermittent issue. The wire that was damaged was connected to the Secondary pressure sensor. Being shorted or partially shorted I'd be concerned there is some damage leading back to the TCM but it's hard to know for sure.
If you air-check the CVT you can rule out the transmission itself. The valvebody I personally think it's junk and would recommend a new unit or another good refurb from a reputable source that has bench tested the solenoids and sensors and repaired/refurbed the internals correctly and vacuum checked. All of the harnessing and grounds have to be checked and repaired before anything else. Possibly the TCM is having issues but that would be last on the list, they can be purchased used and reflashed by the Dealer if it's the problem. That is essentially the entire CVT control system minus the speed sensors.
Basically that's how I see it. You have control problems, the wiring was damaged and the valvebody is highly suspect which controls nearly everything under TCM command. The used pulley case I don't believe is the issue but air-check would confirm it.
Just ordered another reman valve body from an trans shop on eBay with 99.5% feedback and thousands of reviews. They said theirs is not salvage and that they reman them and dyno test them guaranteed 100% functioning. Hopefully I get a good one this time around. In the meantime I‘ll pull the one on there now and air test as well as continuity test the rest of the trans harness to rule that out. I’ll go ahead and re-inspect the pulley and belt with my inspection camera to see if it’s all still usable.
That all makes sense. Shouldn't have problems if they electrically test and dyno with the valve-body then it's legit. You're probably good on the belt & pulley but using the camera to check it then you can make a judgement call. Slippage at light load is way better than a full load slip which is much more abusive/destructive. That doesn't sound like the case here especially from your log runs the slippage occurred at light/moderate loads. So I wouldn't stress over it but verify and confirm is a good call anyway.
The (3) speed sensors if you can remove and clean-off and reinstall would help too. A failed belt will throw a lot of metal debri and it'll usually stick to the speed sensors. They sometimes come with shim washers to set the hall effect gap distance, check for that under the sensor below the screw mounting surface and keep them with each sensor. This'll prevent any speed sensor codes in the future and it's pretty easy to do even on the vehicle while your correcting all the other issues.
Below is the wiring diagram for the valvebody. Might take awhile to do the continuity and short circuit checks but it'll be worthwhile. You can see how the Secondary and Primary pressure sensors share common Power and Grounds, so the cut wires would have affected both sensors.
Curious to see how your rebuild works out but it sounds like you have a solid game plan and having the right parts to make it happen goes a long way.
Well I just got through testing some things. I pulled the “salvage” valve body off and tested the harness from the TCM to the round trans connector where it plugs in. All wires tested good for continuity (solid beep in diode mode). Tested the short harness from the inside of the trans to the valve body and all wires tested fine as well with the exception of one of the smaller black wires showing resistance but it appears to be the wire that goes to the temp sensor that’s built-in so I believe it should show some resistance.
On to the fun 90psi air tests. I tried various ways to test the secondary Pulley but that port is sideways and buried in a channel. That channel has another side shoot channel near the top and I couldn’t find a combination of rubber tip or metal wrapped with electrical tape to give me a good enough seal. I moved on to the rest of the ones that I could test. The reverse clutch has a tight seal with no air leaks. The primary pulley compresses but I can hear and air leak. I can also hear a very light leak in the forward clutch. I tried testing the TCC Apply and it build and then blows air and fluid out of the TCC Release port. The TCC release blows air out of the TCC Apply (not sure if these are normal).
I am attaching a couple links with videos of the primary pulley and forward clutch air tests.
I know there is a lot of hate towards used CVTs but I’ve been looking around and found a couple now that are under 50k miles and less than $1300. Nissan wants $2600 plus tax for a new one. Whether new or used, would it have to be trailered to Nissan after install to have them program the TCM for the trans or would the current TCM work fine with a used trans of the same model?
I’m back and forth on whether I want to pull this one and attempt to rebuild it or just buy one that I know works and has a year warranty. I’m doing my work from my families garage at the moment because we are renting and don’t have a garage. I’m trying to avoid having garage space used for weeks while I attempt to fix this one.
Buy the brand new one...A used CVT at 50k is just asking for trouble. Troubleshooting and trying to rebuild the one you have will end up costing you more headaches than its worth. I know some people on here will tell you to rebuild it as "it will save you X amount of money". But those people have a lot of spare time on their hands...A LOT.
If you enjoy doing it as a side project and dont mind throwing contless hours/money, by all means go for it. But if you need this car up and running and not having to worry about doing this all over again in a few thousand miles, buy the brand new CVT.
To be honest, given what I’ve seen in this CVT trans so far, I’m considering getting it running right and trading it for something with a standard automatic. I feel like even a new one is still a ticking time bomb after my experience and everything I’ve read about them. Also, I’m assuming with a new one I’d also need to buy a torque converter for it in order to have any kind of warranty on it or could I reuse my existing one? Nissan wants another $1k+ for a torque converter.
As far as time, I’m not really in a time crunch necessarily, I did find a storage unit I could pull the car into and work on it over time if I needed to. My daughter won’t be driving for at least another 3 months. My biggest thing about pulling it to rebuild is if I’m going to have to spend another $1k in buying special tools to disassemble and reassemble.
