Hey guys got a 05 G35x 5AT about 138k miles on it. So lately like 10% of the time when I start my car up and try to switch it to triptronic mode, it�ll still be in automatic. The only way to fix it is to turn off the car n start it back up. Have any of you guys had this issue? Things to note im due for an oil change would that have to do with anything? I also havent touched the tranny fluid ever since so (shifting feels good)... any feedback would help thanks!

 

My tiptronic used to work like 20% of the time then it stopped working awhile back. Following

 

I've had a couple of glitches with mine over the 9 years I've owned it but they were temporary and went away quickly.

 

Why are you even changing your engine oil then? The motor doesn't start to "feel bad" so why not just check the level and top it off from time to time?

Why are you ignoring the manufacturers recommendation on transmission fluid changes every 30k?

Why are you surprised that you are experiencing a transmission malfunction since you don't maintain it? I recommend getting the fluid changed and cleaning the electrical grounds located at the top middle of the timing chain cover on the engine. Use a wire brush to clean the bolt and the lugs (there are two side-by-side, can't miss them) and reassemble with electrical oxidation inhibitor grease, you can buy a tiny packet from an auto parts house.

The transmission is the second most expensive part on your vehicle, maintain it or it will cost big $$ to fix.

 

I purchased the car when it had 113k on it, the transmission had no issues. Not sure if the previous owners maintained the fluid but I didnt want to take the risk of it slipping.

 

Transmission "slip" is the result of low fluid level causing a drop in hydraulic pressure. Not changing your fluid is a guaranteed way to cause damage to the internals of the transmission, it's mind-blowing how this stigma of "never change your AT fluid" still exists. I should find a link to the short story I wrote about this exact thing so you can read it.

 

Hey I found it, give this a read I'm sure you will enjoy.

https://g35driver.com/forums/g35-sed...ml#post7123536

 

I appreciate it G, ill have Nissan do a drain and fill soon. Hopefully it wont cause any harm

 

Also definitely clean those grounds, the transmission is completely controlled by electronics and a slight bit of electrical resistance can play havoc on the system. Get your battery tested as well to make sure it's still in good condition, this is the time of year when slightly worn components like that tend to fail.

 

There is also some contacts in the shifter that can get dirty. If you look it on YouTube there are some videos that might help. I doubt it's your fluid if there is no shifting issues.

 

I believe this is the fix. The video is on a 07 g35x but it'll be the same principle I believe. I'm gonna try tackling this myself next week.

 

 

I've experienced intermittent issues also. Tiptronic would always work right away but at some point would go back to automatic. I don't use it often but do switch it over to check if it's working all the time. Not sure if it's related but I did do a drain and fill of my tranny fluid recently and haven't found my tiptronic disengaging since then. Maybe tiptronic is heat sensitive and won't engage when the fluid gets too hot? Not exaxtly sure but those are my results. It's as easy as changing your oil

 

Don't quote me on this one because I haven't worked much on this component for the G but typically a "manual" mode for an automatic increases the pressure cutoff which makes shifts feel more "snappy" by making the hydraulic actuators perform the same work but in a shorter time frame and worn fluid has much different characteristics than fresh fluid. The worn out fluid carries a lot of gritty particulates from the wet clutch plates and adds a lot of extra friction to the brake bands and the clutches themselves and there might be a point where the TCM logic knows something is wierd so it just disables the entire Manu-Matic system.

Or it could just be a failed initialization of the system on startup due to corroded contacts in the shifter, never really dug into these auto trannies much.

 

Nissan wants about $215 for a trans drain and fill smh.