I need to replace this. can someone tell me where it is and some pictures would be helpful. is this just a simple replace?

http://www.nicoclub.com/FSM/quest/2005_Quest/ec.pdf

page EC-314 to EC-321

EC-319 is the location under the vehicle

and http://www.nicoclub.com/FSM/quest/2005_Quest/em.pdf

see page EM-31 to see #17 & the small metal heat shield #18 if you have the 5-speed trans

http://www.obd-codes.com/p0335



ps: did you rule out that your ECM isn't corroded? it's located in a weird location & I've seen them prone to corrosion from another member

Thank u. Do u have the locations of the ECM? I even don't know how it looks

When you open the hood, the ECM is on the passenger side behind two large sliding electrical connectors. https://www.youtube.com/watch?v=ayTSF1GkMqg Dial2Fast on youtube shows how to sand and repaint this module which has a rusting problem, as nissan built it into the 2004-2007 models exposed to the elements. 2008 - 2012? they drilled a hole underneath so it wouldnt sit in water when it rains. The video will save you a lengthy read on how to get to it. I see your post was 3 years ago so you may already know this