My check engine light came on the other day for this code but I have had family in town and no time to look at the car but plan to diagnose it this week. Does anyone have any tips for diagnosing these or know the common things to check first? I have all the needed tools and equipment to test the code but wanted to check if anyone had any pointers!

I searched and came up with nothing so I figured I would start a thread and post my fix to help future members who may have the issue.

I don't have any experience on the M, but on the 99 Maxima I had this code was a pure PITA. The EVAP system goes the length of the car.

Did you fill up recently? It could be as simple as a not-fully engaged gas cap (or one that's bad - they do go bad) or your EVAP canister (usually in the rear of the car by one of the wheel wells). Or it could be one of the 10000 million feet of hose anywhere in between.

I left the repair industry last year but have 12 years experience managing and running auto repair businesses so I know EVAP codes are some of the biggest pains to diagnose and usually require a smoke machine BUT a P0443 code defined is - Evaporative Emission Control System Purge Control Valve Circuit meaning it can't be a loose gas cap, hose leak or anything like that. It is an electrical malfunction related to the Purge control valve itself. Either a burnt wire, bad ground or bad valve. There are numerous tests to perform but I was hoping maybe it was more common and someone would have an idea of what to test first. I typed it into a technician repair source for common fixes and it didn't come up with anything so that should have been my first sign that it isn't super common on these cars, yet.

I'll have to bust out the multimeter and power probe and just start testing the circuit and valve.

Yeah I wasn't referring to the P0443 code specifically, just EVAP issues. My point was more of a 'good luck, EVAP is the devil' lol. Sorry I can't be of more help . Maybe one of our other knowledgeable members will chime in.

I went out and tested the purge valve under hood and supplied power and ground and I heard it click so I know thats fine. I tested the power and ground to it and thats also fine. I checked the hoses to them and don't see any issues there either.

Next step is to locate the vapor canister and check the vent control solenoid on that too.