How do you reset ecu on 2011 Nissan Altima?

To reset the ECU on a 2011 Nissan Altima, disconnect the negative battery terminal and leave it disconnected for about 15 minutes. This allows the ECU to reset and clear any stored trouble codes. After the time has elapsed, reconnect the negative terminal, and start the vehicle to allow the ECU to relearn its settings. It's advisable to drive the car for a short distance to help the ECU recalibrate.