I had high idle after cleaning the Throttle Body on my G35. The TB was very dirty, I've moved the plate with my fingers, forcing it open and after the cleaning i ended up with the common high idle problem. I did the relearn numerous times, it would set it to 725, and forget it as soon as the engine was turned off. The ECM only remembers if it is in the normal range (650± 50). What I did to set it to normal range was: did the relearn and during the final step (waiting 20 seconds after starting the engine) I pulled up on the switches to all 4 windows at the same time, hence lowering the rpm, which now falling into the normal range is remembered even after turning the engine off. I have AT.

 

wtf? lol for reals?

 

Yes, it's been a few days now, idle is okay. I also used to get the "P0507 - Idle Air Control System RPM Higher Than Expected" trouble code, but not anymore.