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.
A small number of customers may experience a Malfunction Indicator Lamp (MIL)
illumination. Upon further investigation a technician may find one of more of the following
Diagnostic Trouble Codes (DTCs) set in the PCM memory.
? P2281 - Air Leak Between MAF And Throttle Body.
? P1477 - Intake Air Diverter Valve Position Sensor Circuit Shorted To Ground.
? U1421 - Implausible Ignition Key Off Time Received.
? P026B - Injection Timing Performance.
In addition to addressing the above DTCs, the following powertrain system
improvements/enhancements are also included in this software release.
? 68RFE Transmission Shift Quality Improvements for low speed First to Neutral and
Neutral to First (Garage Shifts).
? Charging system improvements for single alternator applications (Changes the
cutout threshold from 600 to 500 RPM).
? Diesel Exhaust Fluid (DEF) system calibration improvement during Stationary
Regeneration.
? Cold idle speed stability improvement.
? Charging system improvements for dual alternator applications.
? Torque increase to 865 ft/lbs (D2 vehicles equipped with the Aisin transmission
sales code DF2 only).
? Fuel Filter Minder calibration changes.
? wiTECH Fuel Pressure Override and Fuel System Run Up test improvements.