This bulletin applies to 2015 and later Infiniti vehicles. The MIL may be on, with DTC P0603 stored (ECM back up/circuit).
1. Confirm that battery voltage is 11 volts or more, with the ignition on/engine off. While checking the battery voltage, make sure that the battery cables are clean and tight. Resolve any low battery conditions before proceeding.
2. Connect C-III plus VI to the vehicle.
3. Open C-III plus on the CONSULT PC.
4. Turn the ignition on but do not start the engine.
5. Erase DTCs.
6. Turn the ignition off.
7. Turn the ignition on and wait for at least 1 second.
8. Turn the ignition off and wait for at least 10 seconds.
9. Repeat steps 7 and 8 10 times.
10. Turn the ignition on.
11. Confirm that P0603 is not stored.
NOTE: P0603 is often the result of low battery voltage, a discharged battery or battery terminal disconnections.