A “small number” of customers owning a 2014 Chrysler 300 equipped with a 5.7L engine and built on or before Sept.  4, 2013, may experience a MIL on. The technician may find DTC P1621 (O2 sensor reference voltage circuit low) and P1622 (O2 sensor reference voltage circuit high).

Using a scan tool, verify that all engine systems are functioning as designed. If other DTCs are found, address these before proceeding.

Install a battery charger to prevent battery voltage from dropping below 13.2 volts or rising above 13.5 volts.

Reprogram the PCM with the latest software using release 14.01 or higher.