Switching the ECU (ECM) Relay with the Fog Light Relay will tell you if the ECU Relay was the culprit, and get you where you are going. It is the Relay that they updated. Although a new IPDM P/N exist, we haven't found any evidence that the design inside the board was changed, though the Relay has been.
The new Relay is available et the Dealers for just about $3. So feel free to pick it up there.
The original ECU Relay had a built in Diode, unlike the other Relays. This feature protected the ECU, but shortened the life of the Relay.
Nissan uses a different source of Relay now, and it is best to buy it from them if needed. In the very early years, Nissan was changing out complete IPDM, not the relay. This eventually changed. Ask for Warranty coverage first.