I was really trying to avoid a dealership, but if the trans shop can't and i have to go for this, can dealerships simply do this for me only or they will they hit me with "well we have to do this this and this before we do that" just curious on what to expect
Slow acceleration
08 Altima 2.5s, recently installed used engine and trans...TCM from original car but TCM reprogrammed and car ran fine. ECM from original car. New valve cover, new cat and 02 sensors.
Driven a few hundred miles now and no codes yet BUT after it gets to operating temp, acceleration from dead stop is super slow, almost non existent and then all of a sudden it gets up and goes. If I put it in park and try to Rev engine, it does so suuuper slowly. If I turn off the car and turn right back on acceleration is fine for a while and then repeats. Brake lights not on when it happens so I don't think it's the brake sensor that other have experienced.
Throttle body? Intake system? Other Ideas?
Anything is much appreciated!
Driven a few hundred miles now and no codes yet BUT after it gets to operating temp, acceleration from dead stop is super slow, almost non existent and then all of a sudden it gets up and goes. If I put it in park and try to Rev engine, it does so suuuper slowly. If I turn off the car and turn right back on acceleration is fine for a while and then repeats. Brake lights not on when it happens so I don't think it's the brake sensor that other have experienced.
Throttle body? Intake system? Other Ideas?
Anything is much appreciated!
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That depends entirely on the dealership. If they're honest then they won't have any problem doing the work you specify, although they may have a 1 hour minimum charge. If they aren't then they'll feed you a bunch of stuff about diagnosis and charge you over the top of that. Much of that depends on whether you sound like you know what you're talking about. Ask to speak to the Shop Foreman or a Lead Tech instead of a Service Advisor, explain that the tranny has been replaced with a used unit and you just need the IP Chars loaded. Any decent tech will know what you're talking about and know it's an easy operation, so you'll inherently limit any BS from the advisors. Keep in mind that SA's and even Service Managers are rarely technicians. They simply won't know very much, so talk to the horse's mouth and not the other end.
Do I also need to request all ecu/learned value data be wiped or will them loading ip Chars automatically do that?That depends entirely on the dealership. If they're honest then they won't have any problem doing the work you specify, although they may have a 1 hour minimum charge. If they aren't then they'll feed you a bunch of stuff about diagnosis and charge you over the top of that. Much of that depends on whether you sound like you know what you're talking about. Ask to speak to the Shop Foreman or a Lead Tech instead of a Service Advisor, explain that the tranny has been replaced with a used unit and you just need the IP Chars loaded. Any decent tech will know what you're talking about and know it's an easy operation, so you'll inherently limit any BS from the advisors. Keep in mind that SA's and even Service Managers are rarely technicians. They simply won't know very much, so talk to the horse's mouth and not the other end.
The old IP Chars get wiped in the process of reading the new ones. There are no learned characteristics on an Altie CVT, I wish there were. If they would simply make the stupid TCM's "learn" to tighten the belt a hair when judder is detected, we'd all be better off. The only learned characteristics on any of them are for the 2-speed Sentra/Versa CVT's, and it only applies to the planetary high-low clutch. None of them have any learned traits for the belt. The ECM's do have learned memory, but that doesn't apply here.
If you want the memory for judder DTC's and CVT-A/CVT-B cleared out, that requires reprogramming the TCM firmware. I think yours is too old to have judder detection, but basically all those things disappear when you update the operating program, whether that's an actual update or simply a rewrite of what's already there. The repro isn't a big deal if you want it done, usually 20~30 minutes' work (including setting up the hideously slow C3+).
If you want the memory for judder DTC's and CVT-A/CVT-B cleared out, that requires reprogramming the TCM firmware. I think yours is too old to have judder detection, but basically all those things disappear when you update the operating program, whether that's an actual update or simply a rewrite of what's already there. The repro isn't a big deal if you want it done, usually 20~30 minutes' work (including setting up the hideously slow C3+).
PS - If you got CVTz50, I recall something in another thread about there being a trick you could pull to get it to wipe and read the IP's. I use the C3+ and I can't recall the details, but maybe Rogo can help us out and find it. The tech folks at CVTz50 are very helpful and knowledgable about their product, so you could also check directly with them.
