Flash: 6.7L Diagnostic And System Improvements
This bulletin involves reprogramming the Engine Control Module/Powertrain Control
Module (ECM/PCM) with the latest available software.
DTCs have been changed from a one trip fault to a two trip fault:
· **P0421 - Catalyst 1 Efficiency Below Threshold Bank 1.**
· P2280 - Air Flow Restriction / Leak Between Air Cleaner And MAF.
· P203C - (Diesel Exhaust Fluid) Reductant Level Sensor Circuit Low.
· P208D - (Diesel Exhaust Fluid) Reductant Pump Control Circuit High.
A small number of customers may experience a Malfunction Indicator Lamp (MIL)
illumination. Upon further investigation a technician may find the following Diagnostic
Trouble Codes (DTCs) set in the PCM memory:
· P2281 - Air Leak Between MAF and Throttle Body.
· P218F - Reductant No Flow Detected.
· P0218 - Transmission High Temperature Operation Activated (68RFE Only).
· P0868 - Line Pressure Low, MIL Action (68RFE Only).
· U110E - Lost Ambient Temperature Message.
· P205E - (Diesel Exhaust Fluid) Reductant Tank Temperature Sensor Circuit
Intermittent (setting when the block heater is plugged in).
In addition to addressing the above DTCs, the following powertrain system
improvements/enhancements are also included in this software release:
· **Reduction in engine noise during regeneration at idle.**
· 68RFE Transmission Overall Shift Quality Improvements.
· Test results fix for partial range misfire (68RFE Only).
· Ambient Air Temperature Improvements.
· Stationary Desoot with wiTECH Fix.
· OBD Misfire Monitoring Improvement (68RFE Only).
