I've put 2008 19" coupe rims on my sedan, now I get the TPMS warning on the dash. Did the 2008 G37 coupe come with TPMS sensors stock?
Are the compatible with 2010 sedan? DO they need to be programmed in?
How can I read the error code for the TPMS?

 

If your stems are black and you can flick them then the sensors aren't on there. They should be a silver color and metal I'm assuming. If all years are the same, there's a big thread about resetting your tpms you might have to swap your sensors from your stock wheels.

 

I'm pretty sure I have the sensors, the stems are silver and solid metal.
I'll search for the thread.

 

There's this https://www.myg37.com/forums/general...s-sensors.html

And this how to reset it https://www.myg37.com/forums/d-i-y-i...-for-free.html

 

I have a 2010 G sedan. And i had fitted mine with 2008 19" coupe wheels with the original TPMS. And i found out that 2010 they changed the TPMS so anything older than 2010 will not work. You can try and do a reset and see.
I even changed the battery in the 2008 TPMS and did the relearn and no luck.

Also you might be in luck with your G if your G is made before 2010 May. After May is when they changed it.