Flash: 6.2L / 6.4L Diagnostic And System Improvements
This bulletin involves reprogramming of the Powertrain Control Module (PCM) with the
latest software.
A small number of customers may experience one or more of the following symptoms
and/or a Malfunction Indicator Lamp (MIL) illumination. Upon further investigation the
technician may find one or more of the following Diagnostic Trouble Codes (DTCs).
Symptoms:
? Unable to accurately increase or decrease the cruise control set speed using the
resume or set buttons while the instrument cluster is set on metric units. Instead of
changing vehicle speed by 1 KPH when pressing the buttons, the vehicle speed will
increase approximately 1.6 KPH.
? Slight spark knock condition during aggressive high speed driving which may
prevent the vehicle from achieving maximum top speed.
DTCs:
? P1217 - Active Exhaust Valve 1 Performance
? P121B - Active Exhaust Valve 2 Performance
? P2227 - Barometric Pressure Circuit Performance