Yeah. Short recommendation is a reman would be my recommendation. I think they are about $1800 once the core is returned. Nissan run specials every so often and my dealership had reman for $1580 but the Gen2 were slightly higher. The primary and secondary should not leak, neither should the forward clutch. This tells me they reassembled the pulley set with the wrong piston ring or clipped the OEM ring during the install, or there is leakage in the various gap rings on the case or input shaft. You caught it in the air check so that is a great find. Any of these would make slippage very likely, tough to say if it was the vavlvebody or not. The high pulley pressure is exactly what the ECM would normally do if the belt was worn or slipping, mine did this too and it was a mechanical issue and not the valvebody but swapping it helped but didn’t cure my issues at the time.
Used low mileage wouldn’t be a bad idea for anything 50k mile or lower I’d say it’s worth the risk and they have the warranty if it doesn’t work out of the box.
I think you have the knowledge to fix it but the parts you received are the problem. The full teardown is required and the quality of each replacement part makes a difference but these are rebuilt successfully. The few that have done it I’ve spoken with were transmission professionals, CHIDog did it but he does this for a living, we shared some notes. He’s on the Altima forums and a couple of other guys there have done it too. Needs to be someone who is used to transmission builds bumany shadetree mechanics have rebuilt a CVT no issue. Dealer can reflash the TCM, I did but didn’t even need it but swapping the ROM pack over from the original valvebody is how to avoid that issue of codes after a rebuild or valvebody replacement.
Economically the used or reman is the most practical approach.
Just looked at the primary air check video. This is exactly what happened on my build. Faulty aftermarket piston rings cause the same leak. Switched back to factory as WIT transmission recommends, air tight.
Reman torque converter is $200 or so from CVC converter, they are a manufacturer of reman converters. WIT would have them. No way I’d buy a new converter for what they charge. I paid $147 without the core refund.
None of this would dissuade me from owning a CVT at all. It requires good maintenance and a driving style adjustment but I plan on driving mine hard. If you fix it say with a reman unit you could flip it easily. My Nissan dealer is always complaining that nobody wants to give up their Juke on a trade so it’s worth the investment to get it squared away. The Nissan factory reman is potentially the highest quality transmission you could get short of a new one which is not offered anymore.
Thanks for the info. Also, I couldn’t find a Rom around the valve body. I’ve seen this referenced a few times on the earlier CVTs. I have wire harness and connectors from the TCM to the solenoids and valves on the valve body. I couldn’t find anything that resembled a rom/chip/box anywhere. I’m wondering if there’s anything after the factory TCM that would actually need to be reprogrammed or swapped electrically if swapping the CVT or if I could literally just swap, plug in, and go.
I’d read The ATSG manual I attached. There is also the Nissan TSB for your JF016E that explains the exact workflow for a complete pulley case swap and the self learn and reflash steps. I can attach it here. I’d still have them reprogram the TCM. They’ll have the latest firmware with updates. The ROM on the earlier units tracks the solenoids performance. Not sure about the Gen2 but possibly this is now carried internally on the TCM. In that case it would be plug and play minus the reflash.
yeah I’m guessing the ROM is now part of the TCM on the gen 2. I’ve seen the Nissan TSBs for the pulley case swap which is what gave me the idea to try it. I guess that would have worked of the pulleys and belts had worn down from lack of maintenance with spirited driving rather than other failed internal parts.
Most likely it's embedded, yes. Page 78 thru 89 covers the TCM reprogramming. This'll also cover the DTC reset, FWD clutch point learning, select learning (drive/reverse learning), erase CVT fluid degradation level data. For an existing TCM and new/reman transmission probably going to require a dealer visit just as a precaution. They can also re-flash the TCM to the latest firmware and I think there was a fix for this generation CVT for the clutch shudder issues which is why the TSB was created. This would be the main reason to update the TCM firmware if it wasn't already done so.
Well I may have lucked out as I was able to order a Nissan Reman for $1700 (after core) with dealer and winter sale discounts and it will be in at the dealer tomorrow. So it looks like I’ll start pulling it again today.
Good find. If it's local that's the way to go. If you can get a refund/return on that refurb valvebody you can then get some of your money back or sell it back on e-bay as well. Then reinstall the original valvebody back into the core and just return that all together. Might also be worth doing the same with the reman pulley case set since everything is already out shouldn't be too much work.
Yeah, I’m buying it from Bill Kay Nissan in Chicago which is about 2.5 hours from me. It’s right next to where I picked up the pulley set. Already called that guy and he said I can bring them back and he’d work with me on giving some money back for whatever isn’t damaged. Returned the valve body today and throwing the old one back on tomorrow. Aside from another set of NS-3 fluids I should come out ok on it. It sounds like my TCM is ok and assuming I plug it all in and fill it with fluid I should be able to drive it up to my local Nissan dealership and have any TCM updates installed. I know I can reset DTCs and the CVT fluid degradation level through the app but I don’t believe I can do the others. You think I’d need to trailer it to Nissan after the install to have them do the different learnings tasks before I can safely drive it?
That price is good. I buy all my stuff from Bill Kay Nissan and no one can beat their prices. All depends if it starts throwing codes or starts shuddering then I'd just park it and tow it in but see how it goes. If not then I'd definitely still drive it in & schedule the TCM relearn & reflash procedure whatever it costs. I think your making the right decision and the OEM reman is the better option to get it done quick as possible.