Nissan Battery Issue
This bulletin applies to 2015 and later Nissan vehicles (except Titan trucks equipped with a Cummins V8 diesel engine). The MIL may be on, with DTC P0603 (ECM back up/circuit) stored. This is often the result of low battery voltage or battery terminal disconnections.
Confirm that the battery voltage is 11 volts or more with ignition off. Erase the DTC.
Confirm that battery voltage is at least 11 volts with ignition on. Connect 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 DTCs.
Turn ignition off. Then turn ignition on and wait for at least 1 second. Then turn ignition off and wait for at least 10 seconds. Repeat these steps 7-8 times.
Turn the ignition on and verify that P0603 is not currently stored as a 1st trip DTC.