How do you get to the ECU? I can't find anything explaining exactly how to get to it. Wire diagram says its behind passenger dash somewhere. Nissan site says it can get water runoff from windshield, and makes it look like its behind panel under hood. Where the hell is it?

 

I think I found it. Its behind the glovebox above to heater core. You have to remove the right side of the lower storage box to remove the radio bezel to get to 2 of screws for the glovebox assembly and then 4 more in the glovebox opening. The glovebox itself fold completely forward by pushing in on its stopper pegs.

The ECU has a white plastic plug across the front w/ a single 10mm bolt holding it in place. That bolt is retained, so back it out & the plug comes off. To get it out of there, you have to remove that dash support in front of it. A bolt & 2 nuts hold it, but ity has to be convinced to sqeeze out of there. Unfortunately there's another connector mounted to the top. I gave up at this point. In the end, having the battery disconnected, and unplugging the ECU for a minute seem the have cleared the codes for now. I was looking for a diagnostic mode selector on the side of the ECU that is a manual reset for the codes. But that was according to the Quest manual. But even the location is different between the two. So the ECU maybe completely different.