I 2004 maxima im interested in buying can only be driven in tiptronic mode. Does this car need a new transmission?

I would use a scan tool to reset the ECM and computer , then seek advice from an accredited transmission specialist that has experience on your make of vehicle

There are major faults that need to be addressed. The car is in limp mode because the computer is saving the engine or transmission from damage if the car is driven. IF you ignore the problem and do nothing to have the vehicle problems diagnosed and fixed it will stop running altogether.

You get it out of limp mode by fixing the problems with the vehicle - not ignoring them.

Matic K
http://forums.maxima.org/6th-generation-maxima-2004-2008/583365-when-change-transmission-fluid-my-2004-a.html

You might need to change the ECM (computer) and you may be able to put in an oil cooler instead of changing the radiator.
Another way to go would be to contact your local automotive junk yard and purchase a wrecked vehicle that is the same as yours except automatic. The vehicle would need to be damaged in a way that doesn't effect the parts you are interested in. You would then have everything needed to swap over including peddle assembly, steering column or console, linkages, wiring, switches, cross-member, flywheel, driveshaft, correct speedometer gears, cooling lines, radiator and so on.

Ok, I am about to solve the mistery on the transmission problems with these 2004 and 2005 Nissan Maxima.
I had 2 Maxima's 2004, let's call car A with a bad transmission and good motor, and car B with good transmission and bad motor.
1. I swap engines from car B to car A, after that, car A runned good with not a single issue.
2. Car B was with out and engine and a bad transmission,
3. I found a motor and transmission from a wrecked salvage 2005 Nissan Maxima with only 25,000 miles in it,
4. After the installation of the good engine and transmission on car B, I found a broken solenoid,
lets call the good engine and transmission (SET).
5. Remember car A is fixed, but car B had a bad transmission.
6. After removing the bad transmission from car B, the SET had a broken transmission solenoid called (pressure control valve solenoid) cause by the accident, the transmission valve cover had a small dent, right where the solenoid is, that how it got broke,
7. Since I still had the bad transmission from car B, the solenoid from that transmission were good in shape, so I thought I was lucky enough to swap the solenoid from car B to the SET,
after I did that I was good to go very confident that car B was going to run fine, but it did not.
8. Car B with a 25,000 miles SET end it up doing the exact same problem that it had before with the transmission, it is near impossible that the problem is the wear on the valve body since the SET only has 25,000 miles and I only swap the solenoid. 2 of them to be exact.
8. Now I am in the market to buy just the 2 brand new solenoids and cross my fingers, Nissan for some reason, they dont want to sell the solenoids by them self, you need to get the complete valve body assy. and shops are happy with that idea cause it is more money on the pocket for dealers and shops, so I hope is the solenoids, they are really easy to replace, just by removing the valve body cover and remove 2 bolts, 1 for each solenoid and that's it. I called one guy who owens a shop and I ask him if he sells the solenoids remanufactured and he started yelling cause he is thinking that we are stupids since he had many people asking about these solenoids and he is saying that the problem is the valve body it self, he make me mad because I only asked him for the solenoids not to try to make me buy the new valve body assy. I will follow up after I find the solenoids and replace these on my Maxima just to confirm, any questions e mail me back at [email protected] thanks

VW fill the gearboxes "for life" which means it must be changed at "regular intervals as specified in the dervice manual"you could leave it as long as you want,but could cause problems later.(especially if the car is driven HARD.)the (VW)oil for the tiptronic gearbox IS expensive.

The tiptronic is not the DSG - two separate transmissions. You don't need to service the tiptronic every 40k like you do the DSG.
VW considers the fluid in a Tiptronic tranny as "lifetime" fluid - it doesn't need to be changed.

im having this problem with my '03 jetta. No response when i shift right. and i get this buzzing noise when i shift into reverse.

It is not recommended by the manufacture to change it,They say it is lifetime fluid.

The Gearbox Control Unit Is Defective Inside The Rear Of The Gearbox