Time for a Nissan Reset
Nissan Altima vehicles from model years 2015 through 2018 may need a reset if DTC P0603 is stored for the ECM back up circuit.
This bulletin applies to 2015-2018 Nissan Altima vehicles. The MIL may be on accompanied by DTC P0603 stored for the ECM back up circuit.
Confirm that battery voltage is 11 volts or more with ignition on, engine off. Erase the DTC. Make sure that battery cables are clean and tight. Connect the C-III plus VI to the vehicle. Open C-III plus on the CONSULT PC.
Turn the ignition on but do not start the engine. Erase the DTCs. Turn the ignition off. Turn the ignition back on and wait for at least one second. Turn the ignition off and wait for at least 10 seconds. Repeat these steps ten times. Turn the ignition on. If P0603 is not stored as a 1 st trip DTC, the procedure is complete.