This bulletin applies to 2015 Infiniti Q50/Q60, 2015-2019 Q70, 2015-2017 QX50, 2015 QX60 and 2015-2017 QX70 vehicles equipped with multi-port injection (MPI). The MIL may be on accompanied by DTC P0603 (ECM backup circuit). Confirm that battery voltage is 11 volts or more, with ignition on (engine off). Erase the DTC. Perform DTC confirmation steps in the following service procedure. Confirm that 1st trip DTC P0603 is not stored. This DTC is often the result of low battery voltage, discharged battery or batter terminal disconnections.
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 DTC. Turn ignition off. Turn the ignition on and wait for at least 1 second. Turn the ignition off and wait for at least 10 seconds. Repeat the ignition on/off procedures ten times.
Turn the ignition on. If P0603 is currently stored as a 1st trip DTC, refer to the ESM for further diagnosis. If the DTC is not stored as a 1st trip DTC, the service is complete.