Nissan Altima Hybrid Transmission Questions

fgrossm1

My 07 Altima seems to have some type of power issue. If i start from 0mph and press the peddle down a thirdof the way (50kw) and keep it in the same place when the car gets to about 45mph the car kicks the power meter all the way to 0 forcing me to press the peddle down again to get it to stay at 45. It almost feels like it could be the cvt doing something. Feels like shifting from 2nd into 5th - very annoying. Took it to the dealer who told me this is how they work - i dont think so as it wasnt doing it when it was warmer.

PF_Flyer

Since we don't have one at the moment I'll rename this discussion to make it our offical home to discuss Altima hybrid transmission issues.

langjie

well it's supposed to do that if you let up on the gas...but if you are keeping the pedal at the same place, it shouldn't do this

themouse

Does anyone know whether the transmission on the NAH is a similiar CVT used in the other Altimas, or if it's a planetary CVT like used in the prius? I'm a big fan of Nissan's CVT and the software that accompanies it.

themouse

Anyone know the answer to the above question? Thanks

langjie

I've read an article that said it was Toyota's, but I've also read that it's their own take on the CVT. I would say go to the dealership and drive both and see if you can tell a big difference

themouse

I've driven a first gen prius and the NAH. But that's a big difference... maybe I'll test drive the Camry Hybrid.... I'm just concerned about all the moving parts in Toyota's planetary CVT

langjie

I think you can call Nissan to ask, that's probably your best bet

fgrossm1

Update to original problem!!!

Problem still exists and is repeatable. From a standstill press the accelerator down till power level is an inch over the 50kw line. When car gets to 50mph slowly let off on the accelerator as the power drops off it will hang at the 50kw power level and stay there even as you let power off then suddenly power will drop from 50kw to zero which will force you to press down on pedal again to get enough power to maintain constant speed. I would like to know if anyone else has this issue. The car does not stop running or sputter or misfire but feels like it is kicking the gas engine out and substituting the electric engine in its place. The effect is like driving a standard transmission car under heavy acceleration in third gear and taking your foot quickly off the gas the [power drops and nose slighly drops.

The local service manager rode with me as i showed him the problem and he agreed that the power drops off abruptly and he was able to replicate the problem with him at the wheel. He called his hybrid tech who looked at it and stated it was normal function of the car. I called corporate twice on this. Once a year ago when i originally noticed it and also last week. They even let me take a used 2007 altima hybrid to see if it also does it and it does it too but power does not drop as suddenly as mine. Corporate states car is doing what it is programmed to do. I told them it was a safety issue as I do not expect ANY car i buy to loose power while i am driving it.

I beleive the programming on the car is the issue. When it is put in that small power/speed regime it is programmed to drop power to battery or shift cvt to full overdrive or such. I also never seem to get the milage stated30-31 is my usual mpg with winter readings in the 27-28 range.

Nissan has a safety issue regarding this and i am going to contact the NY state attorny general and transportation safety admin. If they do not do something I will seek legal representation for a possible class action suit.

I really love the look and style of the car and would love to keep it but the constant power drop is so annoying i cant stand it anymore.

Anyone have any ideas? Anyone know if it is possible to buy a car data logger that will tell me exactly what the car is doing as I drive it. I am considering buying some type of data logger and hook it to a laptop so I can figuire out exactly what the car is doing when the power drops but im not a car guy so dont know what the sensors report and what equipment i would need to hook up.

Frank

langjie

I wonder if they can give you an ECM update

bostoncigar

The parking gear failed on our 2008 Nissan Altima Hybrid today after the car was turned off and the car rolled backwards into another car damaging both vehicles.

