I have a 2008 G37S 5-speed auto with paddle shifters. Shifting into DS mode has only worked sporadically (usually only after start up when engine is cool)for a couple years now, which is unfortunate because I prefer to drive in DS mode using paddle shifters most of the time. The dealer told me I would need to replace the entire gear shift assembly (most likely nothing more than a faulty switch or circuit board) costing $700. That's one problem. The other problem has begun occurring much more recently. This issue involves a failure to rev match and an inability to quickly find the lower gear, sometimes slamming into gear, most noticeably from 2 to 1, when downshifting w the paddle. Upshifts are fine. For troubleshooting purposes, I should have noted whether or not the rev matching feature is working while downshifting w the gear selector and whether or not rev match is working in DS auto mode, when not shifting manually. Unrelated, but I should also mention that a couple years ago I had to replace the radiator which had a faulty seal, allowing coolant to contaminate the transmission fluid causing the transmission to "slip" at times and introducing a strange noise/vibration at about 1750 rpm's. The noise/vibration remains but the slipping has stopped after having trans fluid replaced. Anyway, dealer suggests a TCM/ECM reprogram for an hour worth of labor and/or replacing TCB module or transmission. Has anyone experienced these problems? Any suggestions? I know, I should have bought a manual transmission. Lol. Love the paddle shifters though. Thanks

 

The shifter assembly failure is a thing, I dont believe anyone has found the exact problem people usually just change out the shifter (I did). I also have a hard rev match down shift when I am going from 3 to 2. I have noticed that it only happens if I am already going slow though, If I am in a higher rev to start it isnt as bad

 

Thanks for the reply. So you changed out the shifter assembly? How much was it? Did you install the new one yourself? Was it new or used? I'm curious as to whether or not it is something as simple as a failing micro switch. Have you considered a tcm/Ecm software upgrade for the rev match issue?

 

Yeah I replaced my whole shifter assembly. First time I bought a used one for 80 bucks and it failed pretty soon after. The second time I bought a new one $300, its been perfect since *knock on wood* lol. The rev match issue I haven't really tackled because it isn't really a bad issue to me I just plan a little ahead when I am going from 3-2 to make sure I have some decent revs to start.

 

I actually reset the ecu using the diy I saw on here using the gas pedal. Cleared up the rev match issue. Bought a new gear shift assembly for $300. Haven't had a chance to put on yet.

 

Did you replace the gear shift assembly yourself? It doesn't look difficult. Are you aware of a diy for that?

 

Yeah I did replace it myself, it was not hard at all. I have not seen a DIY for it. If you look at the first 3 photos here http://www.activetechdesigns.com/downloads/AT-G.pdf you can see how to remove the top trim. There are 4 screws that hold the shift assembly down (and a few wire harness's that need to be unhooked). Then there is one bolt under the car on the drivers side that attaches the shift assembly to the transmission. That is it.

 

Thanks for replying. Very helpful. I got the trim off and assembly is exposed. Is the part that attaches to the transmission easily accessible? I don't have access to a lift. It seems like it might be in a bad spot. Idk without jacking it up and it's raining.

 

You do not need a lift, if you can Jack the left front up high enough to get under the car you can access the bolt.

 

Yeah. Sorry. I actually replaced it long before you replied about lift. Tried to post but it didn't save. Anyway, if anyone is having the same problem and is considering having the dealer or a shop install it, DONT!!! The hardest part was figuring out how to remove the trim. Lol. Seriously though. Very easy if you have the right size socket and wrench and a half hour. Shifter feels like butter now. Much thanks to terribleone!