RepairPal Certified shops can diagnose and repair your 2012 Nissan NV2500. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
It's always under the dash, look left to right under the dash under the driver's side. I do not know first hand where, but it's simply always there. Once in a while, I've seen it on the passenger side, but almost never.