Hello I recently took my newly acquired car to the dealer to inspect some problems I've been having and they said that it was the shift control assembly. They were going to charge me over $1000 dollars to fix it so I figured I'd do it myself. I just need help figuring out what piece I need to replace. Some further info is that sometimes when I try to turn on the car it won't start, in this case I put it in neutral and it starts no problem. Other times I don't think when I put it in park the car is actually in park because it does not show on the dash. I own a 2008 automatic G37 coupe. If anyone could help me find what part I need to replace it'd be greatly appreciated!

 

Just search eBay for "G37 Coupe Shifter" and several will pop up ranging from $40 and up (used). Here is a pic of the shifter itself:



Now, if you look closely there is a sensor/module unit on each side of the shifter. These are the shift interlock/DS-MANUAL MODE and the SHIFT POSITION (Park-Neutral-Position) modules. If you are handy and have time, I would remove the two (2) modules/sensors that are attached to the shifter and try cleaning the contacts. There may be some dirt, corrosion, or other issue preventing the sensor contacts from reading shifter position. Here is the shift position sensor module where you can see the sliding contacts:



Best case scenario problem is solved. Worst case your car won't start at all at which point you'd be replacing the shifter anyway...

 

Nice pics! It always helps me to see the guts of electrics. Do you have more of the disassembly and removal of the module?

 

IIRC, two or three screws holds each module to the body of the shifter. Then a few plastic lock tabs removes the cover. For the PNP module (shift position) there are 4-6 screws that separate the slider from the printed board.

You should be able to gain access to the modules without removing the center console. It will be a tight fit but should be doable. I strongly suggest you stuff the area with rags to prevent any of those tiny screws from dropping down into the abyss (ask me how I know).

Just make sure that the sliders are properly lined up when you reinstall the modules- the shift interlock one (the small one) has a tab that fits into the slider which moves when you push the button to change gears.

Helps to take pics as you go. And, hate to state the obvious, but disconnect your battery before doing any work.

 

Finally started the process to replace the control device. Is the control rod accessible through the top after removing the finisher assembly or do I have to remove anything else from the center console to access it?

 

From what I can tell, you will have to disconnect the control rod from the shifter lever from underneath the car. Then, unbolt the shifter from the center tunnel and lift the whole assembly up and out. I do not think there is enough room to access the lower control rod from inside the cabin.