Hi y'all, I'm still having issues with the 2005 5AT locking up and spitting out u1000 and u1001 CAN codes. I took it to an Infiniti dealership for a second opinion and they told me I needed to replace the transmission. The ATF is dark and there is debris in the pan.

The transmission was previously serviced at 38k and 109k miles. I bought the car at 108k and drove it around for 2 weeks without issue. I noticed immediately after the service at 109k (drain and refill with j-matic) that something was odd with the way the car was driving - I made a mental note but didn't say anything. About a week after the service at 109k, I started to get the u1000 and u1001 codes and limp mode.

From what I've read here, it sounds like perhaps service at 109k miles knocked off a bunch of the debris and is making the transmission worse. I COULD do another drain and refill ...

What do you guys think? Is the transmission toast? Or should I just do a few more drain and refills? Will the transmission relearn how to work without the metal shavings as friction?

Thanks!

 

Did YOU or the DEALERSHIP do the replacement? If the dealership did.... Their flush led to a bad transmission. Causation WOOT!

 

An independent shop did the drain and refill at 109k. They used Nissan J-Matic. Do you think they junked my transmission?

 

Do you know for a fact the independent shop just did a drain & fill using Nissan fluid or did they put it on one of those machines? Before you "Throw in the towel" on this trans I'd do one more drain & fill using the correct fluid, there's no way your trans fluid s/b burnt if it was changed recently using the correct fluid!
Gary

 

Specifically, I remember the guys saying that they needed to get "special Nissan fluid" for the drain and fill. On my invoice, it says Nissan J-Matic. I was planning on doing another drain and fill at the dealership this time. Supposedly, prior to the drain and fill at 109k, the guys at the independent shop noticed that the tranny fluid was "dark and needed to be serviced". I paid approx $100 for a "service" - I don't think it was a flush.

I would much much much prefer to keep this transmission. I'm hoping maybe a couple of drain and fills to get the stuff out and perhaps a reset (can you reset a TCM?) will solve this.

 

Can't think. You need to know. Most times a trans flush causes more bad than good.

 

Your transmission has bunch of clutch disks in it. They wear out and contaminate oil with its wear dust. Oil becomes sticky and kinda provides traction to worn clutch plates. When new fluid is introduced to the system often times transmission starts to slip. For situations like that there are ATF fluid additives that make oil more sticky (just like the old fluid was with all that clutch plate debris). Often times those additives are a short term solution.
Having said that I would be very surprised that it is the case with your transmission. I have 178k on my transmission and last time I did drain and fill was at 100k. And my transmission works fine. So I do not believe your clutch plates could be so worn that they are slipping on new oil.

Chances are your transmission was hocked up to a flush machine when the shop did your service and damaged your transmission.
If I were you. I'd pull the pan and examine oil for my self. If there are metal shavings and other debris found in the oil. I'd start a fight with a shop. If oil is clean (dirty, but no shavings or debris) than you might just have worn clutch plates and might wanna try the additive to see if it solves the problem. If nothing works REBUILD the transmission. No need to buy a new one. Sometimes though a junk yard transmission will cost you less than to rebuild one.

 

Hmm ... this is the receipt that I received from the independent dealer:

4 units 10108-042E type J auto transmission fluid
Drained and refilled transmission

I think, short of accusing them of lying verbally and on the invoice, that we have our answer regarding the flush vs. drain/refill.

 

I've been hypothesizing that the TCM is to blame on this car. I know that if I were to replace it, I'd have to replace the valve body. And if I were to replace the valve body, then I might as well replace the transmission.

Is it likely that the drain/refill at 109k diluted the stickiness so now the transmission is slipping and the TCM is freaking out, thereby sending u1000 and u1001 communication errors to the ECU?

Is there any way to, say, reset the TCM to relearn where the clutches are? << and if you could reset it, would it be worth doing another drain and refill to clean out the junk or is the junk ultimately beneficial?

 

To pull the pan out, I'd have to lift the car, right? I've seen pictures, it's at the bottom of the car and bolted on by several bolts.

 

yes.
The pan is what's covering the bottom of the transmission. You will have to drain the fluid first (there is a drain bolt on the pan).

I mean no offence, but if you have to ask what is the pan on the transmission. You probably should not touch it.

 

None taken.

However, there has been a new development:

On my way home from work today, I'm going about 60mph on the freeway, not driving her hard. Out of nowhere, the car downshifts and the CEL turns on, then goes away after one second and re-upshifts. It felt like the car ALMOST went into limp mode 4th gear but had other thoughts. The rest of the ride (5 mins) is clunky, transmission-wise. Coming off the freeway, the car had hesitation/chunky shifting down to 1st gear.

I pull her into the garage and back up into my spot. Upon realizing that I parked like an jerk, I got back in to recorrect. On first try, she cranked rapidly without starting (for about 5 seconds). On my second try, she starts after a 5 second crank (there is no CEL). I adjust my parking job, then turn her off. I decide to try to crank her again to test, and she refuses to start after 5 seconds.

I've looked over the service history report of this car. Most of the work from 0-108k miles was done at an Infiniti dealership in PA (I'm in CO). I don't see anything anywhere about the spark plugs. IIRC, this car has not had spark plugs replaced. I wonder if that would affect the u1000/u1001 codes + driving hesitation...

 

Pulled code P0335 Crankshaft Position Sensor out of the computer on this one. I wonder if this explains the driving hesitation + u1000/u1001 codes?