So I just talked a lead tech at nissan, he said all they would do is hook it up to consult3 and load the characteristics of the used tranny into my existing tcm. Is that right?PS - If you got CVTz50, I recall something in another thread about there being a trick you could pull to get it to wipe and read the IP's. I use the C3+ and I can't recall the details, but maybe Rogo can help us out and find it. The tech folks at CVTz50 are very helpful and knowledgable about their product, so you could also check directly with them.
He said nothing would need to be done on the computer for the engine side...also right?
So I talked to the guy who did the reprogram and he said they have access to nissan software through consult. Said for my car since tranny didn't come with paperwork, qr code, they had to download software directly from nissan to input to my tcm so it sounds like that was done properly.Correct.
He mentioned that it could be the solenoid pressure? Said that would have to be tested while hooked up to a scanner while the problem is happening and the fix could be a new valve body for tranny.
When they run with low line pressure you almost always get codes, usually a P0841 but sometimes P074x's or a P0840. Almost all of those codes are "deduced" by the TCM from comparing the actual turbine, input shaft, and output shaft values against the theoretical values. So if the tranny can't change ratios properly and that's what's causing your problem, there should be some indication.
Trans shop said there were active codes they found... p0746 and P0868.When they run with low line pressure you almost always get codes, usually a P0841 but sometimes P074x's or a P0840. Almost all of those codes are "deduced" by the TCM from comparing the actual turbine, input shaft, and output shaft values against the theoretical values. So if the tranny can't change ratios properly and that's what's causing your problem, there should be some indication.
They were either going to shop around another trans for me or try replacing cartridge filter and internal filter...i dont think those were ever replaced...any chance that would help at all? I don't know ow how much more $ I want to throw at this car...They said they found some debris in pan, didn't sound too bad though.
Am I out of luck here? Just feels like the car drives too good until the slow throttle thing...
The P0746 sounds like low pressure, but if the codes were both "past" I'd try getting fresh fluid in it, clean or replace the screen and replace the cartridge.
I think they are saying present now, but that fluid only has maybe 500 miles on it, if that, and is clear as day. It nissan fluid.The P0746 sounds like low pressure, but if the codes were both "past" I'd try getting fresh fluid in it, clean or replace the screen and replace the cartridge.
I was going to let replace the cartridge and clean the screen I guess. Think that makes a difference as it relates to my issue and the codes I suppose?
P0868 also refers to pressure?
Yes, P0868 is secondary pressure. It's usually more characteristic of a bad Valve Body than a bad pump. If the fluid is fresh but the codes are "current", the trans has probably had it. 
Is that how it's labeled in the scanner? Past or current? I want to know how to ask so they know what I mean..Yes, P0868 is secondary pressure. It's usually more characteristic of a bad Valve Body than a bad pump. If the fluid is fresh but the codes are "current", the trans has probably had it.
Past means it previously had those codes?
Current means it shows active codes now?
Different scanners work differently where that's concerned, so you really need to consult the manual and/or the manufacturer. The Nissan Consults all use, "current" and "past".
Gotcha.Different scanners work differently where that's concerned, so you really need to consult the manual and/or the manufacturer. The Nissan Consults all use, "current" and "past".
So if I'm dealing with "current" codes, by replacing cartridge and cleaning filter, will that help at all with the issue you think?
Hard to say if that would fix the issue I know...trans shop said they couldn't guarantee doing that would fix the issue
Probably not. If they're "past" then it might be that the pressure is falling off whenever the tranny heats up, so cleaning things out may help. If they're current it most likely means a failing front pump, which pretty much means the tranny is toast.So if I'm dealing with "current" codes, by replacing cartridge and cleaning filter, will that help at all with the issue you think?
Does the front pump fail intermittently? Only when it heats up?Probably not. If they're "past" then it might be that the pressure is falling off whenever the tranny heats up, so cleaning things out may help. If they're current it most likely means a failing front pump, which pretty much means the tranny is toast.
Shop is quoting me 3k parts and labor on a used trans with 110k miles. 90 day warranty 🙁
No, but when the fluid thins out from heat, a dying pump can have trouble with pushing it because of internal leakage. That results in low pressure when warm.
Given I have these codes even after new filters, would that cause my rpms not to rev up? Just thinking when the no throttle happens, my rpms do nothing for a few moments and then all of a sudden rise and car goes...No, but when the fluid thins out from heat, a dying pump can have trouble with pushing it because of internal leakage. That results in low pressure when warm.
I had to drive it approx 80 miles yesterday for the slow throttle to happen. Just trying to make sure I cover all bases b4 I give up on this car..
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