Has anyone else have a parking gear failure? (without the parking brake engaged)

langjie

how steep was the hill? I haven't had that problem

nemo7

I see this question is pretty old and I'm sure you have your answer by now, but I just bought a NAH Wednesday (with no intention of buying a hybrid, but it just worked out that way during this crazy CFC program). I had no idea what this car was and how it worked. I spent a lot of time online this weekend trying to find out about the transmission, with limited success. It is pretty clear however that the system is equivalent to the Camry, of which a key component is the power split device planetary gear set. I have not been able to find out if the power split device is purchased from Toyota, or if Nissan built their equivalent, but it is clearly a very different animal than Nissan's "standard" CVT. The power split planetary device appears to approximate a CVT. Three shafts enter the power split planetary: Engine, Motor, and Generator. The electric motor is locked to the differential with it's speed tied to vehicle speed. The Generator and Engine are the other planetary inputs and have to equal the output shaft (Electric motor shaft) speed. The car's power controller adjusts the generator speed to get the engine speed where it needs to be. Very clever and "simple" concept! I'd not be worried about it's reliability or it would have bitten Toyota long before now (famous last words)

So when I bought the car I had no idea why the KW meter read what it did while driving. Now I think it makes sense, I guess at highway speed in order to get the engine RPM down, the car controls the generator to speed up, generating more power, which it dumps into the electric motor.

In my searching I found some good links on the Toyota planetary systems if anyone is ineterested. I suspect Nissan has nothing out there.

cephraim

I'd be interested!

Thanks!
Eph

nemo7

Eph, sorry I was off for a while, hope you find these informative.

http://auto.howstuffworks.com/hybrid-car7.htm

http://www.toyotapartsandservice.com/pub/pdf/TechCenterLibrary/ToyotaStarService- News/2007/2007_TSSN_Fall.pdf

http://www.osti.gov/bridge/purl.cover.jsp;jsessionid=F5CBE51F1B2FBDF8F160E7C999C- 2C97A?purl=/921781-VVowU8/

cephraim

Wow! Lots of info to read! thanks!

cheung_wilson

Has anyone checked CVT fluid before? I checked the manual, it says take the car to the dealer to check or to replace CVT fluid, duh!!!

krouda1

I have a recurring problem that at highway speed for 30-50 miles when it is hot out (takes longer if it is cold) my 2008 NAH loses power and the CVT gets so hot that it will start to smoke.

I have no problem around town and when I brought it into the dealer, they said it had not thrown any codes. They drove it and couldn't replicate the problem, but weren't willing to drive it the 30-50 miles it usually takes for the problem to happen.

But I've had this happen so often that I am QUITE sure it is a real problem.

If the temperature outside is cool, I can sometimes get it to go a couple hundred miles by babying it going up hills and not exceeding about 65 mph. But if I go 70-75 mph, it will happen no matter what.

Any ideas?

firas1980

Hi
I imported my Altima hybrid 2011 from the USA , unfortunately the nissan dealer in our country does not import hybrids or their spare parts.

As I bought this car as used, I would have liked to change the eCVT transmission fluid as it has 44000 miles on it, I have read the maintenance book, and it says that the fluid is very specific for this car and have to use nissan genuine Matic W, which the dealer in our area does not have.

Some people have told me you can use Toyota ATF WS, which is specific for Toyota Camry hybrid (as nissan hybrid system is licensed from Toyota ).

Can some one help me with this problem, I am afraid if I do that I might damage the transmission ..

Thanks

krouda1

So, the problem persists (yes, after all this time), but now I know a little more about it. I took a Nissan tech out for a long ride on the highway and when it did its thing he confirmed that the eCVT is "slipping" because it is getting too hot. His preliminary research uncovered a service note about the eCVT, but I think to the 2.5 and not the hybrid. The note says that at speeds over 65mph for a prolonged time (less time if you're going uphill) the transmission will do this. They suggest an aftermarket device that attaches to the CVT and keeps it cool.

No word yet whether the note applies to the hybrid, whether it would be covered by the warranty, etc.

So my question is whether any of you know whether this has been a common issue with the Nissan 2008 eCVT, with the hybrids, etc.